Posts Tagged ‘anodizing’

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Cycling season is upon us which also means the agony of getting into riding shape has begun. When I ride my road bike I typically ride by myself. I like zoning out and riding at my own pace. What I also like are all the training numbers that can be had, and analyzed, based on my own riding performance. I monitor heart rate and cadence as the primary indicators that help me determine my progress and abilities.

This year I began using the Strava app on my phone which allows me to track more of my riding data. I won’t go into detail about the app since the website would do a better job of explaining it however I will say that it is packed full of data that helps determine the pace I am riding at and how I improve.

Since I want to have my phone visible when I ride I wanted to have it mount in a location on my handlebar stem. There are companies that offer phone mounts for bicycles however the ones that I looked at all had some minor issues that I did not like. I figured I had a Saturday afternoon to kill so I thought I would see what the milling machine could produce for a mount.

I spent a few sleepless hours, the night before, lying awake in bed mentally engineering the mount. Once I had the neuron blueprint made I caught a few hours of sleep then headed into the shop and starting chipping out some 6061 aluminium.

The criteria were fairly basic. The mount needed to be solid; I didn’t want Velcro or rubber bands holding it on. Second concern was that the phone had to mount to it quickly. Third thing was that I wanted the mount to accommodate my Otter Box case. With these 3 personal requests I came up with a plan. The rest is of the story is told below.

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I started off with a section of 1.500″ x .500″ flat 6061 aluminum and began hogging out metal to form a clamp for the phone.

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With the middle sectioned out I started to open things up from the outside.

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A little more milling and I finally had something that resembled the clamp that I dreamt up the night before.

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I required a 6 mm thread in the center hole that would eventually provide the clamping force adjustment.

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I am not a weight junkie however there is no need in carrying around anything that is not required. I milled off some extra aluminum that was not necessary.

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With the clamp roughed out it was time to start on the base. The first order of business included milling out a section to accept the previously build clamp.

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Next step involved hogging out all the unwanted aluminum. My projects sometimes get “chunky” and I did’t want that to happen on this one.

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I needed 2 flanges that would allow me to bolt the holder to the bike and the other to help keep my phone centered. Out came the boring head and things were trimmed up.

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Here it is just rough machined. Not finished yet.

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I test fit the mount on the bike and determined things were, in fact, too “chunky”. I decided that the smaller flange I previously cut in order to keep my phone centered really was not required. Therefore it was time to undo my work. I set the base up on the rotary table and cut off the top section on the mount which included my previously machined smaller flange.

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It is definitely looking better, and lighter, having been cut down.

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As I continue to lighten things up I cut some speed holes. The one exception was the bottom 6 o’clock hole. It was drilled and tapped, you will see why later.

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Here are all the components that make up my holder. You can see a knob, which I didn’t show any pictures of machining it, which will be used in conjunction with my clamp.

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Onto the finishing portion of the project. The mount will get anodized in order to protect if from the elements. Of course I say elements because it needs to sound like I need a reason. Truth is that it just looks really cool when anodized. All the edges and surfaces got touched up and then were hit with 2 stage buffing. Then thoroughly cleaned and ready for anodizing.

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Here they sit in a sulfuric acid bath and soak for a couple hours while getting bombarded with electrons.

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Onto the coolest part of anodizing. 5 minutes in the Red Bordeaux dye resulted in a fantastic shade of red.

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This is the clamp fresh out of the dye.

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Because there is always 1 person that says “How much does that weigh?” the answer is 109 grams. Yes it is weight, get over it!

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Here you can finally see how the mechanics of the clamp works. The knob allows me to tension up the clamp against the soft, flexible, section of the Otter Box phone case.

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The base mounts in place of the steering head center cap. It is solid and secure.

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The single tapped hole in the array of speed holes was done in order to allow me to store the clamp when the phone is not installed. I simply spin the clamp onto the base and that way it won’t get misplaced.

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Here you can see how the entire system was designed, and built, to work. The phone is mounted very securely and has no movement.

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All that is visible from the top side are the fingers that wrap around the sides and clamp. I am happy to say that I have cycled multiple times using the mount and there are no issues.

 

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I received a notice from my daughter’s school looking for silent auction donations for an upcoming fundraiser. The funds were going towards the school’s parent council and are to be used to fund programs, and purchases, not covered by the schools budget. I thought it would be fun to donate something that was hand machined in hopes that my labor would score a decent bid and therefore increase the funds collected from the auction.

I wanted to fabricate something that would appeal to a wide audience and so I settled upon machining a yo-yo. I figured both kids and adults could enjoy the pleasures that come from rotational energy. The yo-yos I build are not pro style trick units, they do not run ball bearing axles or friction pads. The units I make are for the pure novice that can appreciate the joys that come from classic design.

The first order of business was to change the name. Although yo-yo is a generic, non-trademarked, name I felt it was too immature. Therefore instead of machining a yo-yo I opted to machine a Vacillating Vertical Pendulum. The concept is the same, only the name has changed.

Since the pendulum will be placed on an auction block I opted to machine a custom storage case for it as well. I have posted pictures of my “yo-yos” in the past but have not dedicated an entire post outlining the process. The following is jam packed with pictures showing the procedure I have developed to make a Vacillating Vertical Pendulum.

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The entire process starts off with a section of 6061 aluminium. Normally I use 2.250″ stock however I was out so I was forced to start with a 2.500″.

