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another paint booth question
21 replies to this topic
Posted 29 August 2008 - 01:13 PM
what size blower motor or how many cfm's do i need to make a smaller version of the paint booth found in the video clip "building a spray booth for painting fish carvings"?Same concept and design just smaller.
Posted 29 August 2008 - 04:56 PM
Don't know about that one, but here's the cheapest and best-performing tabletop spraybooth you can get. I picked up two $12 20" window box fans from the store and stacks of 20x20 furnace filters from my local ACO Hardware for 99 cents each. I put the fans on my bench in a v-shape and put three filters on the intake side of each fan and one on the back side to act as filters. I change the front filter every 50 or so lures, then replace them all about every 500. Works amazingly well and cheap to set up and maintain!
Edited by Downriver Tackle, 29 August 2008 - 04:57 PM.
Posted 30 August 2008 - 06:14 AM
Do you spray solvent based paints or water based paints?
Posted 30 August 2008 - 07:54 AM
Yeah, I forgot about the solvent factor. I spray water-based. I wouldn't recommend spraying solvent through any electrical motor unless it's explosion proof.
Posted 30 August 2008 - 08:12 PM
I built mine with a 1000 cfm squirrel cage blower....made by dayton. You can find them on line. Like I said, I shoot eveything through mine and never a problem.....If you are only going to do water based paints, and want a small version you could probably get by with 400 or 500 cfm.
Posted 30 August 2008 - 09:29 PM
Yeah, we skimped by with non-explosion-proof exhaust fans at a paint factory I worked at. Was fine till just after I left the company. Two weeks later I got to watch the plant burn down on the local news because of those exhaust fans. Remember that a boo-boo like that will probably viod your insurance coverage. Bad part is that an explosion-proof motor is probably around $500-1000
Box fans usually run in the range of 2000-3000 cfm on high. I'm pulling 6400 cfm with the two I have.
Posted 31 August 2008 - 08:54 AM
If you would watch the video, you would understand how it works. It does work.....no fumes, no explosion or fire....there has to be a build up....and it has nothing to do with "skimping by".... It has to do with common sense.....and basic physics.
Edited by rjbass, 31 August 2008 - 08:56 AM.
Posted 31 August 2008 - 09:36 AM
Geez, a bit testy eh? I said WE skimped, not you! I watched the video. I think I've got the physics covered. I totally agree with the concentration of fumes in his explanation, but there's also other factors that can play a role in paint booth fires. Trust me, I've seen dozens of our customers, even some with the safest set-ups, have fires. If you're spraying an aluminum flake paint with alot of acetone, that's the recipe for a fire, even possibly with the set-up in the video. It's just physics. That's an excellent set-up, but I'd probably get a belt driven blower with the motor mounted on the outside. That's the way our explosion-proof booth works.
Most fires or explosions that occur because of non-explosion-proof switches or motors happen when someone turns the a booth on, shop light on, or whatever. Not when the air is flowing, though it does occasionally happen then too. It's very possible to get a build-up of fumes in the booth when it's sitting idle after alot of painting and you could easily surpass the concentration needed for ignition.
I'm not trying to shoot anyone's idea down, just trying to make a safety point. You can make something as safe as possible, but nature will always build a better idiot who won't maintain the equipment or whatever. I'd hate to see someone burn their house down because they had no idea a fire was possible, even remotely. If they read this and know it is possible, then the ball's in their court.
Edited by Downriver Tackle, 31 August 2008 - 09:38 AM.
Posted 31 August 2008 - 09:55 AM
All I was trying to do was help the guy out.....he is not spraying lacquer or any other flammable type paint....but I guess you have to have the last word..... I guess next question I have I will have to ask you....
Posted 31 August 2008 - 11:20 AM
Now I feel better. LOL
Posted 31 August 2008 - 11:31 AM
I guess someone got something warm and yellow instead of cold and white in their cornflakes this morning!!
Edited by castmaster, 31 August 2008 - 11:36 AM.
Posted 31 August 2008 - 05:52 PM
Glad you guys can get along. I've seen other forums go up in smoke from online flaming sessions. Not a pretty thing, for sure.
The fans I use for my dust collector are side mount remote ventilators that I got off a job. The motors are totally isolated from the fan chambers.
It was fun to build the system, but it was a chore, and, in the end, is good for the sawdust, but I wouldn't trust it for anything else.
I'm constantly worried, when I accidentally sand something with iron in it, and the sparks fly, that the sawdust might ignite. I remember all too well the silo explosions that were common when I was a kid. Those were dust explosions, set off by the static electricity generated when dry grain was off loaded from a rail car into a silo.
