DIY Garage Paint Booth Help/Hints Please

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PUNISHER VETTE

Hi. First post so go easy on me! I'm migrating from the corvette forum for my painting help needs and hoping there are a bunch here willing to offer up advice. I've been using the search function and that's helping but wanted some help on my setup ideas.

I got my lighting for my garage up today(I know not the best for a paint booth lighting but they'll have to do as I bought them on a whim on ebay for super cheap)

I have a crude(don't laugh!) paint drawing of how i'm thinking i'll set up my DIY garage paint booth.
1. The walls will be lined with plastic. The bench will be in line with the door to the house(almost where it is now). 2/4's screwed to bench to create a temporary wall. Red squares are filters...how many and what kind would be nice to know. I just drew in 6 for now but not sure.

2. Large yellow fan pulling air from the house. Air will be directed down the underside of the work bench and out the filters. Yellow fan moves a lot of air so maybe it's overkill? I have all sorts of fans(2xbox(low end), 2xmetal rounds(medium), Yellow(high vol.))

3. I'll be using a HVLP gun but want to catch as much overspray as I can to be a good neighbor. I was planning on the 2 medium metal fans at the window with a box of filters surrounding them. Since i'll be using 15+ filters possibly so i'm hoping I can use somewhat cheaper ones and not Hypo allergenic for $40ea:greedy_dollars:.




-any tips/advice on my setup?
-Kind of filters that are good at collecting over spray and/or good at filtering at the inlet? $5/ea seems kinda like a good price I wouldn't mind paying.. Unless those kind are useless and I need to be educated.
-What do people do with their garage doors? If I build a booth do I make the garage door plastic wall removable so I can block sand with the door up and get the dust out normally and not via the window? Or once I start painting... booth stays up? Not sure how to get the dust out other than washing a bunch.
-I also have a mister for the porch... I could easily put that outside the two windows and have running if anyone thinks it'll help with overspray escaping at all.

Anyway... That's all I can think of for now. Thanks in advance!

EDIT: The picture is actually HUGE... you just have to click on it, then click the + magnifying glass to get the real size of it to see my fancy drawings :D
 
I wouldn't want to open any door to the house, I'd suggest to seal it well with duct tape or something to keep any back flow or other odors out of the house. If you are using iso laden hardeners, that's the last thing you want in your house for the family to breathe. I would suggest using the walk through door as your air intake, filtered of course. Then the suction out the other two windows as you show. Seal off the garage door as best you can. Any garage environment will have dust issues to contend with, sometimes just covering with plastic sheet (work bench) is your best option
 
MP&C;39541 said:
I wouldn't want to open any door to the house, I'd suggest to seal it well with duct tape or something to keep any back flow or other odors out of the house. If you are using iso laden hardeners, that's the last thing you want in your house for the family to breathe. I would suggest using the walk through door as your air intake, filtered of course. Then the suction out the other two windows as you show. Seal off the garage door as best you can. Any garage environment will have dust issues to contend with, sometimes just covering with plastic sheet (work bench) is your best option
Click to expand...

Thanks! I figured with as much filters and flow out the windows pulling from the house wouldn't have any back flow but i could be wrong. I also fear bugs and the cold... which is why I was hoping to pull from the house. It's going to get cold on me early this year i'm afraid... I might have to pre heat the garage then pull heated air from the house to get it warm enough...or else i'm stuck till spring. :(
 
I'd say to get your "booth" set up during the week if forecast shows a hot weekend. In fall/winter I can have my shop heated to 75, turn on the booth fan, go in and spray for five minutes and come out to 65 degrees. It will suck the heat right out. So when painting in cold months I set up a torpedo heater aimed at the air inlet (just above floor level) on my air handler in the shop, turn off heat on thermostat and turn fan to constant on, relying on torpedo heater to supply the heat. This circulates the heat throughout the building and keeps up with the booth pulling it out, even in freezing weather. But my air handler and all the ductwork give me a nice buffer to keep the heater's output safely away from anything flammable within the booth. You don't seem to have that option in yours, and that style heater isn't the best to have in your garage while spraying.. So I'd pray for warm weekends..
 
Another thing that will happen is the other tools and cabinets will end up coated with over spray. The factory booths have huge CFM fans moving air and most garage booths come nowhere near the amount of air flow needed to pull the cloud all the way out.
 
