Big Paint Booth Idea and Final Paint Job

J

JohnL (BlackJeep)

Well-known member
Last year I built a small paint booth vented to the outside in order to paint small parts inside my shop anytime. Here's the original paint booth design http://lappie.org/photos/misc/Paint Booth_files/Paint Booth_frames.htm

As I am finishing my first Cub restoration I am finally painting the biggest parts (fenders and tank). I had planned on having a professional do this part but afer getting a price quote I decided to do it myself. :shock:

After seeing some other paint booth ideas and looking at framing lumber, plastic etc. at the home store, I came up with another idea. It worked REALLY well. The cost was around $100 on sale, let me know what you think.

John

Here's the booth, put up inside my workshop. It is up against the front of my paint booth which is vented outside.

BigBooth1.jpg


Here's the inside of the "big booth" sealed to the front of my "little booth".
BigBooth2.jpg



Here's my finished Cub, just waiting for a tank!
NoTank.jpg


Here's the tank drying in the booth after it's final coat of red. The color doesn't show up too well due to the weird lighting in the booth... :D :D :D
TankDone.jpg
 
John:

Looks pretty darn sharp to me and for only $100.00 you can't go wrong. Nice job on the Cub btw, and the hood/fenders look top notch too :!:

Now show everybody how you built it :idea: :!: :big smile: I hear article... :wink: :D :D
 
John,

Very creative use of very cheap materials. Best of all, I'll bet it has its own storage bag! Need to paint? Get the bag and POOF, instant paint booth!!! 8) 8)

Bill
 
John that does look great :{_}: However depending on what type of paint you used be careful of a fire hazard. Some paints dry by oxidation and will cause filters and possibly your booth to catch fire. Not trying to be Donnie Downer but be careful.
 
Charles,

The exhaust fan is rated around 1100 CFM. When I'm using the little booth I run the damper about 1/4 open and don't open any doors or windows in the shop. It's enough to paint with a spray can inside the small booth with no paint smell and no mask.

For the big booth I left the damper full open and opened a window in the shop wide. The flow of air through the booth is enough to keep the mist moving out fairly quickly, but not so much as to create a dust problem. Of course my furnace runs a bit when I'm sucking in 20 degree air, but it stays around 65 in the booth. Today was around 45 degrees so it was quite pleasant. Overall I'm very happy with the way it performed.

John
 
With a little "creative plastic work" with some 6 mil or 8 mil clear polyethylene on the inside, you could do some major sandblasting. I'm thinking a clear sheet dividing the tent into 1/3 for the blaster and 2/3 for the blasted part. Poke a couple of holes in the divider and tape some long kitchen gloves in the holes. then blast away. If the poly sheet were wide enough you could have a floor, back wall, and ceiling to contain the blasting grit.

Taken one step further, put poly around the outside of the tent with gloves in several places. Then you could blast just about anything.

Rick (the possibilities are staggering!) Dulas
 
Cubguy,

Thanks for the reminder. I realize that these conditions are less than ideal from a safety perspective.

The floor is wet, keeping dust (and overspray) to a minimum. I tried to keep the air flow to a high enough level that (presumably) the mixture was not easily combustible. The furnace is outside of the enclosure in clean air, so flame / heat from it was not an issue. I was careful with lighting, however as you mentioned this was probably the biggest risk.

If I did this a lot I would surely come up with a better (safer) setup. But this worked for me in this circumstance. I encourage everyone to be careful and pay attention to the (valid) safety issues raised by Cubguy.

Thanks
John
 
You are scaring the living hell out of me with that!
As a telephone co supervisor we had our people tes the cable vaults(where they come in from the street) daily and if the door was closed, when it was opened again.
What you have is a death trp waiting to happen.

Please read the below and for further info do a google on lower l8mit of explosion.

Vent that booth to the outside while you are still alive to do it.


The flammable (explosive) range is the range of a gas or vapor concentration that will burn or explode if an ignition source is introduced. Limiting concentrations are commonly called the "Lower Explosive or Flammable Limit" (LEL/LFL) and the "Upper Explosive or Flammable Limit" (UEL/UFL). Below the explosive or flammable limit the mixture is too lean to burn and above the upper explosive or flammable limit is too rich to burn.