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Since there are a total of 18 holes being drilled in each half I try and keep the starting thickness down to a minimum. The final thickness of each half will be .500″. Working with a .550″ thick section allows .050″ for rough, and finished, machining.

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First machining step involves facing the one side and then drilling, and tapping, a 6 mm hole .300″ deep. Look at me splitting metric and imperial.

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To make the rest of the machining easier, and to avoid damaging the finish, I use an arbor I made that has a 6 mm stud.

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Using the arbor I face the opposite side. No need to clean up the diameter yet.

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With the 2 blanks built it is time to move onto the milling machine and set it up for the drilling of the lightening holes.

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The milling machine gets dialed into the center of the blank.

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Next I use the DRO (Digital Read Out) to program in the placement of all the holes.

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All the holes get marked using a centering drill.

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The twelve outer holes get final drilled using a .250″ drill bit. The inner 6 holes are opened up to .3125″.

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The blanks start off at 110 grams (there is that metric again)

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The 18 holes shave off 22 grams of weight.

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Next it is back onto the lathe to clean up the inside face of the blanks.

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These are the blanks prepped and ready to get the final weight machined off.

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Here the diameter gets spun down to a final dimension of 2.200″.

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As previously mentioned I would typically start with 2.250″ stock however in this case you can see the amount I had to take off from the 2.500″ I actually started with.

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Using the arbor in the lathe chuck I face off enough material to bring the thickness down to a final .500″.

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In my quest to shave off more weight I set up to trim the outer face at a 14 degree angle.

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With the face trimmed up I chamfer the corners using a 30 degree angle.

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With the final machining complete I clean up the edges using 320 grit sandpaper. The 30 degree chamfer, performed in the previous step, allows for a sanding of a smooth corner.

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Here you can see the rough clean up on the left as opposed to the final machining on the right.

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Total weight has now come down to 41 grams.

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With all the machining completed it is now time to move onto the second phase of the process. Since the units are going to be anodized it is crucial that the surface finish is perfect before zapping them in an acidic bath. To make polishing easier I decided to build an arbor to help keep the machined faces from “getting away”.

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2 stage polishing is adequate for the anodizing process.

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The foreground face has been machined where as the background face has only been sanded using 320 grit and Scotchbrite.

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This picture makes it obvious I am building 2 Vacillating Vertical Pendulums.The second one is for a friend. The polished faces have now gone through a rigorous cleaning process. Aluminum filler rod has been wedged into the 6 mm holes and they are ready to get dunked in the ano bath.

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Here they all sit in a bath of sulphuric acid for 2 hours with approximately 2 amps of current flowing though the liquid.

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The anodizing process is complete after the 120 minutes, it is evident that the process worked by the change in color to a light grey.

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The unit that is being donated for the silent auction is being dyed a red bordeaux finished. Total time spent in the color bath is approximately 10 minutes. After that the units get boiled in water for 30 minutes to seal the color in.

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This picture is kind of just stuck in the middle of everything. The axle shaft is cut from a 6 mm stainless steel threaded rod. Here the bushing , that the axle slides through, is being cut from a section of .3125″ aluminum.

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These are the 2 dyed, and sealed, pendulums. Pretty!

 

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I like to add a silver lining around each hole using a chamfer bit on a hand drill.

 

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Since the Vacillating Vertical Pendulum requires a place to be stored I thought that a custom case would be in order. Here I started by machining down a section of 1.000″ 6062 aluminum to act as a storage perch.

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A radius sliced into the top will allow for some stability when resting the pendulum on its stringed axis.

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The base of the storage case was, once again, trimmed out from aluminum. A threaded 10 mm center hole will allow the center perch to attached.

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The base of the storage case received a coat of matte black powder and then got baked at 375 degrees for 15 minutes.

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Time to clean and assemble everything. The pendulums received a hand waxing with some Collinite’s #850.

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Here are all the components, before assembly, that make up the entire project. The glass cover was purchased and the base was machined to fit.

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The center storage perched was screwed into the base. Note the humidity control holes that was drilled into the base to allow for strict climate control inside the case.

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The storage case received a GG decal to finish things off.

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To ensure that the person who purchases the item knows that it is authentic a certificate, and specification document, was created.

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The plasma table CNC build has officially gone into fabrication phase. I have sacrificed multiple, sleepless, nights coming up with a game plan and determining the best sequence to build the table in. I have opted not to use any existing plans but instead engineer the table my way. I have a “big picture” in mind however all the details that are required to ensure the concept will be completed are yet to be determined.

Most tables are typically started by building the main frame. Since there are so many unknowns as far as gantry sizes and, more importantly, X,Y,Z travel dimensions I decided I am going to start from the center of the universe. In this case I am going to build the entire table around the tip of the plasma torch. This would mean I begin with my Z axis.

Since part of the construction of the Z-axis involves its ability to move along the X-axis I needed to come up with a linear movement system. X and Y axis linear movement methods are obviously nothing new. There are multiple systems that a proven to work well. My favorite has always been the Dualvee Bearing design coupled with the Vee rails. It takes care of both the radial and axial movements all in one shot and it does it in a fairly compact set up.

Since the whole point of fabricating the CNC is to actual “fabricate” I wanted to avoid purchasing as many components as possible and instead build the items. Coming up with a simple linear motion system that I had the skills, and equipment, to build was tough. I didn’t want to clutter up the sliders with aluminum plates housing 8 bearings each just to keep things smooth and straight.

