working with plexiglass

You are going to need to give more infor for #3. Like what are you using the stuff for?

Ed Lowenstein wrote in news: snipped-for-privacy@t10g2000yqg.googlegr oups.com:

Lots of good info here.:

Ken

Ask the manufacturer what "glue" to use. Most of it is like pvc plumbing, in which the solvent actually melts the two pieces together.

Correct, but potentially misleading -- the solvent you need is *not* the same stuff used for PVC plumbing. The principle is the same, but the substance is not. The stuff you need is called IPS Weld-On. You won't find it at Home Depot or Ace Hardware. Look in the Yellow Pages under "Plastics". Any plastics dealer either carries this, or can tell you who does. Check with sign shops, too.

Google "IPS Weld-On". You won't find it at home centers or hardware stores; look in the Yellow Pages under "Plastics".

Sorry, no idea. My best guess is that you'll probably need a mechanical fastener of some sort. Acrylic plastics are glued to each other with a solvent that essentially bonds them into a single piece. This process obviously won't work if the other piece is wood. Epoxy or cyanoacrylate ("super glue") might work -- experiment on scraps.

Depends on how large the boxes are. If they're only a handspan wide, 1/10" should be plenty. OTOH, if they're as large as you are tall, even 1/4" might not be thick enough.

-MIKE- wrote:

Wow, Doug. Really?

How is that misleading? I told him to ask the manufacturer. I wrote it's "like" pvc, not "is" pvc.

Are you a corporate lawyer or something? :-)

-MIKE- wrote:

I was not mislead whatsoever into thinking that Mike was suggesting the use of PVC solvent to bond plexiglass.

"Doug Miller" wrote

I have successfully glue acrylic 'Perspex' to wood with a general purpose hot melt adhesive. It pays to warm both surfaces before gluing.

I seem to remember that you can make an adhesive by dissolving scraps in glacial acetic acid.

Take care with the acid.

Jeff

All sorts of solvents. Exactly what depends on MSDS / OSHA regs in your part of the world. Talk to your plastic supplier, but really this is a simple problem and you just buy a jar of their recommended moonshine. There are two sorts - thin pure solvents and also thickened glues, made by dissolving plastic scrap in the thin stuff. One gives a cleaner job, the other helps to fill gaps.

Mechanical fasteners, with the ability to slide for cross-grain moisture movement of the timber. Otherwise use well-dried and long- seasoned stable timber, small linear dimensions and epoxy.

Depends on the size of what you're making, and what you can get. I make big display boxes from 6mm, small things from 3mm.

You need some tools, first of all a saw. Bandsaws work well, as they aid clearance of the swarf. A problem with working plastic like this is the "wooly" swarf that comes off, and its tendency to re-weld to the sides of the cut with heat. On my bandsaw I had to also remove the mesh finger-guard from the dust extract port, to avoid clogging. If you use a reciprocating jigsaw, it needs to have low vibration and works best with a mild pendulum action - swarf welding is the problem. Fretsaws work well too, but are obviously slow.

A belt sander (cheap benchtop mounted one, common these days) is a useful tool for finishing edges, before gluing. Straighter, smoother edges need less gap-filling from the glue and so look neater when finished.

Finish polishing is important. Use many different grades of wet & dry paper in turn (double the grit for each step) and you might find a powered sander helpful. As always, don't switch grits until you're finished with the larger grit, otherwise you end up with a polished mirror that has big scratches left in it. Final polishing used to be done with paste polishes (and took ages), but these days it's far easier to buy some Micro-mesh abrasives. These work excellently well for polishing acrylic.

These days, edge polishing of plexiglas is done with a flame.

I said "potentially misleading". And IMHO it is -- someone not reading carefully could conclude that PVC pipe solvent would work for that job. Since the OP clearly doesn't know what to use, I wanted to clarify for his benefit that it won't.

Be aware that there are different types of Plexiglass.

I bought acrylic doors for an entertainment centre that were cut to size on a tablesaw. By experimentation, I found that I could polish the edges by using a hand scraper to get rid of the blade marks and then a polishing wheel in a drill to finish them off. I was pleased to find out that it was a very fast process. Maybe not the established procedure, but it worked well for me.

Thanks, Upscale, that idea's a keeper.

You're welcome Doug. After first trying the process of increasingly finer grits of sandpaper and then using the polishing compound, I realized that impatience would get to me long before any edges were polished. So, I looked for a shortcut.

-MIKE-

Nope. he's just an agitator.

I did the same project many years ago and offer the following tips in answer to your questions.

Try reaching the acrylic manufacturers such as Rohm and Hass, DuPont and many others. They usually can supply booklets or web sites with details of fabrication which should authoritatively answer all your questions.

Automotive tail light assemblies used (and maybe still are) to made of cast acrylic plastics.

Joe G

It's been a few years since I had to do that, but the last time I did I smoothed the edges as best I could with a file before digging out the sandpaper. Took a lot less time than it would have to do everything with sandpaper, but I'll surely give the scraper a try the next time I have to do this. I expect it to be quite a bit faster than files.

-MIKE- wrote:

Yeah, ok buddy.