bonding acrylic to hdpe?

[DirtDiggler2823]

Since the silicone doesn't really bond that well to acrylic, what you want to do is create a dam around the edge. This will be more than enough for sump baffles.

Redbluefish said that silicone is made for use with plastics and will stick like hell to both. I'm trying to get a confirmation from them.

 

[redfishbluefish]

I'm doing acrylic baffles in a glass tank for a sump. This stuff will work?

Yes, this stuff bonds to acrylic (and glass) like you can't believe. The ones who claim silicone doesn't stick to acrylic have never tried this stuff.....it's great.

 

[DirtDiggler2823]

Yes, this stuff bonds to acrylic (and glass) like you can't believe. The ones who claim silicone doesn't stick to acrylic have never tried this stuff.....it's great.

I'll be using this where acrylic meets glass. Everywhere else gets a proper acrylic bond. Thanks! You're a life saver!

 

[paphater]

Redbluefish said that silicone is made for use with plastics and will stick like hell to both. I'm trying to get a confirmation from them.

I'm not saying it won't work. I had acrylic baffles in a glass sump using this stuff. I'm saying you aren't going to get a structural bond like silicone to glass. If you only silicone the edges like you would on a glass tank it is likely to fail. If you get the edges and create a dam so to say on the sides, it basically wedges it in there just fine. Here is a better technical explanation of it.
http://www.reefcentral.com/forums/showpost.php?p=21157556&postcount=16

 

[DirtDiggler2823]

I'm not saying it won't work. I had acrylic baffles in a glass sump using this stuff. I'm saying you aren't going to get a structural bond like silicone to glass. If you only silicone the edges like you would on a glass tank it is likely to fail. If you get the edges and create a dam so to say on the sides, it basically wedges it in there just fine. Here is a better technical explanation of it.
http://www.reefcentral.com/forums/showpost.php?p=21157556&postcount=16

I think I understand what you're saying. Sealing both sides with a bead of silicone was the plan.

 

[Hwrd69]

OK, even though it appears the OP has moved on to other options, this discussion on attaching acrylic to HDPE has sparked my interest. I've used the above referenced "plastic" silicone on acrylic to acrylic, acrylic to glass and polycarbonate to glass, and all worked great....can't peel the silicone off.

One of the tops to one of my Brutes (HDPE) has a hole in it that is no longer being used. I cut a circular disc of acrylic (I think 1/8 inch thick) and sanded both the acrylic and the area around the hole. I also sanded a little part of the center of the lid where I plan to simply put a dollop of silicone (to test pulling it off.)

Disc siliconed to the lid. Now wait for it to cure.

I'll be back in a couple days with results. :D :cool:

I'm a few years late in finding this post, but what were the results of your experiment? I'm in a bind right now with this situation and I can't find any good information on what works.

 

[redfishbluefish]

I'm a few years late in finding this post, but what were the results of your experiment? I'm in a bind right now with this situation and I can't find any good information on what works.

I totally forgot about that little experiment. I no longer have that Brute, but that silicone is my go to silicone and I've used it in a number of applications without fail. Here is an example of my 32 gallon Brute mixing can with an acrylic bar silicone'd to the inside of the Brute to hold the heater. About a year old and no issues.

Believe me, it works!