How would you assemble it? How would you join the corners, top and bottom? I have 4 sheets of Lexan that are about 23 x 32 and are an odd thickness, don’t recall exactly, but right around 3/16. A friend gave them to me several years ago and I’ve just let them set and haven’t figured out how to assemble. I’ve had to drill holes in and cut sheets of Lexan or Plexiglass before and as some of you probably know it can be very easy to crack or split. I’ll probably use a piece of plywood for the back wall and the blower/fan will be mounted to it. I’d also like to have a full door on the front. All sides other than the rear wall would be Lexan.
What do you think? Maybe use some aluminum angle on the corners and glue in the Lexan? Possibly angle both inside and out on the corners? What type of glue or epoxy could I use? Hopefully something strong enough to hold both sides of a piano hinge for the door. Hinge across the top edge for an upward swinging door.
I know well the hazards of drilling lexan, the trick is to go slow and not push and let the drill do it’s job. Having someone to run water to cool the sheets helps. I have acrylic doors on my spray booth and they’re held on with nuts and bolts.
Believe it or not, but the easiest way of joining lexan would be a good silicone caulk. This is all that holds aquariums together! In fact, they make caulks just for aquariums. Here’s a link on how to build an aquarium, complete with pics on how to hold the pieces together while the caulk cures.
Any two part epoxy will glue the lexan to the aluminum angle iron, so you could mount a plywood back. I wouldn’t try to hold the plywood and lexan together with caulk as the plywood is too porous.
You didn’t say how thick the material is, but you may need to engineer some supports as larger surfaces of lexan can sag, especially the tops. If you have enough material, you could build up a frame out of the lexan itself in key areas and use MEK to glue them to the sheets.
If you choose to go ahead with this project, I would be VERY interested in WIP pics!
Reinforcing the corners with aluminum angle is a good idea. I’d put them on the outside. The big challenge is that booths really vibrate. If you have the room, separate the blower from your box with a short length of flexible duct, and mount the blower to the bench on a rubber pad.
One point missed about Lexan is it propensity to charge with static electricity. Static is a evil force while spraying. It can cause the paint to bend and weave after it leaves the airbrush and before it makes contact with the model. Many a good modeler has experience this at least once.
Consider the fact that it will attract paint residue, conduct static, can’t be cleaned with solvents to remove the paint over spray it attracts and in time will look foggy and dingy.
The other hazard that goes hand in hand with static and painting… static induced flash over. Give it some thought.
Hmm, the benefit of an earlier time zone has allowed Gerald to consider things that eluded my early morning thoughts. He raises some pertinent issues.
While I have acrylic doors, they are open when I’m painting and cause no issue with static interfering with the paint.
You might consider making the doors and roof out of the lexan, and stick to plywood or aluminum sheeting for the walls.
I used plywood for mine and I line the interior with white paper. The white helps with reflecting light, and is easily removed and replaced when they get covered in paint.
Yes, static is bad. Hadn’t considered that. And in this apartment in the winter time with a gas furnace it gets very dry even with humidifiers running. Would a ground strap running from the framework make enough difference to matter?
Overspray and cleaning isn’t a big concern, it would mostly accumulate on the floor and rear wall. If they got too dingy I’d paint them. The rear wall will be anyway.
I have it because it was free and was a convienent size. I’ve been told before it would be easy to glue in but wanted a second opinion.
What do you think Hawkeye? Would grounding make any difference? If not I’ll just build it out of plywood with a simple frame like the one I use now and use the Lexan for the roof and maybe the door.
Having some experience with signage, I agree that silicone is to be avoided for any sign where you want to change out the panels, but for a permanent spray booth it is a cheap and easy solution that requires no mechanical fasteners. Tapered drills are certainly the best to use for this material.
Tony,
I have plexiglass doors on my spray booth, and they were full of static when they were new, but have lost their charge over a relatively short time. I think a simple grounding strap would eliminate the initial issue with static, and it would cease to be a problem.
Lexan and Plexiglass are two completely different things and technically, they are both only brand names of products available under different names as well… but I digress.
