plexiglas glue

I wasn't sure where to post this question , but as a regular Neanderthal I thought I would start here .
What kind of glue does one use to "glue" plexiglas with ?
Thanks
Steve

Plexiglass glue?

Seriously, there's a proper glue for the stuff. Use the wrong stuff, and it'll craze and go stupid or it just won't work.

What are you planning to glue together? Might be that you can use something like epoxy if the glue line doesn't need to be clear.

Standard glues and epoxies don't work very well with plexiglas. You need more chemistry than that. I've used methylene chloride in the past. If your joint is prepared carefully, this stuff will dry perfectly clear and the joint will be very strong. My use of it has been limited to smaller applications but this may be what the big boys use as well. Not available at your local hardware store, you may want to call someone that works with plexiglas for a supplier - and further advice.

As Stuart said, it depends on what you are doing with it, how strong must he bond be? I've used silicone caulk to bond plexi before and it worked, but it didn't need be strong, just air tight...

There are 2 common methods of gluing acrylic sheet. The first and most commonly used is solvent cementing using methylene chloride in a syringe or squeeze bottle with a needle. WARNING: use in a well ventilated area only, methylene chloride is a suspect carcinogen. You scrape and sand the edges you are going to join to remove saw marks. Place the 2 pieces together and run the syringe along the joint. Capillary action will draw the solvent into the joint and weld the pieces together.

The second method uses a 2 part adhesive (PS-30) which is methacrylate monomer and a catalyst combination. In this case you leave a space of about 1/32" between the 2 parts to be bonded and use masking tape on the bottom of the joint. You then mix up the adhesive and fil the void with the adhesive mix. It is a process which takes a little practice to accomplish without making a mess.

Both adhesives are available from Craftics or from most plastics distribution outlets. The solvent is easier to use and hardens to the touch in seconds though full strength takes a few minutes for complete outgassing and evaporation. The PS-30 is stronger but far more expensive and the parts should not be moved until full cure at 24 hours.

At one time I used to be a plastics guy having taken Mr. Robinson's advice.

What Stuart said... any Loctite product will craze Plexiglas (or plexiglass).

I'm not at home, so can't look up the URL I have bookmarked there, but there are at least two good tutorial videos on the net about building Fish Tanks showing the process in detail about what to use and how to use it and the dos & don'ts. Google Plastics suppliers or Fish Tank building and you will probably find them. Do practice on some scrap pieces first to get the process down because the edges should be perfectly jointed flat & square with NO bobbles along the length for the capiliary action to work properly and create an invisible joint. IF you find that tutorial, it is VERY good.

+1 on Dave Anderson's post. I have used the solvent method which I believe dissolves the plastic and "welds" it together with success. Just don't breath it or get it on you -- it's not healthy stuff. And don't drip it on your plexi as it will mar it. Most plastics stores sell it, and the syringe type applicator you wil need. Also they have the drill bits that don't crack the plexi if you need holes.

IIRC we used either acetone or lacquer thinner to glue it together as flat sheets not corners. Attaching letters to signs. Whichever one makes it sticky.
Mike

I've used methylene chloride to assemble a fairly large plexiglas housing. It works like magic :) There have been times where I wished wood glue-ups would work as easily.

I use weld-on #4 if it has to look good and Weld_on#16 if it does not matter what it looks like. The smaller the number the thinner it it is. I made a couple of fish tanks using this stuff and it works awesome.

+1 on Dave Anderson's Method
20 years ago I worked in a Prototype model shop making lots of gadgets from plexi and we used Dave's medthod #1 and I guess for stronger joins ye used MMethos #2 but back them it was Pink dental power they used to set teeth in.. We spread the power in the corner and sqirted methylene chloride from a syringe in the pre-glued corner and it made a pink corner weld..

We also used bondo to fill seems before paint..