Gluing plexiglass to polyethylene

Not likely because the solvent/glue for plexiglass comes in polyethylene squeeze bottles.

Never going to happen, but you can still get a seal between the materials.

Rough up both surfaces with a 36 grit right angle sander to provide a rough surface, then apply 3M 5300 caulk.

Allow 1 week to cure.

Lew

You're going to need an adhesive specifically designed for low surface energy plastics. These are not cheap. There are some made by Loctite and 3M among others. They are usually called structural adhesives and one example is 3M? Scotch-Weld? Structural Plastic Adhesive DP8010. You won't find this stuff in your friendly neighbourhood hardware store - it is only available from adhesives suppliers and a few specialty shops.

Do a web search on "polyethylene adhesive" and see what you find.

Mike

Gorilla Glue

I was going to suggest 3M 5200. It will glue anything.

I read somewhere that Hot Melt Glue may work. Can anybody confirm or deny that this will work?

Check out

My experience with hot melt glue in exterior applications has been less than satisfactory. I would certainly not use it if it, or the surface its holding, is at any time exposed to direct sunlight.

Sew the peices together with wire, so that they overlap in a way that sheds water. THere's no reason to try to make a hermetic seal, you're just trying to keep the window well from filling with water and debris, right?

Rough both surfaces and bond them with 30 minute epoxy. That's how I'd do it.

Ain't gonna work with glue. Even if you get it to stick at first, a week of sunlight and UV, and/or a week of winter temps, the first time somebody even brushes against it, it'll pop apart. Overlap the materials and use mechanical fasteners. For plexi and poly, I'd use pop rivets with big-ass washers on both sides to keep them from tearing out. If you need moisture seal, a couple beads of pretty much any caulking between the layers will work. To keep it pretty, I'd use a clear variety.

aem sends....

Epoxy isn't going to hold on poly.

Bob

Call a store that sells plastic only and ask them.

Seconded. In my experience nothing bonds properly with polyethylene.

Just a thought: it might be a plastic welding business could do it, but I am not sure if/how well polyethylene welds. Might be worth trying to find out though (I am thinking of welding a lip to the p.e. that mechanically holds the plexiglass, then sealing with clear silicone for instance.

I have got silicone to stick to p.e. but I wouldn't trust it to have any mechanical strength.

-Peter

Polyethylene can be welded, but I think trying to weld PE to acrylic would be like trying to weld stainless steel to aluminum.

Sme years back I had to buy a case of epoxy that was made specifically for hdpe, Seemed to work. It was an expensive and specific epoxy, not generic

Yes, with you there. That's why I suggested welding a lip to the polyethylene and sealing the plexiglass in (rather than trying to weld the twain together).

-P.

I can send you some 3M 300LSE 0.002" ?

Thanks. I did just that but used (4) 6-32 x 3/8" screws and sandwiched clear Silicone II Door & Window adhesive between the two sheets for water seal and supplemental bonding. Seemed easier and cheaper than ordering some of the more exotic adhesives needed to bond polyethylene.