After much thought I took some inspiration from the Vee bearing design and opted to build my own version but without the Vee. My version would incorporate a radius bearing that would ride along a 4140 alloy rod. If the design works it will control the radial and axial loads just like a Vee bearing does.

Weight of the table is a huge factor and this will become evident why later on in the build. So after a bit of experimenting I came up with a system to accurately machine radius bearings out of aluminum. Aluminum is not exactly the first choice for bearing material however in my case the loads are not massive plus the ability to anodize aluminum will certainly add a layer of hardness. The following outlines the first steps in building the CNC table by starting with the axis bearings.

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People often ask for the plans of some of the things I build. I figured I would start by posting the intricate CAD drawings of the bearing assemblies. Here is all the information for the world to see.

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Here are the bearings in various stages of production. They are all machined from 2″ 6061 round bar. The outer finished dimensions are .750″ wide with a 1.975″ diameter.

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The blank is hogged out with a 1″ drill bit on the lathe.

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Next it gets bored out down to the .001″ to accept the press fit bearing.

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A custom fabricated arbor was required in order to perform the external machining using both the lathe and the milling machine. Here is the steel arbor I built to secure the aluminum blanks.

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The outside diameter gets lathed down to 1.975″ before it gets moved over to the milling machine.

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The rotary table was set up vertically and the blank gets secured in order to allow a .125″ deep cut using a .675″ endmill.

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This is the final machined bearing housing before it goes into finishing stage.

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All the bearing housing then got a 2 stage polishing in order to smooth things up.

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Here is the set of 8 ready to move on to the anodizing phase.

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In order to remove all of the cutting oil and polishing compounds the housings recieve a soaking in a heated solution of SP degreaser.

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After getting a good scrubbing in hot soapy water the units get rigged for hanging in the sulphuric acid anodizing bath.

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Everything gets hung and electrically connected ready for a 2 hour soaking.

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The power supply gets connected to the bearing housings and 4.50 amps at 15 volts is dialed in for 120 minutes.

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These are what the housings look like after they are anodized. The shiney, polished, aluminum turns to a dull light grey color.

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All the housings then recieve a dip in the heated orange dye tank. To keep the color consistant they are all timed for an 8 minute bath.

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Here are the housings fresh out of the dye tank.

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Time to press the bearings in. In order not to damage the finish on the housings I machined a couple of bushings that I used to keep the housing, and bearing, straight and protected while they get mated using the vise.

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Finished product. I will be curious to know how well the anodized surfaces will stand up to wear and tear. Having them colored orange will make it easy to determine the extent of wear they are suffering from.

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So it would appear that I have got myself into a groove of machining projects that can be completed in an evenings worth of time. They allow little commitment on my part yet yields decent amounts of satisfaction, in today’s world I think I have dialed in what we are all looking for. I typically live by the words “a well planned project is a project half done” however in this case a “project that is winged is a project that that wasn’t planned but turned out alright”.

I got myself into a yo-yo groove. A number of years ago I researched yo-yos and came to learn that the technology has advanced since I was a kid. Now the pro yo-yos are all ball bearing-ed, housing friction discs, and strung with your choice of left, or right hand, wound string. Really I just wanted a yo-yo like the yellow wooden one I had when I was lad. So I got my hands on a typical, non-pro, yo-yo. Took some dimensions, weighed some weight, and went to spinning on the lathe. Would you like to see?

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I do not have very many build pictures to post. All the units where built from 6061 aluminum. I made 2 different versions, an adult version using 2.250″ stock and a child’s version using 2″ stock. The milling machine digital readout was dialed in to hog out some holes to lighten the overall weight.

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These are the rough machined blanks. The centers are threaded to accept a stainless steel 6 mm threaded rod that is housed in a 5/16″ aluminum axle.

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These are the finished machined spinners. I set the blanks up on the lathe and then tapered down the sides until I achieved the weight that I wanted.

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Time to toss on some color. Some of the units got anodized and then dipped in some colorful dye.

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All the colors hung to dry after coming out of the dye tank.

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This one was built for a good friend of mine, Dave, who is always around to help me out when needed (except when he is in Disney World). He wanted his favorite sports team colors so this yo-yo went copper and blue.

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This 2 tone unit weighs in at 72 grams and sports an orange poly string.

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This was the child’s version I built and dyed florescent pink. I left it in the dye tank a bit too long so the “florescent” doesn’t pop as much as it should. The smaller 2″ diameter, along with the larger holes, brings the weight down to 47 grams.

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The original plan was to dye both sides pink however I ran into a slight issue with the anodizing. I ended up having a poor electrical connection while soaking the yo-yos in the acid bath and the 1 side of the pink yo-yo never anodized. Because it didn’t anodize I couldn’t get it to take on the dye. I decided to throw it back on the lathe and brush finish the failed side. I think it looks better this way with the two tone.

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This purple one was built just because. It is built to the same dimensional spec as the copper/blue one. I have logged some decent spin time with this one and I am pleased with the performance level. Good weight, good feel, good whip, good spin.

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This was my original prototype. In weighs in at a hefty 104 grams! Yes, it is not for the weak fingered but it works. It does, however, start to take it toll on the digits. I used the specs of this y-yo to machine my more successful anodized units from. The main difference is that I shaved down the thickness of the sides in order to achieve better weight.

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You can see how thick this one is. I initially got the spec from an original yo-yo.

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So this is part 2 of how I perform LCD II home anodizing in my garage. If you missed part 1 you can view it here.  In part 1 I had dealt with surface preperation and cleaning. Part 2 will demonstrate the remaining steps 3,4 and 5 which will finish the parts off with anodizing, dyeing, and sealing. Enjoy!