I think any heater that involves flame is an accident waiting to happen if used inside the spray environment. Perhaps a heater could be set up outside your "intake door" to provide heated air coming in. Just need it to be far enough away that the filters don't burn up.. ;) Strategic placement could act as a thermostat. Try it out with fans running, if it's getting too hot, move heater away from filter area more. Too cold, move it closer...
 
Yeah. I wouldn't put the heater in the booth. That's why I was hoping to pull warm air from the house or use my heater in the other section of the garage. I don't think it would keep up but I can turn the fans off once the booth has aired out a little and get the temp back up.

I guess when I get closer to painting I'll worry about the heat part. For now I was hoping to get info on how fancy a filters I needed and if large yellow inlet, 2 metal medium outlets would be a good combo for air flow. I know the air goes low to high...but I gotta deal with what I have.

Also if anyone has pointers on rigging a temp wall to secure the plastic too. Staple it to 2x4? Pvp? Just duct tape to the ceiling or will that not hold well enough? The less wood I use the easier for me.
 
Build a cheap wall with 2x3 its just gotta stand up and hold plastic and 2x3 8' are only like $3
 
best inlet filters are the ones that are tackified. They have plenty of sources on ebay, some are sold in accordian type tied together that would probably fill up a door way, or the space you can lift that overhead door up and put them along the bottom. You will also see paper or fiberglass filters. They dont look like much but catch alot of overspray. You dont want anything too easy to plug before the fans because then you wont get any draw and the last thing you want is to start moving filters around when the paint is wet.

Your best spray booths are going to make up the air you are removing, so if you are putting a fan in the house doorway to bring heat in, make it equal to the cfm's the fans are pulling out the windows.
 
Air intake from the house has to come from somewhere, and if the house is sealed up tight when the weather turns, sometimes the negative pressure is enough to pull furnace gases in through the flue. There has to be an air intake in the house in the form of an open window, and that might make the natives a bit restless.
 
Thanks guys. It's just me in the house so no need to worry about others complaining about a window open. I'll definitely keep a window open upstairs to equalize the pressure in the house. Hopefully by the time it gets downstairs the furnace has had a chance to heat the air some.

So I assume most leave the booth up till they're done? I'll be spraying primer, blocking, spraying.... It'll be weeks of sanding I think that I worry will create so much dust...not sure how well I can get the booth clean again and ready for color/clear.

I'm still unsure what filters to get. I don't like the idea of the cheap fiberglass filters as I can't believe they do a very good job as I can see through them lol. BUT I also don't really want to spend $50 for tackified filters... Does MERV rating matter? should I look for a higher MERV that might help stop smoke and stuff like that? Or will the cheapest accordion ones work equally as well for paint fumes? although clogging doesn't sound good either.
 
I've been getting the tacky (inlet) filters from McMaster (snug fits):

http://www.mcmaster.com/#standard-air-filters/=tsidjy

....and the particulate filter by the roll (polyester).


The inlet's come with an internal frame to help hold the shape. My outlet (plenum) area of my booth has external wire "cages" in each 20x20 hole to hold the shape of the material, so the roll stock works fine.
 
PUNISHER VETTE;39772 said:
Thanks guys. It's just me in the house so no need to worry about others complaining about a window open. I'll definitely keep a window open upstairs to equalize the pressure in the house. Hopefully by the time it gets downstairs the furnace has had a chance to heat the air some.

So I assume most leave the booth up till they're done? I'll be spraying primer, blocking, spraying.... It'll be weeks of sanding I think that I worry will create so much dust...not sure how well I can get the booth clean again and ready for color/clear.

I'm still unsure what filters to get. I don't like the idea of the cheap fiberglass filters as I can't believe they do a very good job as I can see through them lol. BUT I also don't really want to spend $50 for tackified filters... Does MERV rating matter? should I look for a higher MERV that might help stop smoke and stuff like that? Or will the cheapest accordion ones work equally as well for paint fumes? although clogging doesn't sound good either.
Click to expand...

The cheap fiberglass filters are catching the paint. They are wide open to keep the air flow up and continue to catch overspray. The solvent smell is going to get outside unless you add a charcoal of some type after the cheapo fiberglass. So catch the paint first, then catch the smell if that concerns you with a more expensive filter. Just try to keep that expensive one clean.