The lower and upper explosion concentration limits for some common gases may be found in the table below. Some of the gases are common as fuel.
Fuel Gas "Lower Explosive or Flammable Limit"
(LEL/LFL)
(%) "Upper Explosive or Flammable Limit"
(UEL/UFL)
(%)
Acetaldehyde 4 60
Acetone 2.6 12.8
Acetylene 2.2 85
Ammonia 15 28
Arsine 5.1 78
Benzene 1.3 7.1
Butane 1.8 8.4
Butylene 1.98 9.65
Carbon Disulfide 1.3 50
Carbon Monoxide 12 75
Cyclohexane 1.3 8
Cyclopropane 2.4 10.4
Diethyl Ether 1.9 36
Ethane 3 12.4
Ethylene 2.7 36
Ethyl Alcohol 3.3 19
Ethyl Chloride 3.8 15.4
Fuel Oil No.1 0.7 5
Hydrogen 4 75
Isobutane 1.8 9.6
Isobutene 1.8 9
Isooctane 0.79 5.94
Isopentane 1.32 9.16
Isopropyl Alcohol 2 12
Gasoline 1.4 7.6
Kerosine 0.7 5
Methane 5 15
Methyl Alcohol 6.7 36
Methyl Chloride 10.7 17.4
Methyl Ethyl Ketone 1.8 10
Naphthalene 0.9 5.9
n-Heptane 1.05 6.7
n-Hexane 1.1 7.5
n-Pentene 1.65 7.7
Neopentane 1.38 7.22
Neohexane 1.19 7.58
Pentane 1.5 7.8
Propane 2.1 10.1
Propylene 2.0 11.1
Silane 1.5 98
Styrene 1.1 6.1
Toluene 1.2 7.1
Triptane 1.08 6.69
p-Xylene 1.1 7.0

Note! The limits are for gas, air and oxygen at 20oC and atmospheric pressure.

It is important that the area where flammable gases are stored are well ventilated. When designing the ventilation system, be aware of the specific gravity of the gas. The gas mixture is not homogeneous. A light gas will concentrate along the ceiling. A heavy gas will concentrate along the floor.

Ventilation, natural or mechanical, must be sufficient to limit the concentration of flammable gases or vapors to a maximum level of 25% of their "Lower Explosive or Flammable Limit" (LEL/LFL).

* Minimum ventilation required: 1 cfm/sq.ft.
* Recommended ventilation: 2 cfm/sq.ft or 12 air changes per hour - half the air supplied and exhausted near the ceiling and half the air supplied and exhausted near the floor


The chart didn't copy well this is the link to the origional info.

http://www.engineeringtoolbox.com/explo ... d_423.html
 
John if I understood correctly you have this in a building (garage, barn, workshop) and am venting it to that. The explosion could start there. The airflow should be to the outside. It should not be trapped between buildings or into window wells of adjacent buildings either. Look at the link I posted for the small % of gas compared to % of air to be explosive.
If it were outside and vented like you say I would be partly happy if I knew you were using an explosion proof motor. Vented inside a building the air compressor starting up and shutting down could do it.

I am going to go over your posting on this again to see if I misunderstand and apologize if I do. I know a telephone splicer that was careless in his testing and Al was horribly disfigured. It was Easter Sunday and he was in a hurry to get home. I know of another case where the fumes from a leaking auto gas tank settled into a basement and a spark from a reley operating in the telephone equipment blew up a building.
 
After re reading it now looks as if you are vented outside and I missed it in my fear of what could happen. If my warning saves someone else from not venting outside, my false alarm will be worth it.
 
Bill,

Sorry if I was unclear. This enclosure is attached to my "small" paint booth which vents outside at 1100 CFM, turning over the air more than 1 time per minute inside this enclosure. The workshop surrounding the enclosure is opened up to allow incoming air flow. The mist was never significant for more than a few seconds while painting, similar to painting outside.

While certainly not foolproof or explosion proof, it maintained the fume levels low enough to satisfy me.

I appreciate your concerns regarding safety, you can never be too safe.

Thanks,
John
 
John, I like it very much and will consider doing something along the same line. One question, how do you get the bottom of the booth to lay flat on the floor like yours does?
 
Pete,

There are zippers in all four corners, so you only zip them down to floor level. When I first put it up I thought I would have to lay 2x4s or something around the perimeter to hold the sides down to the ground. But in reality the fit of the fabric around the four posts held it so tightly that the bottoms just layed flat and leaked very little. You have the choice of assembling it with the zippers in the middle of the side walls or in the corners, I picked the right way by accident. :roll:

When I posted this thread, it was to share something that worked well for me, that I felt was within my capabilities. The last thing I want to see is someone being injured copying what I did. So, here's the disclaimer:

There are dangers present any time you are spraying hazardous / flammable material. Please be careful and make sure you have the proper mask, suit and plenty of ventilation. Read all of the instructions with the paint product, including the small print on the can! If you're not 100% sure of your ability to do it safely, don't do it!

There, now I feel better too! :wink: Good luck with your paint job, I hope it turns out well for you.

John
 
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