Paint Booth - Semi-Permanent - Seeking Advice

[MaxThroughput]

Hey All,

My Foundation of the project. I have an old Datsun 240z that I have been restoring for a couple years. I ran out of room in my old apartment garage so I bought a house 2 months ago because I got it for a good price and also because of the 610sq ft garage that came with it.

Flash forward 2 months, I have put up sheetrock on the walls and made an 8ft ceiling, insulation behind everything, ran gas and electrical lines, and installed a 75k btu heater that is doing a nice job of keeping it warm in this Cleveland winter weather. The heater has separated combustion which pulls in outside air, just in case some rogue paint fumes escape the booth.

My Goal is to build a paint booth in the garage that will not only allow me to learn how to paint cars, but to paint them with the highest possible quality given my budget.

My Plan is building a frame for the booth from 1 1/4" pvc pipe with dimensions of 19.5'L x 14.5'W x 7'H. I have already purchased the materials for the frame, it consists of 4 walls and a ceiling. I will be wrapping the frame with plastic, which mil I am uncertain of currently. The booth will be a positive pressure design used for both sanding and painting. I have purchased 18 4' 2 bulb fluorescent fixtures that will be arranged outside of the plastic booth (as they are not explosion proof) and connected to the ceiling electric that I installed with 36 available outlets.

Problems: What is the best way to remove all sanding dust from the booth before painting? What options are there for fans? From what I've read positive pressure designs work best with this setup so that the booth doesn't **** in dust from outside the booth. I will be using intake and exhaust filters to make sure that over spray will not contaminate things outside the garage. Which mil of plastic works best? Will it be necessary to frequently change the plastic or are there more permanent solutions?

My only body work experience to this point is welding sheet metal, body filler work, sanding, and primer. Any advice that can be provided is greatly appreciated. Thanks in advance.

 

[Tdoriot]

Having done a visqueen spray booth, the plastic attracts dust and of course paint gravitates toward the static charge on the plastic. Bottom line, set up a system that allows you to just use new plastic prior to any finish painting. I used spring poles I manufactured similar to the zip wall system. I used 1 mil painters plastic. It comes in 400 foot rolls. I used some 6 mil with a zipper door at one end. Replacing the plastic lets a guy do a better cleanup job. You can't clean plastic and the area at the bottom. Vacuum cleaners grab the plastic, then you have a mess. Mine worked great when I painted a 20' SeaRay and then it's trailer. Replaced the plastic before each finish application phase.

 

[Denwood]

I've done several paint jobs with plastic temp shrouding.

Furnace filters were taped at air exits, and a large floor van in a window (same furnace filters) for positive pressure. Blasting everything with compressed air before shrouding, tack cloths and a wet floor worked well. The heater is always off when painting, and my compressors were kept in the clean air outside the booth. Now they are located outside in a shed, so even better. Be mindful of explosion hazards in the booth! This was my last effort:

 

[Dennis Leigh Henry]

2x on the wet floor idea that Denwood noted. I worked for a painting contractor through high school and college, and their spray booth (basically a garage converted to a spray booth, complete with explosion proof vent fan, and filtered incoming air) was always dirty.. used for all types of painting contractor jobs (brush and roller cleaning, paint pump cleaning, pre job test out, etc. etc.).

If you have the $, invest in a professional exhaust fan with explosion proof motor.

Dennis

 

[buzz4041]

Do not mix dry sanding and painting in the same booth. You will never get the particles out from sanding. Sand somewhere else and paint in the booth.

 

[Whiskyb]

I have to agree with buzz4041.

When I painted my 911 a few years back I built a booth inside my shop as well. I used 2X4's to make walls and ceiling joists. It had a man door and swing doors on the end.

One thing I might advise on is the plastic, as others have mentioned its cheap. Replace it before spraying. I installed mine on the inside wall though as with a positive pressure booth the wall studs prevented it from ballooning

For filters get some good furnace filters between your fan and the booth. Youe exhaust filters will plug easily if you dont have a good gun

Not a fan of water on the floor as it is very easy to have it ruin your paintjob if splashed

There is alot of good information on the Southern polyurethane website. Read there perfect paintjob article. There site has many pro's that offer honest advice. There products are also some of the best out there

 

[sberry]

There is no such thing as a positive pressure paint booth. http://finishingacademy.com/training/aero/aero_mod3/aero_mod3_intro.html

 

[chops101]

Your paint booth should be set up as a clean room only. As suggested, do skimming and sanding somewhere else, even outside under a portable tent...