McMaster also sells the tackifier spray http://www.mcmaster.com/#air-filter-tackifiers/=tsiz9u
2071K3

You can get cheaper filters and spray it on them. Home depot actually have green fiberglass filters, they have a bent cardboard frame I think they were about .70 each, they were in packs of 3 or 6.

As far as dust, prime everything that is bare, inside and out and water sand everything, that will keep the immediate dust down (and out of your filters). You put some dish soap in the water to lubricate the paper, keep it from clogging and also making the water not evaporate as quickly. We had been spraying down the booth, but what I started doing was spraying down the floor and then mopping it up to pickup the dust.. Water is your best friend to keep dust down. (Well, starting with well sealed concrete is your real best friend)
 
So I spend the past few days putting up plastic for the DIY booth.

Started it up for the first time today and it was a huge failure. :disturbed:
I couldn't feel hardly any air coming through the filters. and the wall just started to catch wind like a sail until they eventually caved the polls(which are pretty strong)

1. I used .7mil plastic with the quick polls I bought...which I like the idea of. I'm thinking the plastic I bought is far too thin allowing it to stretch. The plastic was stretching till the polls couldn't hold any longer.

2. I'm going to have to tape the plastic to the ceiling in the areas the polls aren't I'm thinking. As I don't want to buy more polls and they can only do so much.

3. 6 filters not enough for 2 fans? Even on the lowest setting of the two and the massive leaks on the top of the plastic the walls still bowed like crazy.

Any ideas? Other than building wooden frames.(not my house and I don't want something that permanent to deal with.

Pic: The top when I started the fans was taught and no gap. Now stretched out badly and of no use.


The two fans. Plastic on the permanent walls is a little to prevent dust, a little to help hold heat, and a little to protect things.

Hint...I took the pictures after I closed the windows for the night. I'm not that dumb lol.
 
I'm almost positive the problem is with my filters.

Why would they be so restrictive? I put two box fans behind them to try and help force air through and still couldn't feel much air coming through.
They weren't the cheapest... any way I can test why they suck so much?

1 round fan on low setting and the negative pressure builds... Not even close to 2 fans on higher settings :(
 
You should calculate your air flow so that the total amount of air contained in your booth changes at least once every 2 minutes. This is why commercial booths have such large CFM fans.
Filters have a Flow Rate per sq. in. if I remember correctly. Use that to determine the number of exhaust filters you need to handle the air flow. If you are making a Positive Pressure booth your intake filter bank needs slightly more area than your exhaust filter bank. (This will push your plastic walls out rather than pull them in.)
 
I have a little over 2000sq/f of space boxed off if my calculations are correct.

The Patton fans are VERY powerful. I can't find any specific CMF ratings on them but similar ones I read are around 3000+CFM on high.

This photo was only 1 round fan...on LOW...which is only 1500CFM i'm guessing. AND i put two box fans on the other side of the filters to try and help force air in. I just can't believe how LITTLE air these filters are allowing through. I'm tempted to take them back to HD as I have no use for them now.




I can't find any data on how much CFM should be flowing through each of the 6 filters. But I can barely feel a breeze when I had the fans behind them. amazing how little they allow through it seems.
 
According to my research... in general filters are rated at or around 300FPM. 6 filters x their square area used(14x20=2sqf each)=12 sqf x 300= able to handle 3600 CFM of air flow. which is at least one of the fans on high.

or another way. 1.25sqf of filter area per 400 CFM. So I have 12sqf filter area=3800cfm flow capacity.

So the fact that it can't even handle one fan on low then something isn't working right. Cheap HD filters maybe??
 
I saved a lot of documentation on filter sizing and booth airflow when I did my research. The calculations I have say a 12 sq. ft. filter bank would only be rated at 1200 FPM.
So if you have a 10' x 20' x 10' high booth that would equal 2000 cubic feet of air. The 2000 would be divided by the airflow requirement of 100 FPM to give you the filter bank size.
2000 divided by 100 would require a 20 sq.ft. filter bank to adequately handle the airflow.
Of course these figures are based on automotive paint filters so as you say the HD ones might have a different flow rate.

Now for a temporary booth I doubt I would get overly worried about it. You mainly want to pull the cloud out as quickly as you can. My booth takes about 2 1/2 minutes and that's mainly due to turbulence caused by the square corners and using the garage door as my exhaust portal.
 
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