diy paint booth questions/advise

Were in the process of building a new shop for the hot rods and wanting to build a 14ft x 24ft paint booth in the corner.....looking for advice or links ...do's and dont's....maybe even cfm calculations and air movement specs anything thatll make this project right the first time....thanks in advance

Cut a pit out from the floor and use steal grating for the new floor, providing the arrangement for a down draft booth. You can lay wire screening down over the pit "just below floor level" for filter media to lay on. Then your grate floor lays over that. Typically the perimeter of the pit is outfitted with angle iron (something like 3") in which the grates actually lay in flush with your surrounding floor....
As for CFM,,, you can simply use two fan motors on VFD's. One supplies the incoming filtered fresh air (From outside the booth), and the other handles the exhaust air pulled through the end of the pit. With the VFD's controlling air flow, you can maintain a negative pressure in the booth preventing paint fumes from exiting your paint booth. This is done by running the exhaust a bit faster than the intake air.. A magnehelic differential pressure gauge is typically used in this arrangement to adjust the VFD's....

You might want to explain what a VDF is for some of these guys (not everyone is an electronics guru haha). Variable Frequency Drives are basically programmable motor starters that allow more control over your motors, ramp up-down, rpm's, etc. I'd like to learn more about this paint booth you speak of (sounds great) because I'm not impressed with mine so far and would like to upgrade it a bit. What you described is what I'm wanting to do eventually so if you have more details please share. I will mention the old hanging plastic and wetting the floor trick works very well with the static in the plastic attracting the dirt away from the car (I've seen many top notch paint jobs come from this setup believe it or not).

OK....so now that just shows me that I needed more ideas than I thought of.....I was just gonna install tubing in the pit and didn't think about using steel grating and stones as a filter... That itself should provide a more equal airflow throughout the entire pit.....now I've seen pits cut out under where the car would sit....and I've seen ones with the pits at the sides of the car.. Personally I'd think that if u pulled fumes under the car you'd end up with over spay at bottom of car due to it pulling air beneath the car. Now I've even seen the exhaust framed into the wall at the floor and my thoughts there is its pulling the over spray away from the car and that'd work the beat, but obviously I'm new to this and might be totally wrong......

Not to burst your bubble but now you know why downdraft spraybooths are so expensive! If you're going to use the booth when it's 70 degrees out and all

of the shop doors open that's one thing. If you plan on using the booth when it's 30 degrees out, you have to exhaust the air outside the building and heat

the makeup air. And filter it. And filter the exhaust before you "dump" it outside. You can't exhaust the booth air inside the building with all of the reducer

and fumes from the activators or you'll die real soon! Downdraft in the center is definitely the way to go. No, you won't pull the paint under the car and

deposit it on the underside. (It doesn't happen in the bodyshop) A friend of mine got an old used Binks booth from a stealership that no longer did bodywork

and put it in his shop. Depends on how "Crazy" you want to get. You can put all of the systems together and make it work, but you need to look at someone's

booth and see if you can duplicate everything that's going on. Good luck wiyh the project! It can be done!

The concrete isn't poured yet so at least I have a lil time to research and decide how to do it.. So your saying to have a single pit.. Say 3ft wide and put it in the center of the booth.... Gotta admit it would be easier forming 1 pit instead of 2 on the sides

I'm thinking I've seen downdraft booths that are raised to prevent having to dig pits. Though the booth isn't 'portable' it will allow you to service the underside, and mount the exhaust systems in a convenient place and even break it down and repurpose that space much more easily.