There is safety equipment to prevent that now, but dust is nothing to take for granted.
Paint solvent fumes can go off like a bomb. It's really important to make sure whatever you use is designed for that use.
Gerryrigged systems, while ingenious, can be dangerous because of what we don't know.
Sorry to be so long winded.
I've just seen some weird things happen when something was supposed to be "totally safe".
Posted 31 August 2008 - 07:10 PM
I,m sure this wouldn,t apply everywhere but around here if you had an accident with a homemade paint booth i,m pretty sure your home insurance would not cover you. They would want to see a UL or CSA sticker on the booth or you could have a home made one inspected by someone like a fire marshal but that would be exspensive and a pain.Using solvent free material,explosion proof motors or belt driven blower motors and insuring your paint has dryed before it even gets near the motor are all steps in the right direction. Of course the ideas, input and critiicism of everyone on the site gives us a place to start then hopefully we can make our own decisions on how we might tackle the problem. I need to build one before winter so hope this topic really takes off .
Posted 31 August 2008 - 09:08 PM
There was a guy around here about 10 years back that was painting cars in his garage on the side and using box fans to vent it. Him and the garage went KABOOM, setting his house on fire and him quite a way though te air. Insurance denied the claim amd I think it's still a vacant lot.
Posted 31 August 2008 - 10:37 PM
The booth used in the video is safe. The ratio of particulates to air never reaches the point of flammability because of the way the booth is constructed; it pulls so much air that the particulates cannot condense enough to reach critical mass.
Posted 01 September 2008 - 09:59 AM
I finally figured out where the video was, and watched it.
That booth is slick as snot!
The guy said he used a 1000cfm furnace blower, and two 4"/4' long spiral ducts so that enough air was being moved to insure that the airstream was diluted far below the explosion level.
He certainly sounds like he has done his homework, and putting that video online makes him responsible if someone copies him and has a problem, so I don't think he was "blowing smoke" when he said it was safe.
While I don't know what the safe level is, his basic point is to have way more air flow than you need just to catch overspray, in order to insure that there's no danger of a solvent buildup.
I'm not sure you can go smaller than what he made and achieve that.
If you're painting water based paints, you can use a couple of box fans, with washable hvac filters in front of them, set at right angles behind your work piece, like Downriver (I think) uses. That will more than catch the overspray. And you can wash the filters in hot water and soap periodically to remove the dried airbrush paint.
If you're using solvent based paints with that setup, there might be a danger that the overspray will build up on the filters and become a problem. At a minimum, you would have to use disposable air filers, and there is still the posibility it could be dangerous, due to the open motor design of the box fan. But it's not a sealed system, so there would probably be enough dilution of the fumes to make it safe. However, it doesn't remove the dangerous-to-breat fumes from the air, so that system, if used with solvent based paints, should be used in an open garage or shop, with the fans near the door blowing out.
In view of the liability issue, that homeowners or renters insurance won't cover a fire that results from a home built system that isn't UL approved, I'd think twice about any sealed system in my basement or garage.
I use two 1000cfm fans in my garage sawdust collector system, because sawdust is heavy, and it takes a lot of air speed to move it up 8' and over 20' he blower/collector location. These fans were designed to move air through a 10" diameter duct, so two of them drawing air from an 8" pipe that reduces down to 4" at each of my locations means a lot higher air speed, which I need.
If I were following his advice to build a paint booth, I'd only use one, and have the two 4' sections of 4" duct to actually allow the suspended paint particle to precipitate out in the duct on the way to the fan. That's the opposite of what I wanted for my dust collector, which needed to keep the sawdust in suspension until it reached the collector, a 30 gallon plastic trash can below my fan/filter assembly.
Edited by mark poulson, 01 September 2008 - 10:02 AM.
Posted 21 March 2012 - 11:47 AM
Is there a link to this "video"? I would like to watch it. Thanks
Posted 23 March 2012 - 10:53 AM
Here is the link....I built one exactly like this and have used it for years and spray everything in it no problems....http://video.google.com/videoplay?docid=3903621338367109945&hl=en#
Posted 23 March 2012 - 02:36 PM
I use both Laquer and waterbased paints with my booth,I built my spray booth directly from the info available from that video and a few other sources. It works flawlessly, If you are standing next to me while spraying Laquer you can not smell any fumes. Of course with this system it is also important to keep your filters cleans as this will drop the ratio of particulates to air. As far as insurance claims you can rest assured that the insurance company will look for any means possible to void you claim if something happens. Especially if you have not modified your policy to accomodate a business venture.