I’m getting mixed search results on this. When using a acrylic/plexiglass panel in a plywood build, is there a sealant that will hold the panel in place without having to screw it down? Some are saying Dow 795 will hold on its own like plain silicone holds glass, but some are saying to must be drilled and screwed regardless.
Sealant for acrylic
- Thread starter BensBurms
- Start date
Ive done both screwed and unscrewed in liner tanks with windows…. Are u doing epoxy/fiberglass?
If you build ur window sill to hold the glass ull b fine unbolted. At the least put a 1” wide board/support across the bottom of the window to hold the weight on the glass. 1 up from there would b to do that with a full surround so the glass “sinks in” and becomes flush with the wood surround. U can then do u regular gasket seal and also another seal where the inside glass meets the surround.
As for sealents/silicone….
Dow corning 795 has always been on “the list” thats pretty dated tho and theres better/stronger options these days for acrylic gaskets.
Ive used Hutton products Gold label aquarium sealer/silicone with success.
Ive also used 3m 5200 with success and this is also on EPDM liner to acrylic which is worse of a bond than to epoxy.
Some of the newer ones that are proven over many times now are CT1 construction adhesive in black only and “my pond” MS300.
I also recommend sanding the acrylic with a decent grit where its going to be sealed at for better adhesion.
Lastly… yes, ur acrylic window will
fail if u just free float it on a flat piece of wood like you would for epoxy/glass. Bolts are a pain also…. Its much easier to do the window sill under the glass to support it or have the glass on the bottom of ur tank so thats taking the weight. 