3. Anodizing

This is the step that everyone wants to hear about. If you have decided to skip over reading steps 1 and 2 that I posted yesterday then I would like to reiterate a previous statement of which I said “if you spend 5 minutes completing a project then it will look like you spent 5 minutes completing the project”. However I also said that this is not an instruction guide so let’s move on shall we?

I buy my distilled water in 20 liter box form for $7 a box. To set up the anodizing line, plus the dyes, it take a lot of water. I have gone through over 150 liters by now.

The basic physics that surround anodizing are fairly simple. You take your aluminum part and suspend it in a bath of sulphuric acid and then run electric current through it. There is lots of information out the internet that explains all of this if you care to research it further. The set up I use is based on a 5 gallon plastic pail. Although my set up is small it is easily expandable into larger containers to accommodate larger projects. My 5 gallon bucket has a mixture of battery acid and distilled water in it. I mix the solution 3 parts water to 1 part battery acid (by volume). I struggled with this ratio initially however I have since located documentation which helped me dial it down to the 3:1 ratio. As I previously stated this post is not and instruction booklet and that there are certain safety precautions to be taken. Right now is the only warning I am going to give. AAA = ALWAYS ADD ACID! When mixing a sulphuric acid solution you never pour the acid into the bucket first and then add water. ALWAYS pour the water in first and then add the acid.

The battery acid is purchased in 5 gallon boxes. The acid lasts a long time as long as I am careful not to contaminate my ano tank.

 With the acid in the bucket I now needed a cathode. A cathode is a metal electrical conductor that will be hooked up to the negative side of the power supply. When anodizing the 2 most popular types of cathodes are lead or aluminum. I opted to build a couple of cathodes out of 6061 aluminum sheets and then gave them a bend to help them hug the sides of my bucket. The size of the cathode is I important. It needs to have at least the same square inch area as the part is that I am anodizing. As far as I know a cathode size in excess of the anodized part is not a factor.

The cathode plates I made from 6061 aluminum and welded on some tabs to be able to wire the negative connection of my power supply to. The brass wing nuts make for quick and easy electrical connections.

 Now comes the anode which is the metal electrical conductor that is hooked up to the positive side of the power supply. The anode is the part that I am anodizing. The anode needs to be suspended in the sulphuric acid solution. To do this a wire needs to somehow be attached to the part. I have been using up my 4043 aluminum TIG welding filler rods to do perform the task. I need to ensure I have good contact between the filler rod and my part in order to obtain a good flow of electricity. I usually end up bending the filler rod to gain a certain thickness and then I force it into a threaded hole of the part. Every situation requires some ingenuity.

These are the parts all cleaned and ready to be immersed into the ano tank. The purpose of this picture is to demonstrate how I wedge my aluminum hanging wires into the parts to ensure I have a good electrical connection.

 There are many different ways to build racks for the anodizing tanks. Mine is not great however I will spare you the details. Improvements can be made with experience. My aluminum 6061 cathode plates are placed into the bucket of sulphuric acid and the negative side of my power supply is wired to them. I then hang my anode (the part I am anodizing) to the rack that sits on my bucket and connect the positive side of my power supply to it.

This is my first rack I built to fit onto a 5 gallon bucket. It is made from 6061 aluminum. The wing nuts allow me to make my positive connection from the power supply. The 4 tabs with holes in them allow me to slide my agitation lines into them. The round rod to hang the parts from is not ideal, my plans are to change this to a better system.

 At this point we need to take a slight detour however this is a good detour. The following information is what spares newcomers from massive amounts of frustration and failure. It has to do with figuring out how much current to run through your bath and for how long. Again I feel like I need to reiterate that this is how I anodize, there are other ways however I know, from first hand experience, that this way works. I use what is called the 720 rule. The rule goes like this. It takes 720 minutes at 1 ASF (amp per square foot) to anodize a part with a 1 mil (.001”) thickness. Now if you are like me I was thinking that I had to run my part in the solution for 12 hours. No you don’t and this is why. This home type system uses LCD (low current density); I am not going to explain this as it is irrelevant. What this means is that I am going to use 6 ASF to base all my calculations from. Why 6 ASF? Again…at this point it is irrelevant for this post, email me if you really need to know. All I will say is that 6 ASF proves to work well for Type II anodizing. So on with the math. If we anodize with 6 ASF to obtain 1 mil thickness then based on the 720 rule we only need to anodize for 720/6=120minutes. That’s right 2 hours. Can you cut that time down? Yes however your thickness will not achieve the desired 1 mil. Who cares if it isn’t 1 mil? 1 mil creates deeper pores which allows for the colored dye to soak in and produces better colored results. Are you still with me? Good let’s keep going. Next step in the calculation is where I need to know how much surface area is on the part I am anodizing. The 720 rule is based on 1 square foot of surface area. If I want to anodize a flat piece of 6061 aluminum that is 2” x  4” x .125” thick I need to add up the surface areas of all 6 sides. I won’t perform the math in front of you however the total surface area of all 6 sides is 17.5 square inches or .122 square feet. Since we require 6 ASF per 1 square foot this would equate to requiring .73 amps of current (6ASF x .122 sq ft) for .122 sq ft. So there you have it. What I need to walk away with at this point is that I am going to anodize my sample part for 2 hours at a Constant Current (CC) of .73 amps for 120 minutes to obtain 1 mil (.001”) of thickness. If you can’t, or do not want to, comprehend this then go to this handy online calculator that will do the math for you. You can even run my sample numbers in it to double check my work.

