Technical Home Made Paint Booth

I have seen a ton of threads on here about home made paint booths and I have tried to study them to come up the best plan suited for me and my budget. There is a ton of back and forth about what is necessary and I am not sure what is opinion or fact but I want to run this by everyone. I live in South East Iowa and I am trying to get a booth going so that I can prime my car this winter so in the spring I can hopefully get it painted in the same booth I am building. I am planning on shooting SPI epoxy and two things have me really worried, temperature and ventilation so I don't go up like a roman candle. My shop is a 20 by 20 which leaves space to be desired but hey, its what I got. My plan is to build a 2x4 structure inside my shop with thick plastic and a zip up door way. The shop is insulate all be it not the greatest. I have a plethora of heaters but the main one in the shop is new to me this year a 35,000 BTU 220 heater. I also have my diesel/kerosene torpedo heater that I was told to stay away from using while painting, and I have a small propane heater I was going to use to help heat the shop but shut off while painting. I know I need to keep the metal 65 or preferably 70 degrees. Do you think a set up like that I came up with would work for this? Will cycling the air through the shop take enough of the fumes out if the the shop is still sealed itself? I don't really have the cash for explosion proof fans so I figured if the fans are on the outside of the booth spraying in it wouldn't be a issue. The lighting will also all be on the outside.

 

Sounds like a solid plan. Sounds like you've been doing a lot of research. Sounds like you're taking extra steps to be safe and that's really the most important part.

Taking explosion proof fans into account, the only thing I can think of is it seems like you'd get better performance if the fans were pulling rather than pushing the air through the booth.

Please keep us informed and share pics. You and I have the same size shop and I'm curious to see how you're going to erect this thing in there. I've got a tailgate to paint and would like to do it right this time, in the proper climate, and to not have to wetsand out a butt ton of dirt.

Subscribed.

 

I did something similar to this when I painted my 53, but I used two fans blowing in, and 1 large box fan pulling out (all fans through filters). For safety reasons I grounded the plastic sheet as air flow across plastic can generate static electricity.

 

I'm an engineer, not a painter, but like the idea of pressurizing the booth by blowing filtered air into it instead of sucking fumes out:

• The positive pressure will help keep dust out.
• The spark/fume explosion risk is eliminated.

I'd recommend making the filters easy to remove/replace. They'll get dirty.

 

That logic is sound! See there? I learned something today... and my wife didn't even have to beat it into me like everything else I've learned lately.

 

Your plan sounds ok, but why not maximize your interior space and just plastic the interior walls. I do this by using push pins and hanging plastic from ceiling along top of walls to floor. My ceiling is OSB.
Its easily removable, and cheap. I buy rolls of automotive paint plastic from parts store. Comes in 100 plus foot rolls, comes in different width's and again is reasonably priced. It is made to cover a car when painting and has a special coating on one side if used on a car.
When I'm finished, I can just pull the plastic down from ceiling and throw away. I rehang new when it gets dirty or when ready to spray color.
I also would not pressurize my homemade booth, as I don't think the fumes and overspray will be removed quickly enough and will build up incredibly bad.
I use a fresh air respirator with pump setting outside booth. If you use only a filter respirator, you need clean air for it to filter, it won't work well if it's 100% paint fumes in there.
I am a painter and have been doing it for 40 years. This works for me.

 

Ruined my first painting attempt when I accidentally hit the plastic sheeting with compressed
air, dried paint everywhere. Went to my local Goodwill store and bought a bunch of used
sheets to line the booth. Overspray sticks to them and as a bonus, they diffuse the lights
beautifully. Plus I had giant Disney characters to keep me company.

 

Thanks for your input! What kind of fan(s) and filter(s) do you use?

 

The reason I'm thinking two fans pushing in is to keep the booth pressurized to keep dust out as well as then the fan isn't sucking in the fumes as bad and increasing the chance of and explosion. I'm hoping it works but I don't know, I wish I still had access to the body shop I used to work at LOL.

What did you use to ground it and how?

My plan is to use a HVAC air filter bracket to hold the filters.

 

Only reason I was thinking a booth was to try and filter the air out and not fill the entire shop with over spray and fumes. If I was to use the whole shop I'm not sure how I'd filter the air since it'll be winter and I can't open the doors.

