Posts Tagged ‘spray booth’

I had been procrastinating finishing the paint booth simply because I had no clear game plan in place. Well my procrastination turned to frustration, depression, and finally anger to the point where I just sucked it up and went at it. People always say nothing good ever comes from getting mad, guess they were wrong. It was my rage and fury that got me to the finish line.

As a quick recap the paint booth frame had been all welded up, the ventilation fan assembly had been built and all the supports that would allow the booth to stand on its own, as well as collapse, had been completed. I managed to get my hands on a 30’ x 40’ tarp which I had planned to use to wrap the booth up like a birthday present. At this point in the project I am still unsure if any of the master plan is actually going to work out in the end. Gotta trek on…

So my rage day came where I went and purchased 175 feet of tarp tape, 15 feet of Velcro, and then came home and set the frame of the booth up. As I struggled to lay out a tarp with a footprint bigger then my entire garage I managed to actually incase the booth. From here on in it was simply a matter of cutting up the tarp as though it was gift wrap. All the seams were sealed with numerous different methods. Tarp tape was used on some, others had 1” x .125” 6061 flat bar sandwiching them, others got Velcro, and the floor was done by folding the tarp into the wall seam. I certainly will not bore you with every seam detail. The project took me a weekend and 5 evenings however in the end I had a 98% sealed booth that was still completely collapsible down to 4 inches thick.

I still had yet to deal with a lighting issue. I needed good light however it could not be installed permanently. I picked up 4 double tube T12 48” florescent light fixtures and rigged them up to see if the illumination would be sufficient. 4 fixtures would do however 6 would be better. So I picked up another 2 fixtures. I strung cables through the tops of the housings to allow for hanging them on hooks. Then using a 50 foot extension cord I wired them up together in 2 sets of 3. The lights all get hung on hooks inside the booth and when it’s time to disassemble it takes approx. 1 minute to unhook them all and hang them on a storage hook in the shop.

I still needed to get an air supply and electrical connection into the booth through the tarp sealed walls. I welded up a support plate that got bolted to the lower corner of the intake filter wall and then configured a stubby extension cord to fit through it along with a permanently mounted compressed air hook up.

So with everything sealed it was time to fire up the ventilation fan, face bitter disappointment and come to terms with the realities of my backyard engineering. Turns out the disappointment is going to have to come back another day cause the booth pressured up fantastic. The walls and ceiling all ballooned out which actually gives me more room inside the booth to move around. There appears to good airflow coming out of the exhaust filter. Now there are minor little spots in the tarp that have a few leaks, I’ll have to wait till I actually spray something to be able to visually see if the leaks are an issue. There is a slight breeze blowing through the center of the booth, it’s not bad and may not affect the spraying at all. Again I will have to wait till I spray to be able to evaluate the full booth performance.

Because of te size of the booth getting good pictures were difficult. The best I have is a video that gives a full tour, you can check it out below.

I measured the RPM of the ventilation fan using a digital tach. The maximum specified speed is rated at 1140 rpm and the way I have it pulleyed down from my 1725 rpm treadmill motor the fan’s actual speed is 1265 rpm. Not too bad, a bit high but until further testing it will have to do.  I suspect I can re-pulley the fan to allow for lower RPM and lower CFMs and still have good pressure within the booth.

Well I can’t stop now, the booth is complete but it still needs to be stored. My current plan is to hang it from the ceiling however I lack a plan at this point. I’ll see what kind of ideas I can grow.



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.

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.