Posts Tagged ‘aluminum welding’

 

The paint booth project progress continues to slowly take place. As usual I continue to be bombarded with side projects which always end up slowing down the main projects. The goal was to have the booth completed before the New Year. FAIL!!!!!! I figured out how to solve that problem, no longer set any goals. There we go…right back on schedule.

The main frame of the booth was previously finished. Before I can start to tarp the entire structure I needed to fabricate the intake air assembly. The plan is to create a pressure booth therefore a fan, and duct work, need to be mounted on the intake side. I had previously calculated out the air needs of the booth. Total booth volume is approximately 936 cubic feet. I want to ensure I can double the air exchange every minute meaning I need to find a fan capable of at least 1900 CFMs. My fan options open up since the fan will not be mounted on the exhaust side and therefore will not be exposed to combustible fumes. Unwanted explosions should not be too much of a factor. Of all the fan and motor assemblies I looked at none of them were perfect for my application. So I decided to build a fan assembly that would suit my specific need.

After flipping through pages of a local appliance parts supply catalog I was able to find a 22” 4 blade aluminum fan with a pitch of 27 degrees that was capable of producing 3640 CFMs of air movement. The horsepower requirement for the fan was rated at .37 horsepower with a max speed of 1420 RPM. I was able to find a surplus 1 horsepower treadmill motor with an RPM of 1750 for $20. This was going to work perfect. Since the rated fan CFM was overkill I would be able to pulley down the fan rotation to get the spec’d RPM. Once the paint booth is completed I will then be able to do further testing. If the CFM movement needs to be tweaked all I will need to do is re-pulley the system.

So I stated the ventilation portion off by welding up a collapsible aluminum frame to support both the fan and the duct work. The frame will fold in flat to the main frame in order to accommodate storage. The idea is that the fan assembly will need to be removed and stored separately from the main frame. With the frame built it was on to the fan assembly. Using some 11 gauge sheet metal a circle was cut and then lined with 1” ring rolled flat bar. With some spare aluminum and a couple of flange mount bearings I was able to fabricate a fan support. The treadmill motor has no case to it as it is designed to mount inside a treadmill assembly. Using some muffler clamps I was able to build a mount for the motor that allowed it to be suspended by its rubber end mounts. Hopefully having the whole assembly rubber mounted will reduce my main frame from rattling apart.

Since I am unsure of what final RPM I will be running I built the mount for the motor out of a length of angle iron. Since different pulley sizes will also impact my V-belt lengths having the extra bit of angle iron will allow me to customize my belt tension adjustment.

I have yet to build a shield for the fan blade. As it sits now I am sure it would do some serious damage to human body parts should something decide to get in its way. Before I finalize the fan assembly the rest of the booth will need to be completed and performance testing will be required.

Next step on the road to completion will involve having to secure a tarp to the main frame assembly. I am dreading this part simply because I am a one man operation that is going to be wrestling a 30’ x 40’ tarp over the skeleton and then having to trim it a fasten it. I suspect a calm demeanor and deep breathes will be involved.

 

I am not sure the blog has reflected, all that well, what my time has really been consumed with lately. I had posted a short bit on a collapsible paint booth that I am in the middle of building. Well the work certainly has not slowed down and, as with most projects, always takes longer then one expects. Anyway…progress continues to take place and a booth is starting to actually take shape out of the pile of aluminum that used to be lying on the garage floor.
The booth has been great practice for improving my aluminum welding skills. I am feeling much more confident with the procedure and feel that I have really been pushed to a whole new level of options when it comes to fabricating.

I have spent a few full day Saturdays working as quickly as I could just to get the main frame up.  The overall dimensions came out to 9 feet wide, 13 feet long, by just under 8 feet high. The idea is that it will collapse small enough, an light enough, to allow for storage on my garage ceiling.

Up until this point I have completed 3 key components. The 2 end frames have been welded up. One of the end frames houses the door which also acts as the exhaust filter and the other end frame has the intake filter incorporated into it. The 2nd key component is the roof section. The roof has been split into 2 sections thereby allowing it to fold down in between the 2 end frames. The end frames and the 2 roof pieces are all held together with hinges. The 3rd key component involves the vertical supports for the center roof sections as well the horizontal floor braces that secure the 2 end frames.