There is no trick to drilling Lexan ( or any polycarbonate resin thermoplastic for that matter ) you can drill it, saw it, hammer it, bend it and it will not shatter or crack etc. Plexiglass on the other hand is complete junk and will break like nobody’s business. If the product you are using is cracking, it’s not real PRT.
I made a video a long time ago for another person on another site showing the two products side by side, as you can see, you can do anything to ‘Lexan’ without fear of it breaking. I apologize for the New England accent…
Ken, you’re absolutely right, I’m using the word Plexiglass when I mean Lexan. I have Lexan doors.
However, it’s not necessarily “junk”, at least the good stuff isn’t. Plexiglass is just one brand name for PMMA (Poly Methyl Methacrylate) Thermoplastic, others are Perspex and Lucite. Thin sheets can fracture easily, but thicker sheets are hugely strong. PMMA has been used for periscope lenses, windshields, and gun turrets during WWII, and almost all the large aquariums use PMMA, including commercial ones like Monterey Bay. Motorcycle visors are plexiglass, as are the windows used in police vehicles used to control riots. The clear protective walls in hockey arenas are plexiglass. The portholes in the Bathyscape Trieste used PMMA for the port holes, it can hold back the pressure almost 36,000’ below the surface of the ocean. PMMA can be joined with CA.
Lexan is the most common brand name for Polycarbonate Thermoplastic, and is used in the manufacture of plastic bottles, CD/DVD discs, sun glass lenses, headlight covers and R/C bodies and parts. Bisphenol A, the material so many people are worried about in contact with food, is a polycarbonate. Polycarbonates cannot be glued with CA, as it disassembles the molecular structure.
There are some “knock-off” materials that are often confused with Plexiglass, which are the junk you show in your video. It tends to be optically imperfect and often looks hazy. Plexiglass and Lexan are optically pure. In fact PMMA is used in the manufacture of hard contact lenses.
Bill, thanks for all that but I wasn’t just referring to you, just the comparison of the two products in general.
Also, there was no confusion, that junk I have in my video is no ‘knock-off’. It is commercial grade, 1/8" Plexiglass from my fathers shop. He has been involved in the glass business for over fifty years, I have been involved, in one way or another for over twenty five.
I stand behind my video and everything I said about that ‘junk’ Plexiglass. I said it was only my opinion…
as an experienced glazier that is.
NHL-approved CrystalPlex is not standard Plexiglass, and plexi/lexan/lexonite etc. bonds better with Tenax/Proweld/Plastruct or any other MEK type glue than it does with CA but I’m not here to argue, take from my post what you will.
LOL! You don’t have to look embarrassed about it! [;)]
All I know is PMMA is used for all the things I referenced in my post, and I have a sheet of it replacing a window in my house that was broken by a rock flung by a lawn mower. I replaced it with plexi bought from the local glass co. and it’s been hit a couple of times with balls and rocks and it bounces right back!
I used to work for a printing company that had a division that was a sign company, and they used a “commercial grade” product called Variolux, that had the same hazy appearance I noticed in your video. It was garbage! We were lucky to get the sheet delivered from the supplier without damage!
You try telling people you’re a Glazier when they ask what you do and see what kind of reactions you get and then come back here and tell me that. [:P]
If the piece in my video looks hazy, it’s because it’s just a scratched up cut off from the floor of my fathers shop. He wouldn’t be too keen on me making silly videos for modeling buddies with perfectly good product. As far as rocks bouncing off, I believe it. ‘Plexi’ can be particularly strong when hit on it’s surface, especially if there are no holes drilled in it and of course the thicker, the stronger.
However, drill some holes into it and mount it under tension like a curved boat windshield, expose it to the hot sun all season on the water and then freezing temperatures in storage all winter. Then bring it back to us in the spring to install some Lexan like we told you to in the first place because of all those hair line cracks that have formed around the holes. (true story)
LOL! That does sound funny. “I’m a glazier by day and I model at night”! [:D]
I started in the print industry as a stripper. Film stripper, that is. We used to use photographic film that had an emulsion layer. You would expose the image you wanted, then “strip” off the excess film. That got me some strange looks!
