Acrylic to Glass with Silicone??

fkshiu · #1 01-27-2007, 08:29 PM

Mixing materials is always a bit iffy. Silicone tends to stick to glass far better than to acrylic.

GE I silicone is "good", GE II is "better" while GE 1200 is the "best" if you can find it. 1200 is what aquarium manufacturers use.

I used 1200 to silicone acrylic baffles to a glass sump and it's watertight, but having to hold up against gravity and water pressure (being an outside pane as I understand your intentions) is another matter.

BCOrchidGuy · #2 01-27-2007, 08:31 PM

Thanks for the replies, yes I've got some concerns about the weight of the water, I made the overflow to be about 4 gallons so there is a real concern. I thought about sanding the silicone to give it more surface but I think I'll just head over to Rona and buy another diamond bit and keep cutting.

Thanks again.

Doug

Tangman · #3 01-28-2007, 12:03 AM

I think I'll just head over to Rona and buy another diamond bit and keep cutting.

Good idea, acrylic doesn't really bond to silicone any way...

BCOrchidGuy · #4 01-28-2007, 01:05 AM

Glass is cut, two 1 3/4ish inch holes. I cut the holes with my 1 1/4 hole saw then used the diamond bit on the rotary tool to enlarge it. Things went well until the clean up when I dropped my drill press on my toe. Usually it wouldn't be a big deal as I wear heavy shoes when working outside with power tools but we are having a birthday party and I didn't want to track all the crap through the house and the nice clean carpets so I took my shoes off at the door.

Anyway, the overflow is all glued up and will be glued to the aquarium tomorrow. When working with bulkheads it's nice to know the holes don't have to be perfectly round.

Doug

StirCrazy · #5 01-28-2007, 03:17 PM

don't use silicone as the bond won't be strong enuf to be safe. that is a lot of weight and silicone bond strength isn't as high on acrylic. there are some epoxys that would work good for this but the best bet would be to make your external overflow out of glass.

Steve

BCOrchidGuy · #6 01-28-2007, 06:46 PM

Thanks Steve, I've done the glass and got the bulkheads installed, one thing about your post I wanted to ask though is how do you bond epoxy to glass, I've tried it a few times and it's always peeled away with out any trouble. How do you clean or treat the glass so the epoxy sticks to it?

Doug

StirCrazy · #7 01-29-2007, 10:27 PM

Quote:

Originally Posted by BCOrchidGuy

how do you bond epoxy to glass, I've tried it a few times and it's always peeled away with out any trouble. How do you clean or treat the glass so the epoxy sticks to it?

Doug

you need the right type of epoxy, some are good on non-pourous and suck on pourous and some are the other way and some are inbetween.

Steve