 

[MaxThroughput]

I don't have the room to build an additional booth in the garage for sanding, and outside is not an option. Is there some kind of material that I can line the booth with that can be hosed clean before painting?

Another issue though is that the material has to be transparent because the lights sit outside the booth. I may have to just do a thorough job of cleaning and changing the plastic between sanding and painting.

 

[Whiskyb]

Replace the plastic, wash the car and floor. Run your filtration while you clean it. This will stir up any (hopefully all of the contaminants) and trap in the filters. A good set of painting coveralls goes a long way in helping with contaminants as well. It can be done you just have to put in the effort

 

[Whiskyb]

I would love something like this http://chameleon.ca/industrial-solutions/spray-painting

 

[MaxThroughput]

I would love something like this http://chameleon.ca/industrial-solutions/spray-painting

Not at that cost! It doesnt look too different from a home made pvc booth, other than the massive filtration and easier collapsibility.

 

[MaxThroughput]

Thinking more about this, theres no reason I have to sand in a booth. I could just move the booth across the garage, and fold up the plastic sides to the ceiling, so its like a canopy. Then I would be sanding on the far side of the garage, where i could lay down a drop plastic dividing the garage to keep the dust somewhat to the one side. Sweeping and removing the dust would be easy then. When i'm ready to paint, i'd just push the pvc booth over to the former sanding area.

 

[sberry]

Read the link I put up. You really cant build a booth without understanding the concept. This is not a clean room, 2 different things. You can see in the last pic the fan is running and drawing the curtains closed. You may not need any framing with decent design.

 

[MaxThroughput]

What do you guys recommend for fluorescent bulbs? I found these which are 90CRI with 2975 mean lumens - https://www.1000bulbs.com/product/56690/F-32L359.html

 

[MaxThroughput]

Sberry - I've read that in the past but forgot about the turbulence theory and paint cloud formation. That's the problem with the internet, there's so much conflicting information and professionals seldom provide advice. Following what that article says, it's best to have more existing air than entering air, so really a draw through system would work and would cut down on the needed fans. Am I right in thinking that I would only need exhaust fans and a filter door?

 

[sberry]

I don't use filters but my air intake is high and from the ceiling and I test run it to clear any loose dust. It forms a down draft and I can paint without sweeping if I want and don't usually bother to d much with the plastic. I originally thought I might have to replace it but its been there 20 years now.
Correct, draw only fans and filters coming in. You want the air opening to the building larger than the opening to the booth, no resistance to air entering the structure and some at the booth to create a draw. Don't worry about turbulence until you try this.
Once you get the idea and the hang of it building a clearing room becomes second nature as does estimating air flow. We were doing something and I was showing the MIL how the fan sound changes and the air came to a stop when we closed the door too tight, its got to have incoming to make it move. Modern spray gun have helped with reducing the air needed to clear a room.
This is definitely a little trial and error thing n a small room but I can tune one in a few minutes. Have painted with 2 or 3 box fans under the garage door and walk door open in some simple setups.
Contrary to popular belief not every car is painted in sterile lab conditions. I know some great body guys with pitiful setups but the work comes out fine.

 

[sberry]

If its clearing well you can put the lamps in the booth. If you need to generate heat you may need to separate the structure in to rooms, you can run stove in the non paint side.

 

[sberry]

The heater has separated combustion which pulls in outside air, just in case some rogue paint fumes escape the booth.

There are no rogue fumes, again, this is a draw booth not a pressured clean room. A clean room under pressure blows air everywhere in the room like blowing up a balloon, a booth is drawing air in every crack.

 

[Whiskyb]

Not at that cost! It doesnt look too different from a home made pvc booth, other than the massive filtration and easier collapsibility.

Oh I agree on the cost of it. What would be neat is to have it come off the front of my garage. When its not in use it could retract into a recess in the building and be completely covered and protected.