Paint Booth Questions

[red vette mike]

I have a room in my new garage additon (31x54) that is 14'x25'. I plan to do a small amount of spray painting in here. I am going to buy a non-spark exhaust fan and will have the air source on one end of the room and the exhaust on the other. The room is 12' tall. Is there some formular as regards how much filter space and material I should have and what capacity exhaust fan I should put in? Should the fan be mounted on the floor or up higher or does that not matter? I have the correct I/R air lines run and will have a deVilbis desicant dryer. Compressor is I/R 7.5hp 80 gallon. The lights are not explosion proof 9 (8 4 gang flourescents). Should the exhaust also be run through a filtering process? I am in the country and will do work only on my own vehicles. Will use Sikkens/Lesanol paints.
Thanks, Mike

 

[sharpshooter]

It would be a nice if you could build a grate type floor with filters in it and run the exhuast to where it would create the overspray to go downward

 

[red vette mike]

It would be a nice if you could build a grate type floor with filters in it and run the exhuast to where it would create the overspray to go downward

That would be cool. However, I am now out of $ and I need to get this room going. I will have to work with what I have (for right now.) I suppose you come back ahd raise the floor some to have a downdraft type of operation.
Thanks.

 

[Bisqwik]

Mike, I have a wing I built on my shop under my lean. It is a 15x25 with a 12x12 over head door. My shop has heat. The room is off one of the sidewalls of my shop that has 16' walls. I have not built the booth inside the wing yet but I need to bad. What I am going to do is bring filtered heated air in from the shop. (I try to do most of my painting when it cools off that way it is not dripping wet out side. You are in MS you know what I am getting at.) I will build a drop ceiling in the booth with a crawl space on top. I will have a 10' foot roof in the booth with doors that swing out. It would be hard to seal the overhead
Door. I can also have my lights out of the booth in the space overhead in and in the 45's on the upper part of the wall. I will build boxes with glass lens for the lights to shine through. Will also build boxes on the sidewalls for the lights and seal them up so the vapors will stay out. I will use two belt driven fans in the lower back corners. I will have filters on the fan on the way out too. I put a drain in the floor when I built it for water. The walls a ceiling will be sheetrock. When the overhead door is all the way up I can gain access to the craw above the booth. I have a walk in door that comes from my workshop. In some of I know this is going to work well I just need too get time to make it happen. If you go look at my pic on Webshots I painted my ski boat just in my shop were I did the glasswork. Water on the floor and my big vent fan cut on when it got too cloudy.
John

 

[chaingang]

I have painted several cars in my old shop and find it works best to blow the air into the booth so that you are pressurising the room and then filter all exhaust exiting the booth with several vents. This way you can filter all incoming air. If you try to draw air out of the booth with the fan you will end up pulling dust, bugs etc... through every little crack. Trust me you can't get everything sealed up tight. One controlled air inlet is better than door cracks, light fixtures and all the spots you can't see. I would want to have enough air flow to do a complete air change every couple of minutes. This would be the cubic feet of the room divided by the fan cfm. You can always make a diffuser if you want to slow/direct airflow.

 

[Satatic]

I have painted several cars in my old shop and find it works best to blow the air into the booth so that you are pressurising the room and then filter all exhaust exiting the booth with several vents. This way you can filter all incoming air. If you try to draw air out of the booth with the fan you will end up pulling dust, bugs etc... through every little crack. Trust me you can't get everything sealed up tight. One controlled air inlet is better than door cracks, light fixtures and all the spots you can't see. I would want to have enough air flow to do a complete air change every couple of minutes. This would be the cubic feet of the room divided by the fan cfm. You can always make a diffuser if you want to slow/direct airflow.

And then yuo wouldn't have to worry about paying for a fan that has explosion proof in the title too.

 

[sberry]

You draw air thru a booth, a booth needs negative pressure. http://dodconf.swri.org/2003Papers/Thelen.pdf This link will help with design, I have made some very good makeshift booths that clear very well in small garages, my own rolls up overhead and out of the way.

 

[red vette mike]

You draw air thru a booth, a booth needs negative pressure. http://dodconf.swri.org/2003Papers/Thelen.pdf This link will help with design, I have made some very good makeshift booths that clear very well in small garages, my own rolls up overhead and out of the way.

SBerry: Thanks. That is very informative.
Mike

 

[Pops]

Man, I have to get organized and make sure I have all this great informaion available when I take the paint booth step.

J.

 

[Down Under Bloke]

sberry27, I would like to see your roll up make shift paint booth, have you got any pictures of it.

Has anyone else had experience with temporary pain booths and have pictures. I'm thinking of getting one of those cheap chiwanese tent garages and using an extraction fan.

 

[383IROC]

I made my own explosion proof fan for my low budget paint booth build. The motor will mount up to the belt sticking out of the 4''x4'' tube... totally out of the air stream.

 

[383IROC]

Should the fan be mounted on the floor or up higher or does that not matter?

The intake for the exhaust fan should be mounted down low because solvent fumes will settle to the bottum of the booth in between cycleing the fan on and off.

Should the exhaust also be run through a filtering process?

If your exhaust is strong enough to pull through another set of filters why not. It is better for the enviroment and they will help keep stuff outside of your shop and the fan and duct work free from overspray.

 

[Uncle Buck]

That is a great looking fan. I do not mean to be critical, but I can think of no way that your fan would meet the definition of explosion proof. Generally speaking, the criteria for explosion proof anything ( regarding electrical appliances) equates to alot of $$. Most paint booths have light fixtures mounted to the outside of the booth, and illuminate through tempered glass installed in the walls or ceiling, keeping all of the electrical components located outside the booth, likewise the light switch would be located outside of the booth etc.. etc.. even something like a radio setting up high on the wall on a shelf in an actual paint booth would be a no no. If you intend to totally seal off the opening surrounding the belt and sheave, so there is no air shared between the booth and where the belt and sheave meet at the motor end, then mount the motor outside of the booth, you would be satisfying the safety criteria pertinent to the issue. Everything as I described it only applies to an actual solid walls booth. If the idea is to strap a motor to the top of your fan housing and have it setting on the floor or even mounted to the ceiling, you in no way have explosion proof anything. Remove the motor from the booth and seal the airway around the belt, then you have something! It is still a great looking fan, just not explosionproof.

 

[Bisqwik]

I like the fan. It looks to me that the tubing has a bottom in it. That is a flange bearing on the front of the tubing. It even appears to have sealant around it. So my guess would be the belt and pulley are totally enclosed. That means they are out of the air stream. It looks good two thumbs up.
The booth fans I have seen have aluminum fan blades so you would not have to worry about sparking. Your do look aluminum. Again nice job.
John

 

[383IROC]

hholmberg: The fan will be mounted outside of the booth.

Bisqwik: The fan blades are aluminium. They are from an industrial air conditioner. I had to take 3'' of each blade to get them
to fit and they came out pretty well balanced spinning at 1750rpm.