I am not too sure what I can really say about all of this. The pictures are all fairly self explanatory up until this point. I have chosen to make the roof vertical supports and the horizontal floor braces separate from the rest of the structure. I have room for separate storage of these components. With the main frame in a collapsed state the overall thickness is only 4 inches however this will change a bit yet. The entire structure is getting wrapped in a tarp which will only add some bulk to the collapsed unit. I am unsure how to calculate the overall thickness until I can actually test it. Hopefully the unit will still fold as nicely as it does now.

I am to the point were I need to fabricate the fan assembly that will be moving all the air. I have chosen to build my own fan assembly using a 1 hp motor and separate aluminum fan blade driven by a pulley system. Once the fan assembly is mocked up I will jump back onto the frame and incorporate some duct work to help direct the air flow. Stay tuned…there’s more to come.

So I stepped back into the ring for round #2. My first go at the FJR1300 cruise control vacuum canister finished me off with some learned lessons. This time I took what was previously served up and planned on applying it towards total domination upon the canister creation.

For those who have no idea what I am talking about I had previously built an aluminum vacuum reservoir which had presented me with some challenges. The main one being getting all my welds to seal. On my second go I made some modifications mainly to the aluminum pre-weld prep.

I started off with a 4” length by .125” wall 6061 tubing and then sliced up a couple of solid 2” round bar chunks to be used as the canister ends. I machined a step into the ends, like I did on the previous canister, however this time I cut in a fairly deep and wide groove to allow for me to flow some aluminum filler into.

So with the canister prepped, the TIG dialed in, and the challenge accepted I laid down a couple of beads on both ends. Tossed the unit back onto the lathe and machined down the welds. Got a bucket of water and a hose filled with 120 psi of shop air I showed no mercy on the canister as I cranked the pressure into it. Ok…what’s wrong, where are the bubbles? Huh? Hmmm….I guess I can be learned. Looks like overcoming my fear of large weld grooves paid off. The aluminum filler flowed in great and I’ve got a submerged canister with contained pressure to prove it. First run of the welds sealed the unit up 100%. Now what? I had budgeted for issues.

So with success obtained early on I spent the rest of my time prettying the thing up. The ends got chamfered slightly and the whole unit was then polished to a shine. Sweet! Much more satisfying then my first go around. Since the canister is not required for install for a few months yet I opted to hang onto it and set it in front of my computer monitor so that I can stare longingly at it. Some day the two of us will have to part ways but until then I want to make every moment count.

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.

As I have mentioned in the past I suffer from high frustration levels when it comes to putting the finishing touches on projects. Building is one thing but making it look good with a topping of paint, powder coating, or anodizing is whole other set of skills, knowledge, and equipment. In the past I heavily relied on my trusty can of brush on Tremclad and it works well depending on the application however as different projects are completed they require a more professional finish. 

My aluminum welding is getting better

For some time now I have repeatedly said I was going to do something to resolve this issue. Well I figured now is the time. After lots of brainstorming and planning I have begun construction on a collapsible, aluminum framed, positive pressured paint booth. Overall planned dimensions are 9 feet wide by 12 feet long by 8 feet high making an overall square foot area of 108 sq. ft. and a volume of 864 cu. ft.. I have calculated my air exchange CFMs which will have a 1 HP electric motor taking care of the business. The intake and exhaust filter square area has been figured out and there is nothing left to do but build. I have no intention of ever painting a vehicle in the booth therefore the size only needs to accommodate my larger projects.

1/4" crimp nuts used for attaching the filter cage

Since I have been practicing my aluminum welding on scrap it was time to put it to use. The idea is to build the entire structure from light weight aluminum and tarps. The design will allow for me to collapse the entire booth and pivot it up to hang on my garage ceiling for storage.

Installed filter material and weatherstripping

So the beginning stage was tackled and completed. I had started by building the spring loaded man door which is also doubling as my exhaust filter set up. The door is constructed from 1”x1” x.065” 6061 aluminum along with some aluminum 1” and ½” flat bar. The main frame was built and then a grate section was fabricated in order to allow for sandwiching my exhaust filter. I am using a generic 20 ft x 30” roll of furnace filter to handle catching of the overspray. I may need to tweak things as I go.

Main door frame with cage unbolted

For now the aluminum welding is going great. Aluminum is so nice to work with, easy to cut, clean, things seem to go quicker. With all the beads I am running I can see an improvement in my aluminum welding ability.

With the door complete I will be moving onto the end wall construction in which one wall will involve building of the intake filter and ducting.