In the case of my demonstration trigger and receiver I calculated out the total square inch surface area to be 31.58 sq. in. which results in a target current flow of 1.32 amps for 2 hours in order to achieve a 1 mil anodized coating.

This is my power supply set up. The power supply is capable of delivering 50 amps. Most of my parts are so small that I am unable to dial the current in using the power supplies ammeter as it is not accurate in the low end of the scale. I use a multimeter wired in series to allow for accurate control of the current. The box on top that houses 2 light switches simply allows me to bypass the meter quickly.

 So let’s get back to the anodizing. I have my part suspended in my bath, my wires hooked up and I am ready to flick the power on. But wait…what exactly am I powering up? Yes you need a power source. I use an ASTRON VS-50M 15 volt 50 amp DC power supply that I was able to pick up used. Some people use manual battery charger and some use car batteries. I cannot comment on these methods. Using a controllable power supply allows me to abide by the 720 rule. If you haven’t already done the math you will note that a 50 amp power supply limits me to anodizing a part no larger the approximately 8 square feet (720 that one). On my power supply I always max my voltage and allow it run where it wants. The power supply is capable of providing 15 volts and typically runs around the 13 volt mark. It is the current I limit. Since the ammeter on the power supply is not accurate enough for me to dial in small current I simply install my DVOM in series with my positive wire which allows me to control the currently accurately while I monitor it with my meter.

This is the ano tank with the parts suspended and ready to go. You can see the cathode and anode connections. I add a couple of extra jumper wies just to ensure I have a good electrical connection to my parts. The red lines are my agitation lines. You can also see the 150 watt aquarium heater that I use to bring the ano bath up to temperature.

 So there you have it. The anodizing process is under way. I have set my timer for 2 hours and things are starting to bubble. Since it is now a waiting game I will take this moment to mention a few things that relate to the anodizing tank. First one is temperature. I anodize with my sulphuric acid temperature at 72 degrees F. If the mixture is a bit cold from sitting in the garage I have a 150 watt aquarium heater that I use to bring the temperature up. I should note that the anodizing process creates heat and why wouldn’t it? If you think about it and you anodize a part that is 8 square feet it would require 48 amps of current for 2 hours. That’s a lot of current which will start to create a lot of heat. You need to keep the heat under control. Some set-ups use ice and others use cooling towers. In my case I use nothing because all my parts are so small that the temperature in the bucket only ever rises a few degrees. When only using a few amps to anodize the heat is not a factor.

This picture is nothing more then demonstrating what temperature I anodize at. As the 2 hour process progresses the heat in the tank rises. Because my parts are small the increase in heat is not a factor.

 Next thing to bring up is the agitation. I have read that some people use aquarium pumps to agitate the sulphuric acid bath while the part anodizes. I figured I have a huge tank of compressed air sitting in the corner so I wasn’t going to waste my money on a pump. I took some ¼” plastic air hose, the stuff used for pneumatic cylinders, and created my own set of 4 air jets. I hooked them up to a regulator and have myself a very low pressure, low volume agitation system. Do I need to agitate? I don’t know I just do. I believe there are many others that do not.

I tee into my shop compressed air system to provide the air agitation in the ano tank. I regulate the pressure way down and then fine tune the volume using a 1/4" ball valve. My shop air is fairly clean and therefore I do not think using it will contaminate my tank.

Here you can see the air agitation at work. I do not know if the anodizing process will suffer any without agitation however I get results from using it so I will continue to do so.

While we wait for the part to anodize I thought I would mention that anodizing stinks. If you have ever smelled a sulfated car battery then you will know what I am talking about. I have a ventilation fan in my garage that I run. I am not sure I would ever anodize in my house. Apparently there are products available that eliminate the odor however I have no experience with them.

As the parts anodize you will start to see the aluminum part change color along with the wire it is suspended from. The part goes from a shiny metal to more of a dull grey. This is good. If it doesn’t it is possible that the part has a bad electrical connection.

Throughout the 2 hours of anodizing I occasionally check the amperage and tweak my current to ensure that I maintain the calculated current required.

So 2 hours has passed and this is where all the hard work starts to pay off. This is also where the fun comes in. After 2 hours of the part sitting in the bucket having electrons forced through it it can now be taken out and rinsed with distilled water from the spray bottle. And that is it! The anodizing process is complete. From here the part can either be dyed and sealed or just sealed.

Here are the anodized parts after 2 hours of sitting in the ano tank. I have rinsed them off with distilled water at this point. They both have slight color change to them. Take note of the color on the aluminum hanging wires. This is a sure sign that the electrical connection was good.

4. Dyeing

These are some business card sized color samples that I made previously. I use them to reference to. I labelled each sample with the amount of time they spent in the dye tank. In the case of the trigger and receiver Jason requested Electric Blue for the receiver and Green SCG for the trigger.

I keep all my dyes in 10 liter plastic jugs.