 

I was in the body shop for over 40 years and have heard of and seen the results of fires in the exhaust fan, buy a good sealed fan! Using a cheap Chinese box fan is nuts, you can filter the solids but not the fumes and that’s what will get you…

 

Weather pushed or pulled by the fans the air in the booth area must be replaced with fresh air at the same cubic foot per minute rate. Visible overspray should be minimal while the trigger is pulled and virtually disappears once you have released the trigger. Overspray and lack of air flow drawing the solvents off the surface, is the death of a paint job, at 20 x20 x8 high you have 3200 cubic feet of air that must be replaced that needs replaced by the minute
If it looks like a three-wing circus it propyl is,

 

^^^^ That is a very valid point, and your sealed 20 x 20 shop will fill up with fumes quickly. With only 20 x 20 available, what size would the booth be, and what size is the car? You need at least 3 feet of distance from the car to the booth walls to allow room for the air hose and airborne paint droplets to drop out. My booth was 12 x 24 x 8 (I pm'd you a picture). Using your drawing, if it was me I would exhaust the fumes outside via the drive in door.

 

I acknowledge and understand that it would be better to bring in fresh air from outside, but when it is 10 degrees outside I can't see how that is a good idea either. My whole plan in trying to make a booth was to not loose my heat, for all I care I'll just wet the floor down and shoot the car but then there is no way to vent the shop if it is cold outside.

 

As far as the three wing circus goes some of us don't have professional booths or access to one. I'm just trying to figure out a way to prime my mercury this winter. If my plan is a bad idea that is fine, I'll just wait till spring I guess but then that is an entire winter of dead time which sucks. I do not plan on painting the car this winter, just priming it. I will prime parts separately for the most part not the entire car at one time other than when I have to actually do the shell. I'll probably just plastic over stuff I don't want over spray on and shoot it and see how it goes and scrap the booth idea. thank you

 

I am not sure where the 3-ring circus comment came from. doesn't even sound like something I would say? I must be losing it. lol Did not men to be derogatory. But what I am tiring to say is if you do not exhaust the fumes and replace with fresh air you will be creating a BOMB of disastrous and possibly fatal proportions. Paint fumes are no different than a natural gas leak. A number of years ago there was a body shop with a Spray booth. Evidently the owner was trying to save heat and was painting a car in the booth without the fans running. Don't know what caused the spark because he didn't live t tell anybody. I am not trying to be an ass but after 50 years of being in and around they Bodyshop industry I know the dangers and what works and what doesn't. And after owning a shop with a downdraft booth with a million btu air make up system I know the pain of sucking heat out of the shop/ Just be careful and be safe. Larry

 

Is your outside door a roll up or swinging? If it's a roll up, you could make a false door out of plywood with a hole for your exhaust fan, then close the door down on it. That would get the fumes out, but you would still need a window to pull fresh air in, and it would be cold unless you had some way of heating it like one of those window AC units with electric heat.

 

You must exhaust the fumes and have a FRESH air source. Concentrated fumes can take you out. You can't recirculate the dirty air through the fans, especially with a heater going in there. BOOM! Just wait til it warms up.

 

don't get too carried away--face it, you're not a pro doing this everyday so do you really need all the prep necessary for everyday use? Key thing is ventilation, not a hurricane blast of air. Good lighting ( a must), sensible paint temperatures-ambient and material, and quality spray equipment (gun, compressor, etc.) plus your safety with a certified respirator, are all necessary. The paints nowadays lend themselves well to color sanding and buff outs of small particles and trash, unlike the older paints. Start small, correct, do again and eventually you'll be where you want for the full job. Oh, this stuff called sandpaper is fantastic for boo-boos.

 

After looking at your drawing.............
My suggestion would be to make a portable wall in two sections that can be slid into place and stood up on the left side of the building. A few deck screws to hold the sections to each other and to the ceiling. (assuming you have a ceiling). The wall would isolate your compressor and your heater though you could make provision for air from the heater to blow into the booth. That may also blow dirt. In the wall I would permanently mount a few used flourescent lights that can be plugged in with an extension cord to the left wall. Then cover the wall with old sheets or plastic sheet.
Make one place on the wall thats open so you can walk to the air compressor area. Put a plastic drape over it, so you can move in and out of the booth. Look on Facebook marketplace and look for a used stainless steel table. You can mix your paint on the table. Probably $100 for a small flat one, but they clean easily and are easy to resell.

On the right hand wall I would simply temporarily mount plastic sheeting and a couple of used 4 bulb flourescent lights. You can make stands for the lights so you can just stand them up and reuse them any time, or temporary wall mounts that you just slip them onto some screws that you leave in place permanently.

For the back wall, I put a small barrel (drum) thru the lower part of the wall in my booth. I bought some sand blasting media and it came in small drums about 2 ft tall and maybe 16" diameter. The small drums like grease used to come in work well if you can find one. Anyway.....stick the drum thru the wall so that the end with the removable lid just sticks inside your building. Then the lid can be removed when painting and closed up when done. On the outside, I bought an old squirrel cage blower. Look for one that has an external mounted motor rather than the ones with the motor mounted inside the cage. That keeps the electric motor away from paint fumes. Make some kind of adapter to hook the barrel to the squirrel cage. I put an off/on switch inside my booth. You have to cut the bottom out of the solid end of the drum.