OK, now that we’ve established some of the differences, what’s your opinion on static camokid? What I have is Lexan and it still has the protective covering so I can get whatever information is on it. I haven’t drilled these particular sheets or tried to cut it and probably what I’ve tried drilling or cutting before was cheap plexi. And however I decide to incorporate it in my booth I want it to stay put so if it will take it I’ll happily drill it.
I appreciate the input but I’m not spraying down my booth every time I go to use it.The new booth will have a door or doors, will be a rectangular box and I’m not going to make it collapsible. As long as the filter covers the opening for the blower it will be fine. I may have to use a larger or second blower in the future but for right now what I have will have to do. With a plywood rear wall that will be easy to handle. Whether it ends up being Lexan or plywood it will have interior lighting and plenty of it.
unfortunately I don’t really have any input on the static question in this situation, it very well could cause a problem as was brought up. For an example of just how much of a problem static can be, simply begin removing the protective ‘paper’ and watch as almost every small particle within a foot or so gets sucked and stuck to the surface and jump over your hand and back to the surface as you attempt to wipe it off. In our situation however, once the product is installed and we’ve washed it down, we no longer have any issue with static. Having said that, we have never installed it in a spray booth like you want to do, so I really have no idea (other than speculation) what may happen. A ground strap may be the answer or it may do nothing, experimentation may be the answer to see if there is a static problem (without any flammable liquids around of course)
I used a piece of 1/4 inch Lami (laminated safety glass) in the top of my booth to mount the light as I can clean the over spray with Windex and a new razor blade without the fear of scratching, the rest is plywood but Lami isn’t cheap and I get my glass for free. I usually try to steer people away from using plastics if they can, in your case it was free so I completely understand your desire to use it. I have installed some of the most expensive types of bullet resistant polycarbonate in banks over the years and even then, on occasion we are called back because of the eventual scratching/fogging that has happened. Unfortunately no matter how much you pay for a product or what that product claims to be able to withstand, the night cleaning crew removing scotch tape/stickers with a razor blade and scotch brite pad isn’t covered under warranty. [:P]
Even if yours were to scratch or fog up or yellow over time, it would still allow the light to penetrate so I don’t really think that is an issue for you, I’m not sure if I would construct the whole thing out of it though, maybe just the top to allow light and the doors at most? I would make the back and sides from plywood but that’s just my opinion.
Since you’ve said it is Lexan (polycarbonate) and not Plexiglass (acrylic) you can drill holes to mount hinges or angle reinforcement or whatever, without fear of breaking. There is no need to go extremely slow, drill backwards, buy special tools etc. as it is virtually indestructible. You wont be able to cut the sizes like you would with acrylic, IE: score and snap, you will need to use a saw with a fine tooth blade and go slow. Not because of fear of breaking but because it will heat up and melt and gum up the blade. I prefer a table saw with a finish blade myself but it can be done with a saber saw/jigsaw etc. If you watched my video, you saw me bend it back and forth and rest at a 90% angle, impossible with acrylic, if you try to score and snap, it will merely bend at the score without breaking. (unless you spend the entire afternoon scoring through the entire thickness)
Just drill the holes larger than your fastener to allow for expansion and contraction and if possible, use a finish washer or something similar to allow the plastic to move around on the fastener. If you’ve ever seen a buckled/bowed, wavy piece of ‘plastic’ installed somewhere, it’s because they didn’t do that.
A simple test for anyone wondering if they have poly or acryl, lay it on the cement garage floor and hit it as hard as you can with a hammer, did it crack/shatter or simply dimple the surface? Poly is king, Acryl is it’s lowly stable boy who mucks the stalls. [;)]
Now that Ken’s straightened me out on what type of doors I actually have, I can attest that static is a huge issue when you peel off the protective coating, but that once the static is discharged, it does not recur without some serious rubbing. And if you’re doing that to your spray booth, you have bigger problems than static! [:P]