The dye process is quick, easy, and highly satisfying. At this point the pores in the anodized part are opened right up ready to suck in whatever dye color you choose. The process I use involves the same kettle I used in the SP Degreasing process that I outlined in part 1. I dye all my parts in a colored solution heated to 140 degrees F. DO NOT heat the dye too hot as the pores in the part will begin to seal and the dye will not take. Once I have brought my dye temperature up to 140 degrees F I pour it into a suitably sized plastic container and then suspend the part into it. The maximum amount of time a part can stay in dye is 15 minutes. After 15 minutes the part will no longer take on any more color and all you are doing is wasting time. However 15 minutes is the maximum were as there is no minimum. Dyes will color to a different shade depending on how long the part is submersed in it. I have found that with my darker colors like the browns, grays, and dark blues they benefit from only 2 -4 minutes otherwise they get too dark. The reds, greens, and brighter blues work nicely in the 8 minutes range where as the violets, yellows and oranges can handle the full 15. It comes down to experience and the shade of color I am trying to achieve. That is all there is to the dyeing process. It is over fairly quickly.

Once again I use my 1500 watt electric kettle to heat my dye to 140 deg F. I then pour the dye into a suitable sized container to suspend my part into. The dyes are all reuseable.

Here you can see how quickly the dye gets soaked up. The trigger is already a nice shade of green after only 1 minute.

I shot the following video while I dyed the Electric Blue receiver. The video is meant to show how dye time affects shade. I’m not sure the footage captures the affects all that well, it is what it is. The video is just a bit over 2 minutes long. The first minute shows the effects every 15 seconds, the last minute shows clips of the remianing 5 minutes.

Here is a picture of the Electric Blue receiver after having soaked for 6 minutes in the dye tank. It is still a bit wet after being rinsed with distilled water.

Here is a picture of the trigger after spending 6 minutes in the Green SCG tank.

5. Sealing

 Sealing of the part is the final step to the anodizing process. Sealing closes up the pores created by the anodizing process and locks the dye in. The process is pretty straight forward. I suspend the part into a pot of boiling water for ½ hour. That’s it. After half an hour the pores are shut and the dye is locked in. I take the parts out of the boiling water and straight to a white polishing cloth and not a spec of color is evident on the cloth.

This a portable hot plate and dedicated Stainless Steel pot I use for the sealing process.

Here the anodized and dyed parts are suspended in boiling water for 30 minutes. I choose not to use distilled water for the sealing process.

So here is the final product aftering surface prepping, cleaning, anodizing, dyeing, and sealing.

Supplies

When I first started to set up for anodizing I had read through the process and realized that part of the challenge was to collect all the equipment you need to do it. There are places on the web that will sell you complete start up packages that include everything you need. One of these places is Caswell Inc. and they have 2 warehouses located in both the US and Canada. If you check out their site you will be able to find the complete kits and supplies you may need. I am not going to give Caswell Canada top praise as I have run into minor issues with them however they have always provided me the supplies I have ordered in a timely manner therefore I can’t really complain. I will continue to use them.

I did not start with a complete kit instead I opted to piece mine together my way. There are not a lot of “hard to find” items that you need. The following is a quick run down of my equipment;

  1. Battery Acid; purchased from a local automotive parts supplier in a 20L box for around $28 (I think)
  2. Power supply; my Astron VS-50M was found online used. I paid approximately $180 including shipping and had it sent to me from the other side of the country.
  3. Dyes; $13 per color purchased from Caswell Canada. The dye comes in 4 oz bottles in the form of a concentrate. 1 bottle is added to 2 gallons of distilled water. Dye lasts a long time and can be used over and over.
  4. Distilled water; purchased from an industrial supplier and bought in 20l box quantities for around $7. I go through a lot of distilled water when initially setting up my tank and dyes. I must have used over 150 liters by now.
  5. SP degreaser; purchased from Caswell Canada for $26. It comes in powder form that gets mixed into distilled water. 2lbs worth will make 4 gallons
  6. Aluminum de-oxidizer and de-smut; $23 for 1 quart from Caswell. 1 quart gets combined with 2 gallons of distilled water.
  7. Heater for my anodizing tank; $35 for a 150 watt aquarium heater purchased from a local pet supply store
  8. Aluminum hanging wire; not sure of the price on this one. Aluminum wire can be had from any welding supply store. I use TIG filler rod however the wire can also be had in spools for MIG welders. Not a lot of money
  9. Cathode; like I said earlier either 6061 aluminum or lead can be used. I used 6061 that was picked up from my local metal supplier. More then enough cost me around $25. Lead sheets (used for roofing?) can apparently be had at your local hardware store, again, unsure of the cost.
  10. 1500 watt kettle; $10 on sale from any place that sells home small appliances.
  11. Electric hot plate; $25 from a small appliance store
  12. Other items like plastic containers, digital timer, thermometer, spray bottle, dish soap, scrub pads, etc, can all be sourced locally.

I think that is it for supplies however I am sure I have missed something. If you want clarification then send me a message.

Some people dedicate a certain area to set up their anodizing line. This has a huge benefit off being able to work more quickly and in a more organized manor. I have to prioritize what equipment takes up my space and right now anodizing is not at the top of that list. My whole set up is portable and all the equipment gets stored in a plastic bin and kept on a shelf in the garage. The only portion of the entire set up I keep in my basement are the dyes simply because I have space there to sacrifice.

And there you have it. My methods fully exposed. My fingers hurt from typing all this. I need a break…I’ll be in the garage.

There were some questions raised awhile back concerning home anodizing and exactly how it is accomplished. I thought I would share my procedures (good and bad) and show how I have been able to achieve, what I would consider to be, successful Type II home anodizing.

