Cheap Mans' Spray Booth

or you could get an old monitor, throw out the guts, hook a dryer hose up to a hivol squirrel cage fan and vent it outside with a filter before the fan. cut a hole in the back and sillycone the hose and you have a $20 paint cabinet.

I did that, and wrote an article for Ships in Scale, and it appeared in the Jan/Feb 2004 issue. Some hobby shops sell quite old back issues, so it may still be in some shops, but you may have to write the publisher (they do sell back issues).

I used a muffin fan, furnace filter, and the deluxe feature for the first time in any of my homemade spray booths, a light in the top.

I don't recommend that approach. Try to find a discarded stove hood (if that's the correct English name), set it on its end so the filter area is vertical, attach a dryer hose which goes out of the window, and voila. A stove hood has the required capacity (cfm) for a modeler's spraybooth, a computer fan definitely hasn't. The hood's fan motor possibly sparks, so there is a theoretical explosion risk, but I never ever heard of that occuring, and in my 15 year use of mine I never suffered an explosion either.

Rob

My models:

Me 163B site: AQM-34 site:

Yup, it does. Mine looks like that:

It uses a bathroom fan (with a furnace filter in front of it), and a low-voltage fluorescent tube for lighting. All in all maybe $30 in materials.

There is a risk of sparks from the fan motor igniting the fumes, but the amount of vapor is such a small fraction of the total airflow that I don't consider this a great risk. As an experiment, I just tried to ignite paint thinner fumes with my piezoelectric lighter (don't try this at home, kids). I got a small glass jar with some thinner, screwed the top off (fumes were strong enough to peel my nose lining), and stuck the lighter into the jar, with the spark plug about 1 cm above the surface of the liquid. This should be a worst-case scenario (very high concentration of vapor). In about 10 seconds of making sparks, the vapor did *not* ignite.

Not really. Your mixture may not have ignited because it was too rich. I'll bet that if you got the right mix of air into it it may have torched off.

My idea is to make a downdraft set up with a cardboard wardrobe box, a furnace filter, and suitable lighting. But I have yet to find a fan motor that I'll trust...

I'll do some more checking.

I did look into safe fans, but the only ones I could find were insanely expensive ($100+, five times more than the fan I use now)

According to our maintenance dept who are currently working on a full size industrial spray booth for Painting applications. You should look for a squirrel cage fan with the motor outside the air path. The CFM rating should be 100 CFM for every square foot of the opening size. I built my Spray booth from a shipping crate 22X25X27 I put a furnace filter across the opening duct in the back and built a support for the fan in the back which then vents outside via a aluminum duct.This is a semi perminent installation as it weighs in about 100lbs.Also covered the inside with aluminum flashing riveted to the wood to make cleanup easier.I talked to them about a bathroom fan and they quickly told me that it only takes one spark under the right conditions and paint thinner/lacquer thinner will explode with the force of half a stick of dynamite. For my money I would be very cautious when it comes to building a paint booth. If it were to explode you homeowners insurance may not cover the damage because of flammables being used. Hope this helps

snipped-for-privacy@xxxxmsnet.nl.invalid (Harro de Jong) wrote in news:1h0on4f.10dfau7ekqwuvN% snipped-for-privacy@xxxxmsnet.nl.invalid:

Way to practice good scientific method.

Now this idea makes sense...

Muffin fans (which I used in my homemade booth) are spark free. They are the most economical type too, in terms of CFM per buck. You need at LEAST 100 cfm.

Harro de J>

I got my 125 cfm muffin fan for 19 bucks.

Do a better job, then.

But what paint was it intended to thin?

Acrylic thinners are alcohol+water - low flammability

Enamel thinners are white spirit - low flammability

Lacquer thinners are acetone, MEK or toluene - high flammability

That said, I doubt there is much chance of an explosion in a modellers spray booth, as the quantities of vapour present are simply too small. We are spraying small areas, and mostly in short bursts.

Enamel:

My thought as well. I'll try and find some more information though (exactly what concentration constitutes a flammable or explosive mix)...

One caveat to my assertion above: the modern Revell paints describe themselves as Enamel Paint on the tin, but *don't* thin with white spirit. Further research on my part finds that they are "synthetic enamels" - whatever that is. But although you can still clean your brushes with white spirit (mineral spirits in US English, I think)

*don't* try to thin the paint with it - you'll end up with something that takes three weeks to dry/set/harden. You can guess how I found this out - - -

Use Revell Thinners with Revell paint (but don't waste it on brush cleaning). No, I don't what Revell paint thinners consist of, either, Revell don't tell you on the bottle or on their website

. What I did on my latest booth was to fit a flange over the muffin fan outlet, the flange used on house walls to fit dryer vent. I bought another, and mounted it to a strip of particle board about 8 inches high (after cutting hole, of course). I then stuck that board under a window sash and ran a piece of dryer hose from booth to window board.

For what it's worth;

I have a work safety leaflet for Revell products printed and distributed by the local (Finnish) agent of Revell in stores selling their products a couple of years ago. Date of the leaflet is 1999 and language is Finnish and Swedish.

The document states that the "Revell Color mix Thinner" consists of

90-99% of "liuotinbensiini" and 1-10% of butanol (=butyl alcohol).

"Liuotinbensiini", according to the Finnish Insitute of Occupational Health (

) data sheet is a common name for a variety of carbohydrate solvents consisting of C9-C12 carbohydrates. English language examples being " mineral spirit, white spirit, stoddard solvent" and " VM & P naphtha".

The Revell enamel paints are reported to contain 12-70% of "liuotinbensiini",

Isn't the vehicle in Testors enamels toluene, or something like that?

Not to mention that they are clearly labeled "CAUTION: Flammable. Read cautions on back.".