I have thin 0.015" aluminum plate I want to electrically isolate. It will be immersed in an emulsion, leaving the top unexposed for electrical connection. The plan is to sandwich the the aluminum between two sheet of 0.08 plexiglas. About 12" x 12". with 11" x 11" aluminum inside. I have found heating to 300*F for 20 minutes softens enough to form the edges.
I have tried a paint the manufacturer said would work, but 3 coats didn’t isolate it. I have experimented with sealing in plexiglass using Permatex Ultra Grey, that does work great on glass, not as good on plexiglas, just doesn’t adhere well. I have flame treated to melt the edges together, messy and hard to see where you sealed. I have heat formed it to get the edges to touch all around the sandwiched aluminum and then used MEK to solvent weld. The worked for 1-1/2 days and then leaked both physically and electrically. Are the actual plexiglas solvents better than MEK for the solvent weld? All ideas are appreciated.
Thanks, MavamQ
PS, For those in the know, I need over 200MΩ of resistance between two plates, in water, i.e. no leaks!
Acrylic solvent glue will absolutely seal the acrylic material. It requires good contact between the pieces being joined, but the result once joined is solid.
Since you are sandwiching the aluminum, I would probably heat form the acrylic first, then apply the solvent glue to the join, and let it wick into the join. This will “weld” the pieces together resulting in a sealed join.
I have seen claims that acetone can also be used, as the acrylic solvent can be pricey, but I have personally not had much success with it, as you noted.
What about running a bead of aquarium silicone sealant? It can handle a good amount of pressure when cured and is flexible to allow for thermal expansion.
It looks like Methylene Chloride is a great acrylic solvent, but rather hazardous.
I have heard of aquariums dumping fish on the floor days after being put together with silicone.
Just as I’m not happy with the adherence of Permatex Ultra grey to acrylic. Great on glass though!
I’m looking seriously at Weld-on 16, it is medium consistency so I think would fill crevices well.
Also a thought about dissolving acrylic chips in Methylene Chloride and using that as a solvent / crevice filler.
MavamQ
Why not just use glass instead of acrylic?
I have made 2 300 gallon salt water aquariums the have not leaked in the 10 years od service. Electrical conductivity is not a issue with the fish so much though weld on 16 is what i used