However before I begin I think I need to say the following (I think because I don’t really know). It’s the almighty disclaimer. What I am claiming to dis is I am not a professional and I try things at home. Anodizing involves certain chemicals that can cause good things to go BAD…namely you. Sulphuric acid is used in the anodizing process and as we all know acid can be BAD. I do not want BAD things to happen. So please note the following. This blog posting is not a step by step guide. This blog posting is simply showing how I do my anodizing. I am not going to litter the posting with safety information. Gloves, safety glasses, and respirators are all no brainers. If you don’t know when to use these things then please turn your tools in at the door and find a comfy seat in front of the television. Now on with the show.

These are a set of sport bike race stand spools that I machined for a friend and then anodized.

The type of anodizing I do in my garage is known as Type II, Low Current Density (LCD) , Controlled Current (CC) anodizing. I am not going to explain all this since this is not an instruction guide. There is lots of information out there that can assist in defining the process. If you have specific questions then send them my way, I will do my best to answer them. I will, however, clarify one misconception. Anodizing does not give a piece of metal a cool funky color. The color comes from the dying process after the part has been anodized. Anodizing is the process of building up the exterior layer of oxide on aluminum in order to give it a more durable finish. When the part is anodized this oxide layer is comprised of many small pores. It is these pores that are what absorbs the dye color in the dying phase. The dye provides no benefit other then looks.

Different types of metal can be anodized however the most common home anodizing deals with aluminum. In my case it revolves mostly around 6061 grade. The process can be broken down into 5 stages and they are;

  1. Surface preparation
  2. Cleaning of the part
  3. Anodizing
  4. Dyeing
  5. Sealing

I will attempt to address each step and try to explain how I deal with the challenges of each stage.  As a demostration piece I am going to use a rubber band gun reciever and trigger mechanism that are fabricated from 6061 aluminum. A cyber friend of mine, Jason, sent me one of the trigger assemblies that he engineered, designed, and built to fit into a custom wooden stock to create a dual action rubber band rifle. Very cool set up and mechanism. If you are interested in learning more about Jason’s project you should check out his blog. He has lots of pictures, drawings, and explainations.

1. Surface preparation

This is the trigger and receiver assembly that Jason sent me. The purpose of this picture is to demonstrate the finish I was starting with.

Anodizing hides nothing; I mean nothing (ok maybe it hides a little bit). It is best to assume that any surface imperfections that were present before anodizing will be visible afterwards. Anodizing is not like paint, powder coating, or chroming where the surface gets covered with a different material. Any scratches, nicks, or gouges will be visible afterwards. Therefore part preparation is crucial in order to achieve satisfactory results. In my case I am still experimenting with surface preparation. Some of my aluminum is finished with a 400 grit brushed finish, sometimes it is sandblasted (careful with the blasting, there are things to consider when anodizing blasted parts) and sometimes I polish the part. I have found my best success has come from polishing. Success being defined as the colored dye really “pops” on the polished parts. Since most of my anodizing involves parts I machine on my lathe I use the following to obtain my desired surface prep.

When I am not using my lathe to spin the part while I buff it I am using a 1/2 hp 8 inch buffing motor bolted to my drill press.

  1. With the part mounted in the lathe and spun at 1620rpm I sand with 100 grit sandpaper
  2. Then I move to 220 grit
  3. Step it up to 320 grit
  4. Move onto a fine grade aluminum oxide Scotchbrite pad
  5. 0000 grade steel wool
  6. Then I remove the part from the lathe and put it through some buffing wheel abuse starting with a 8” sisal wheel lathered with black buffing compound
  7. Onto the spiral wheel with a brown compound bar
  8. And I finalize it with a loose buffing wheel coupled with white compound

By this time the part has a mirror finish and any more surface prep would be a waste of time

This is showing the 3 differnt buffing wheels I use along with the compund I use on each wheel. I dedicate wheels to only one compound so that I prevent any cross contamination.

This is the surface prepped trigger and receiver after I performed 3 stage polishing on them. Almost too pretty to anodize at this point.

2. Cleaning of the part

The first 2 stages of the cleaning process is done with acetone first and then the parts gets a good wipe down using wax/grease/oil remover (acetone based).

In my uneducated opinion I would say that out of all the stages to anodizing the cleaning phase is the most crucial. The cleaning process will determine the success of how well the part will dye to the desired color. The parts can have NO grease, oil, wax, or buffing compound on them. There are multiple ways to ensure the part is clean. Again I am going to tell you how I do it, there are other options. The process starts by using a clean cloth and wiping the entire part down with acetone to take the initial grime off. Next I move onto a professional body shop wax/grease/oil remover solution. I use another clean cloth and, again, wipe down the entire part.

This is the SP Degreaser in powder form. The stuff I order is 2 lbs. worth which is enough for 4 gallons of distilled water. The package states to heat to 190 deg F however I find that 160 deg F works.

Now it’s time to start the serious cleaning. I use a product called SP Cleaner/Degreaser. It is a biodegradable product that is used in cleaning food processing equipment. I heat the cleaner to 160 degrees F and then submerge the part in it for 5 minutes. It’s now time for me to peek inside the back door of the house and perform a quick visual to see if the wife is anywhere in sight. No? Good! Now I take the part and quickly move to the kitchen sink. It is here where the next phase of cleaning takes place. I need to move fast because the wife could be lurking and end up silently standing behind me while I contaminate her kitchen with  my “disgusting garage dirt”. It is here where a pair of nitrile gloves are put on and then washed with hot soapy water. It is at this point where the part no longer gets touched with ungloved hands. I use dishwashing soap and a nylon brush (and sometimes a toothbrush) to scrub and scrub the part. After cleaning with dishwashing liquid the part then needs to pass the water break test.