You can preheat your booth, but when you start drawing outside air into it, the heat will disappear. It will however help keep the booth warm between painting coats and drying later when done.

Remove the temp wall when done and put the lid on the drum and your shop is back to normal use.

 

Check out the paint booth I built in my garage to paint my RPU.

https://www.jalopyjournal.com/forum...-the-driveway-or-garage-thread.943236/page-21

Scroll down the page and you’ll see lots of pictures.

 

I painted a car in this this summer…

 

When I was teaching auto mechanics we had one that we made out of PVC tubing and visqueen. About 100 bucks total then. That was before all of these portable canvas carports showed up though. If I had a building big enough I'd just set that portable carport frame I have that I paid 35 bucks for up, cover it with visqueen and use a swap cooler fan or old furnace fan that had a belt drive for an exaust fan with a box around part of it to be the air intake. If it is like the one I have out here it might be more air flow than you want but it would be cheap if you scrounge a bit.

 

A company I used to work for had a chamber around the equipment to keep it at a set temp (19-21degrees C). The ac unit was a “super cooler” and was around 10-12 C. The cold flow was heated up through an electric heater unit to take the cold air and (depending on set point) maintain is at the before mentioned temps with .1 degrees C.
Now I don’t think you need such an elaborate PID controlled heater, but if you blew the incoming air through a set of heater elements, it may work the same? I/e heat the flow from the cold fresh air.

 

I have a large overhead heater that I purchased from a guy because he couldn't get it to do a good job keeping his shop warm. It was a good size natural gas unit and almost new. It did a mediorce job warming my 40x60 shop.....
I noticed that the air coming from it wasn't very hot. I decided that the air blowing thru it was cooling the radiating fins too much. Installed a smaller pulley to slow the air down and noticed an immediate improvement in its ability to warm my shop. Could stand in front of it and feel the hotter air coming out.
The point is that it takes a lot of exhaust to draw paint and fumes from a paint shop, so unless a heater can keep up with that much exhaust flow.....it may be difficult to get any heat especially if the temperature outside is very cold. The ducting for professional booths is usually pretty large stuff.

I'd just pick a day when temps are near 70 and warm the building and car . Then turn the heater off and paint. Then turn the heater on again between coats and after the finish coat......if needed. You mentioned painting in 10 degree weather...........I wouldn't even think about trying that.

 

one bad 51 Merc ! I am not sure where the 3-ring circus comment came from. doesn't even sound like something I would say? I must be losing it. lol Did not men to be derogatory. But what I am tiring to say is if you do not exhaust the fumes and replace with fresh air you will be creating a BOMB of disastrous and possibly fatal proportions. Paint fumes are no different than a natural gas leak. A number of years ago there was a body shop with a Spray booth. Evidently the owner was trying to save heat and was painting a car in the booth without the fans running. Don't know what caused the spark because he didn't live t tell anybody. I am not trying to be an ass but after 50 years of being in and around they Body shop industry I know the dangers and what works and what doesn't. And after owning a shop with a downdraft booth with a million btu air make up system I know the pain of sucking heat out of the shop/ Just be careful and be safe. Larry

You are dead on with this comment no pun intended , but with this said , a person could become a statistic.
Vic

 

Be safe yes, but you’re not building a rocket ship here. You need to be able to have air moving through the booth, wear the right type of mask, etc.

We’ve painted a few cars in the booth I set up to do my Avatar car and it works surprisingly well. The booth takes up about 1/6 of my shop, which is heated with a propane furnace about 20 feet away. I painted my car when it was 18 degrees outside and about 70 inside. If you’re worried about the hazard from your heater maybe you could turn it off while painting. I used two box fans for incoming air and one for outgoing, but after using it a bit I find the single exhaust fan is usually sufficient - especially if I have one inflow fan on low. The exhaust fan is pulling from outside, the inflow fan(s) push from outside (shop interior) into the booth. I made a short section to hold the exhaust filters (cheap household furnace filters) that the garage door closes on top of.

There are other threads about DIY booths you might look at - some are really crafty.


John

 

Well, You guys do what you are going to do. Just keep in mind that once you start spraying, you and those plastic walls will be coated in flammable material. Sounds like most of you have never seen the results of a flash fire, Hope you never do. Larry

 

Where are you in Southeast Iowa? I have a 36" explosion proof fan sitting in my storage container that I have used in the past. Not pretty but gets the job done.

 

Epoxy, shoot it in stages. Warm up the shop - warm up the paint - Air the place out in between. It doesnt take that long to clean a gun, doesn't have to be a marathon spray session.

Bodywork and block sanding always take longer than expected, you'll be shooting paint next spring or summer anyway. then dust is your concern, not how to run the furnace.

I like the booth plan, if you build it, post plenty of pics.