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Hello,

I’ve spent the last couple days eye guzzling the archives looking at all the home spray booth considerations.

I’ve recently purchased at UV light from UVIII and some finish from Simtec.

I talked with Mike at Simtec and they reminded me that I’ll need to purchase a sealed (explosion proof) fan and lights.

I don’t mind making these purchases, but I have a bit of a constraint when it comes to location.

My spray booth is about 7x9. Today I use a scratch and dent industrial range hood with a furnace filter taped to it. It vents to the outside through a dryer vent duct. That is the main problem. The designated spray area does not have one of the basement windows in it. So I’ll need to get creative on how to vent this higher power fan out. This hasn’t been a real issue up to now as I’ve just been spraying endurovar.

Can I build a fixture for the fan that has a simple 4” port on the back and vent it out the same dryer vent I’ve been using? Seems like the point is the high volume of air being pulled out, so piping into a 4” port won’t work (I don’t think ).

Second problem is getting fresh air into the room. Is it as simple as putting a couple air return vents on one of the walls and putting furnace filters on the outside to keep the dust out?

The basement does not have any vents from the furnace or AC to speak of, so the air would have to be pulled into the room from out in the main area of the basement.

Any pointers on this are appreciated.

Thanks!
Brad


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How many cubic feet per minute can this new fan move?

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Are you sure you're having a good idea?

I was looking at these from grainger:

https://m.grainger.com/mobile/product/D ... WP2IDP2PCP

They are 1700 cfm with an enclosed motor and aluminum blade.

I would take a recommendation if you have one on a specific fan.

Brad


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I know.

Maybe I have to just brush it on?


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I guess the short story is that I cannot cut a 20” hole in the side of the house. If I can reduce the exhaust side of the fan down to something reasonable like 4” or 6” I can vent that out the side of the house.

Or, it might be time to build a she shed.


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You need to move serious air in a spray booth.... an oven vent ain't gonna cut it!

Here is the basic formula for a cross flow booth;
Width of Booth (in feet) X Height of Booth (in feet) X 100, so assuming you are using the 5 foot and your ceiling is typical 8 foot that is 4000 CFM. now in reality your filter bank will be smaller, say 4 x 6 which works with standard filters so a minimum would be 2400 CFM. Try and flow that through even a 6 inch duct and it will roar like a jet if you can even get the static pressure to do it.

Short answer is you need good ventilation, even with these UV materials.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Yeah, I recently (and very briefly) thought about the UV cure route, but as long as it requires spraying with a dangerous material, I can’t justify the jump. I need to stick with fad/pad/brush applied finishes. I just don’t have a space that will work for the type of spray booth that would truly be safe.

This is good feedback. I was not planning to use the oven vent that I've been using with Endurovar, but you get my constraint. I have to pipe this outside somehow.

A second option is to take over a section of the garage for this. Still needing to open up something for the fan though. I'll need to think about this some more, but it could be an option.

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Although you still need great ventilation, you could use water based lacquer instead of nitro.... at least you won’t explode..



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I've been using Endurovar for the last 3 years. I like it fine, but am ready to play around with some other finishes.

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Pat has had good luck with the cureuv.com materials which are supposed to be VOC free. You could try that. Honestly, I might be trying that too if I don't get this spraybooth situation figured out.

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First, you cannot reduce 1700 cfm to 6" duct, let alone 4" duct. Second, most codes limit kitchen range hoods to 400 cfm without a separate air makeup system. Anything over 400 cfm exhaust in a domestic situation can induce negative air pressure in a house which leads to nasty effects like reverse flow from furnaces and water heaters. Flue gasses are pulled back into the living space. An all electric house would not have this same problem but 1700 cfm exhaust would cause a total air exchange in your house in very little time.

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You will need at least a 10" duct and filtered intake makeup air of the same or more. My booth was so powerful at 1500cfm that I could hardly get the door open with the fan running.

Just to be clear... I'm not planning to use the oven hood for anything. That was just used with Endurovar in a tiny closet and it worked fine for the last few years. I understand that it cannot be used with the solvent based UV products or Nitro.

The feedback so far has been super helpful. The air exchange aspect is something I wasn't fully getting, having no experience with fans of this size.

Thanks! Any other ideas are appreciated.

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Brad,

I also experimented with the Cure buddy and Simtec products. After using it on a couple guitars I ended up back where I started. Since that $3k experiment I've really improved my epoxy pore filling skills which is the main reason I wanted to try uvcure finishes in the first place.

So besides not blowing yourself up, you mentioned booth size. My booth is 4.5' X 9' and is plenty big enough for spraying a couple guitars at a time. I'm running an 18" fan mounted in a plenum with 4 4" ducts which daylight through the rim joist. The ducting is schedule 20 pvc and I'm using 20"x20"x2" merv13 filters for both intake and exhaust. I can spray 5-6 guitars before I need to replace the exhaust filter. This setup gets rid of any overspray immediately. Remember, I'm shooting waterbase finishes

There's been a number of times in my life where I probably should have asked myself this!

Thanks, Michael. Really helpful.

In the middle pic, on the left of the door, is that the intake to the room? It's pulling air from the main basement area. Correct? I'm trying to wrap my brain around this air exchange idea. Do you just pull air from the basement or do you make some other changes elsewhere as well to let air in? Like from the outside I mean. I talked with someone this morning and the issue of temp changes came up. It seems if you are just pulling air from the main basement area and only running the fan for a few minutes at a time it should be fine. Am I over simplifying it?

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Yes it is the room intake. The intake area is larger than the 4-4" ducts that exit the basement. Most of the time I'm pulling air directly from the basement. In nice weather I open an exterior door. My entire shop is humidity and temperature controlled. No matter how tight you build a space you will still have some air infiltration so some fresh is getting in from outside. On the last point, I think it depends on what you are spraying. If you are shooting waterbase having the fan on for a few minutes is sufficient. If you are shooting flammable stuff the fan needs to stay on!

This not pro-booth approach. It's just what I came up with to adapt the space to my needs.

Cheers, M

"Today I use a scratch and dent industrial range hood with a furnace filter taped to it. It vents to the outside through a dryer vent duct"

If it's the same vent the dryer is using it is probably a Bad Idea. Dryer vents have enough problems from lint fires and adding even water based finish material in the piping will help it catch even more lint.

"A second option is to take over a section of the garage for this. Still needing to open up something for the fan though. I'll need to think about this some more, but it could be an option."

A friend of mine uses his garage for spraying. He raises the garage door part way, installs a couple of box fans with furnace filters taped to them in the opening and blocks off the rest of it. For spraying a couple of small objects like guitars you don't need a powerful fan and tremendous air exchange. Although box fans are not rated as explosion proof, their motors are generally "non sparking" (shaded pole motor). Buy a good respirator and if the fumes linger slightly longer than they would in a pro booth it shouldn't be a big deal. If you are going to be spraying cars and cabinets then you will need something better.

Thanks, Clay. No, it is not the same as the dryer vent, it's on its one line.

Good points about the big garage door. The temps are gonna be hard here in Ohio. I guess limit spraying to spring and fall.

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That jump from hand application to spraying is looking less and less attractive to me . . .

Don't forget, you will also need an offgassing room, also vented.

Do not confuse VOC free with solvent free or non flammable.... And not all add copy is absolutely correct..... The MSDS for the product lists "Ketone Derivative" Which would definitely be a VOC! See the MSDS herehttps://cdn.shopify.com/s/files/1/1343/9763/files/UV-Cure-Premium-Clear-Wet-Look-Finish-Topcoat-MSDS.pdf

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks, Brian.

Don, where's your sense of adventure!!

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