Because many of the parts I work with are fairly small I am able to work using just a 1500watt electric kettle. Here I heat the SP Degreaser to 160 deg F and suspend the part in it for 5 minutes. I keep the used degreaser and just pour it back into my jug. The sediment that has been cleaned from the part is visible at the bottom of the kettle.

The water break test is a test which involves holding the part underneath a stream of water and inspecting how the water runs off the surface. If you have ever washed a newly waxed car you will notice that the water beads. Waxed car = beaded water, this is good. Cleaned anodizing part = beaded water, this is BAD! The water needs to cover the part in almost a mirror type finish; it needs to flow off the part in one continuous sheet. This is the indication that the part is free from wax, oil, and grease. This is good.

Here I head into the house to clean the parts with dishwashing soap and hot water. At this point I put on a pair of nitrile gloves and wash them first with soap and water. I scrub until the parts pass the water break test. After this cleaning stage the parts never get touched with bare hands. Only things that come into contact with them are gloves and clean aluminum hanging wire.

If you have choosen to clean parts in the house and have been caught by the wife in the kitchen then you are probably in one of two positions. First one is she is mad and kicks you into the garage cause she thinks that is punishment in which case give me a cyber high five. The second case is she now makes you do all the things you should have been doing other then anodizing in which case I did warn you to scope the place out ahead of time. And no…there is not a 3rd option here cause there is no way she is happy.

I buy the De-ox and De-smut in liquid concentrate form and mix it with distilled water.

So now that I am back in the garage I sprits the part down with distilled water from a spray bottle I keep close by. The part now gets dunked into a container filled with aluminum de-oxidizer/de-smut solution. The part gets a 5 minute soaking in the bath at 72 degrees F. Oxidation is known as rust on ferrous metals. In the case of aluminum it too oxidizes however its absence of iron makes the “rust” harder to see. De-oxidizing the part in the solution helps minimize the oxidation layer on the aluminum. Some aluminum contains copper, silicone & magnesium which, when anodized, would produce smut therefore the de-smut solution helps rid the aluminum of these unwanted metals. The de-oxidizing and de-smutting is done at the same time in one chemical solution.

I pour my De-ox and De-smut into a clean container. I store the liquid inside the house therefore it has a temperature of around 72 deg F. I soak the parts at this temperature for 5 minutes.

It is at this point that I deem the part to be free from demons. I do not know if my cleaning process is under kill or overdone however I appear to be achieving success therefore there’s no need for change at this point. The process of prepping the part and cleaning it is by far the most time consuming aspect of the whole anodizing process however it pays off in the end. I often say that is you spend 5 minutes completing a project then it will look like you spent 5 minutes completing the project.

So this completes the first 2 processes of the anodizing procedure. To view the remaining steps you can check out The Full Monty: Part 2

I’ve been trying to get some hood time with my aluminum welding so as to try and improve my skills. I had a request to build a couple of small vacuum canisters that are going to be used for the installation of an aftermarket cruise control system on a couple of Yamaha FJR 1300 motorcycles. It wasn’t a huge job, at first, and I was able to stumble my way through to moderate success.

The only criteria was size. The canister needed to maintain an external dimension of 2 inches diameter by 4.5 inches long. I started with 2” 6061 aluminum round with .125” wall thickness (I know it was a bit heavy however I didn’t have .065”) and chopped off a 4” section. Then I shaved a couple of .75” pieces off of 2” solid 6061. Using the lathe I machined a couple of steps into the end caps to allow for a perfect canister fit.

I fired up the Miller TIG and laid down a couple of beads no problem…so I thought. Once I machined down the welds I installed a 1/8” NPT 1/8” barb brass fitting into the canister, dunked it in a bucket of water and fed 120 psi of air to it. Lots of bubbles, oops. I figured no problem, this is a learning experience. I ran some more beads, machined and performed another leak test. Still bubbles. So I did it 2 more times trying hard not to get frustrated. Performed a 4th leak test, still bubbles, I couldn’t decide if it was time to cry yet.

Obviously the system I was using was not working, I needed to change something. I decided to machine a couple of huge grooves in welds to allow for wider penetration. I had already machined grooves previously however not to an extreme. However it was to a point were the project was garbage if I couldn’t get it sealed. So with a massive valley to lay some aluminum rod into I welded the canister up for a 5th time. Machined it for the 5th time and leak tested it for the 5th time. Perfect! No leaks. Note to self…do not fear the large groove. The aluminum has no problem flowing, penetrating, and filling the gap.

So the canister kind of took on an odd shape due to all the machining however the functionality was not compromised. As an added learning step I decided to anodize the unit to see how the welds would anodize. After polishing the unit and putting it through a cleaning stage I dunked the unit into my anodizing tank for a couple of hours. Upon post anodize inspection it was fairly obvious that the 6061 canister and the aluminum filler wire anodized 2 different colors. I soaked the canister in the orange dye for 15 minutes curious to see if the to aluminum colors would be hidden with dye color. Apparently not, lesson learned. No big deal to fix. I set the canister back up on the lathe and sanded down the poorly colored ends and then polished them up on the buffing wheel.

I can’t say that this is the prettiest thing I have ever made however its main purpose was to try and teach me something and that it did. The best part is that I have to make a second one so I’ll see if I can take my new found knowledge and apply it in hopes of better success.