Chemically Resistant Plastic Sheet for top of spray booth

[Alan Lightstone]

Well, getting close to completing the spray booth in my finishing room. The explosion-proof fan and louvers are installed, filtered makeup air established, but now I have a problem.

I need an approximately 72"L x 40"W plastic sheet to go over the top of the booth, between the overhead lighting (way up there) and the spraying table.

I commonly spray lacquer, so I need something that tolerates that.

Looking at chemical compatibility tables, it appears that acrylic and polycarbonate are out. Is that true for spraying as opposed to soaking in the stuff for days?

I had thin clear plastic sheeting rolls I used on my last spray booth, which did great, but I'm looking for a more permanent solution.


Are acrylic or polycarbonate sheets ok for this???

Would putting a stripable coating on it be necessary? Clear Strippable Coating/ (http://strippablecoating.com/product/boothcoat-5140/) I've never done that before.

[ChrisA Edwards]

I assume you want as much of this over head light as possible to come down onto your spray area through this material.

As it sounds like this will be a fairly permanent structure around your spray table, how about building a frame that would hold drop in glass panels. They'll let the light through and can be scraped pretty easily, periodically, to remove the over spray.

[Erik Loza]

HDPE sheet.

Erik

[Frank Pratt]

I assume you want as much of this over head light as possible to come down onto your spray area through this material.

As it sounds like this will be a fairly permanent structure around your spray table, how about building a frame that would hold drop in glass panels. They'll let the light through and can be scrapped pretty easily, periodically, to remove the over spray.

Not sure I'd want to be throwing away a big piece of glass every time it needed cleaning.

My inclination would be to build a light weight frame and staple 6 mil poly to it. It's easy and cheap to replace when needed. Strippable coatings are great, but by the time you set up, spray it on, then clean the gun, you could have the poly replaced & have time left over.

[Erik Loza]

Just re-read saw that it needed to be a clear, ceiling-type thing. Please disregard the HDPE comment (for table tops). Polycarbonate should work fine. Just plan to replace it every so often.

Erik

[Alan Lightstone]

Polycarbonate would work OK?

When I looked at the compatibility list on some chart I found online, it said it hates lacquer. But they test these things by immersing them for 48 hours, so they may be testing in extreme circumstances.

They were talking about crazing.

[Alan Lightstone]

As an aside, I will need to be able to slide this panel forward to replace the filters.

[Erik Loza]

As an aside, I will need to be able to slide this panel forward to replace the filters.

Whetever material is going to get messed up, anyhow, so I would just consider it a periodic consumable. Personally, I would go for a multi-walled polycarbonate sheet like 4mm or 6mm Polygal. Polygal comes in clear as well as a bunch of tints and is actually often used as troffer lighting diffusers. Solid polycarb (or acrylic) sheet will sag unacceptably unless there are lots of cross braces.

Erik

[ChrisA Edwards]

Not sure I'd want to be throwing away a big piece of glass every time it needed cleaning.

My inclination would be to build a light weight frame and staple 6 mil poly to it. It's easy and cheap to replace when needed. Strippable coatings are great, but by the time you set up, spray it on, then clean the gun, you could have the poly replaced & have time left over.

The idea of using glass is that it's not disposable, it's cleanable.

Glass panels, made in a grid like a Colonial style window, say 12" x 12", just laying in a frame. You remove a panel, when it gets covered to the point of needing cleaning, scape all the overspray off in about 30 seconds with a razor blade and you are good to go.

[Frank Pratt]

The idea of using glass is that it's not disposable, it's cleanable.

Glass panels, made in a grid like a Colonial style window, say 12" x 12", just laying in a frame. You remove a panel, when it gets covered to the point of needing cleaning, scape all the overspray off in about 30 seconds with a razor blade and you are good to go.

Gotcha. I saw 'scrapped' & just assumed throw away. The only issue with using glass is that with a large panel of it overhead, breakage would be a safety issue, unless it's tempered.

[Alan Lightstone]

Gotcha. I saw 'scrapped' & just assumed throw away. The only issue with using glass is that with a large panel of it overhead, breakage would be a safety issue, unless it's tempered.

Yeah. That and weight worries me. It will need to slide horizontally to enable filter changes. Not terribly fond on sliding glass over my head that could potentially fall on me.

[Alan Lightstone]

Thanks for the advice. I went with a Twinwall Polycarbonate sheets. As shipping was ridiculous for full-sized sheets (6' x 4'), and I couldn't find any locally, I opted for two 2' wide sheets and I may tape them together. Dropped shipping costs from $300 to free. Hard to argue with that.

[Marc Jeske]

Like Frank said in post #4 - Why not just plain everyday 4 or 6 mil Polyethylene sheet stapled to a simple wood frame ???

Same stuff often used under concrete or as vapor barrier... Like total $5 in matl.

Why waste $ ?


One time I had some 3/8" Plain Lexan that I for whatever reason cleaned w common Brake cleaner spray from NAPA.

NO apparent damage... NONE... till few days dropped it on floor and it shattered like tempered glass.

Be aware.

Marc

[Alan Lightstone]

Long story short, it needs to be moved every time I change the filters, and I thought a rigid panel would be easier.

I used the 6mil Polyethylene sheet velcrod to a frame on my last spray booth. Never liked it. Cheap, but annoying.

My $0.02, or in this case about $200.