Questions about a spray area

[Rick Fisher]

I am totally new to spraying .. I have a basement which is dry and clean, and have been thinking I could use a corner for spraying .. This is a basement under the shop. Not a basement under a house.

The floor and walls are concrete. Ceiling is wood.. So I figured I would throw up some poly on the ceiling and walls. maybe frame up another wall to form a U ..

ceiling height is about 7'6" ..

I have a spray gun. only used it once. I dont picture myself spraying every day.. maybe a couple times a month.. tops..

What do I need to know ?

[Keith Downing]

I'll let some of the more experienced guys give you a full run down, but I will say that ventilation is going to be key. If you're going to be spraying anything potentially flammable, you'll probably have to invest in a full dedicated ventilation system including a fan or blower that is explosion proof (and they're not cheap). Even if you'll just be doing water based stuff, you'll still want to be really careful you don't end up breathing any atomized paint or finish.

[Wayne Lomman]

Rick, as Keith says, it will be all about the ventilation. The link below is a guide for spray painting freely available to Australian industry. It is worth a read. Actual details are in Australian/New Zealand Standard AS/NZS 4114. That is a document you have to buy and answers all the questions. Canada should have equivalent standards.

OK, that is the official way to do it. In reality you need a clean area (you have this), ventilation that will give you an air flow velocity of 0.5 metres per second, filter media to stop overspray escaping, an explosion proof fan ( look for second hand at auctions) and some sort of duct to direct the exhaust air away, preferably up in the air somewhere. It does not need to be flash to work. My temporary booth at my Adelaide job site is made from scrap ply framing and green house plastic with a portable fan. It works perfectly for all the high gloss joinery in the house. Cheers.


http://www.safeworkaustralia.gov.au/...20Coating2.pdf

[Jamie Buxton]

Ventilation and lots of lighting. You want to exhaust fumes and overspray from the work area, so you're not breathing it. And you want to be able to see what you're doing.

Your poly sheet plan... I'd put it on the floor and walls, but not bother on the ceiling. In my spraying (waterborne & HVLP), the overspray falls on the floor.

[Jeff Monson]

Yes, tough to do a good job spraying without good lighting. I spray in my garage. I put poly on the floor and use 2 large fans to move air, 1 behind me and one in front of the door to push the air out. Of course a good respirator! It has worked very well for me over the years.

[John TenEyck]

I spray - a lot - in my basement shop, including some very large cabinets. My shop is heated and I spray year round. I only spray shellac and water borne products, and I advise you to do the same unless you invest in explosion proof ventilation and lighting.

I use nothing more than 6 mil poly hung over nails in the floor joists to form a barrier curtain about 8 ft wide and 10 feet deep. I put brown Kraft paper on the floor; roll it up and throw it away when I'm done. The key to system is that I use my DC fan as my exhaust fan. I bypass the cyclone and bags and run a hose from the back of the spray booth to the fan inlet, and another hose from the fan outlet out a conveniently located window. That gives me about 1400 cfm of exhaust. What's the face velocity? I don't know. I calculated it once. It takes care of the overspray and that's all I care about. I have no residual overspray or fumes in my shop when I'm done and I sometimes spray for an hour.

I use no filters in front of the fan; you don't need them with a DC fan as it's used to handling dust. Filters just clog up. No filter - doesn't clog up. There is no build up inside my fan; it's about 8' downstream and the finishes are dry by the time they get that far so they don't stick. A little white powder blows out the window; it doesn't stick to anything.

To exhaust 1400 cfm you need to allow the same amount of make up air to come in. I open an upstairs window at the top of the basement stairs and let make up air in that way. Otherwise, it will pull air down my chimney, and that ain't good.

And, as mentioned, a good organics respirator and plenty of lighting. If you can't see the wet line you can't spray very well.

John

[Joe Jensen]

I spray - a lot - in my basement shop, including some very large cabinets. My shop is heated and I spray year round. I only spray shellac and water borne products, and I advise you to do the same unless you invest in explosion proof ventilation and lighting.

I use nothing more than 6 mil poly hung over nails in the floor joists to form a barrier curtain about 8 ft wide and 10 feet deep. I put brown Kraft paper on the floor; roll it up and throw it away when I'm done. The key to system is that I use my DC fan as my exhaust fan. I bypass the cyclone and bags and run a hose from the back of the spray booth to the fan inlet, and another hose from the fan outlet out a conveniently located window. That gives me about 1400 cfm of exhaust. What's the face velocity? I don't know. I calculated it once. It takes care of the overspray and that's all I care about. I have no residual overspray or fumes in my shop when I'm done and I sometimes spray for an hour.

I use no filters in front of the fan; you don't need them with a DC fan as it's used to handling dust. Filters just clog up. No filter - doesn't clog up. There is no build up inside my fan; it's about 8' downstream and the finishes are dry by the time they get that far so they don't stick. A little white powder blows out the window; it doesn't stick to anything.

To exhaust 1400 cfm you need to allow the same amount of make up air to come in. I open an upstairs window at the top of the basement stairs and let make up air in that way. Otherwise, it will pull air down my chimney, and that ain't good.

And, as mentioned, a good organics respirator and plenty of lighting. If you can't see the wet line you can't spray very well.

John

John, be very careful with Shellac, the solvent is alcohol which is explosive when atomized.
http://www.highlandwoodworking.com/w.../alannoel.html

[John TenEyck]

Thanks Joe. I carefully considered the hazards when deciding whether or not I could safely spray shellac in my shop. The flammability limits for ethanol are about 3 - 19 vol%. My exhaust fan moves 1400 CFM. My spray gun puts out about 8 CFM, and the quantity of alcohol in that is low. But to be conservative, let's take all 8 CFM as being saturated with alcohol. Divide 8 / 1400 x 100 = 0.57 vol% concentration. Even if you cut the exhaust flow in half it only goes up to 1.2 vol%, still nearly 3X less than the lower flammability limit.

Everyone needs to asses their own situation, or get someone knowledgeable to do it for them. I'm not advocating that what I do is safe for anyone else, only that I believe it is safe for my set of circumstances.

Be safe.

John

[Rick Fisher]

Thanks for the replies guys. I can install as much in lights that is needed .. I guess if I'm gonna learn to spray, I may as well learn to spray waterbased.. safety ..

i have an older squirrel cage fan .. can easily vent it outside.

Good feedback

[Wayne Lomman]

Note to all, while using water borne coatings reduces the explosion hazard, none of the other hazards associated with spraying are reduced. The aerosols are just as bad for you as any solvent borne coating. Solvent borne coatings have been around long enough that the health hazards are well understood. Water borne coatings do not yet have that body of data. Bottom line, water borne coatings may save the environment but they won't do any better at saving your life. Do yourselves a favour and research this. You don't have to take this grumpy old bloke's opinion. Cheers

[Jim Becker]

Wayne is correct...you still need to wear personal protection while praying water borne products. They still have solvents in them (water is just the carrier) and even if they didn't, particulates from overspray are not something you want to be breathing into your lungs.

The one negative for me to using your downstairs is...the stairs. Getting projects up and down might be a pain. Unless, of course, you have a lift.