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View Full Version : What silicone to use to bond Acrylic to Glass


riseandfloat
07/05/2011, 12:55 PM
I am setting up a 20G sump and will have four baffles made out of acrylic in an all-glass tank that I will need to seal in. What kind of silicone should I use? Can I use the All-Glass aquarium safe silicone that you can find in most pet stores?

billdogg
07/05/2011, 02:37 PM
for your useage, I would just get a tube of GE I windows and doors (No mold inhibitors)

you really are not bonding the acrylic to the glass - more just sort of making a silicone wedge to hold them in place.

sfsuphysics
07/05/2011, 03:43 PM
I used Dow Corning 795, as it's actually an adhesive, also bonds very well to acrylic/plastics. However it's a bit more expensive than the GE stuff, and you need to order that online as your big box stores won't carry it.

Ronic
07/05/2011, 04:20 PM
One type that i have never seen anyone post is
http://www.americansealantsinc.com/asi-502-industrial-silicone-sealant-adhesive/
It is what i use at work and the stuff is great. And it will bond acrylic to glass no problem.

suffolk.reef
07/05/2011, 04:33 PM
I have allways had great results with Amazing Goop.

riseandfloat
07/05/2011, 11:03 PM
That's funny you say that sfsu I actually work for Dow Corning... so now you're probably wondering why I am on here after stating that I work for a company that specializes in silicone applications... but I am looking for something that is aquarium safe. Don't you guys worry about using certain silicones that aren't directed towards aquarium use?

And billdogg, that tube of GE you recommended, I was reading earlier and a guy was questioning whether this particular silicone was affecting his corals? Is it possible that this silicone could slowly leach out ammonia?

captnslapy
07/06/2011, 12:31 AM
One type that i have never seen anyone post is
http://www.americansealantsinc.com/asi-502-industrial-silicone-sealant-adhesive/
It is what i use at work and the stuff is great. And it will bond acrylic to glass no problem.

they also have an aquarium sealant. why not use that? Where can I get this? Does it have to be ordered?

Chris27
07/06/2011, 06:47 AM
I have allways had great results with Amazing Goop.

+1 - Great stuff. When cured, it's a much better bond between acrylic and glass then silicone. It's sold at Home Depot and Lowes for around $4 a tube.

coralnut99
07/06/2011, 07:59 AM
+1 - Great stuff. When cured, it's a much better bond between acrylic and glass then silicone. It's sold at Home Depot and Lowes for around $4 a tube.

+2 The only downside in my mind is that the stuff sets up pretty hard. So if you have to remove it for some reason, the process is just different.

madean
07/06/2011, 08:12 AM
I like the rtv 100 series. I have never had any problems with it. If you find the spec sheets fordow corning products or the rtv products you will see the tensile strength after the curing process blows away the cheap junk sold in most lfs. But then again your making a sump, and a small one at that. There are a lot of threads here on rc for this topic. Do a search, I remember people actually posting spec sheets for many types of silicone and adhesives so that you can make your own decisions. My only advice is to be patient and let it cure longer than what the back of the tube says.

Acrylics
07/06/2011, 08:36 AM
That's funny you say that sfsu I actually work for Dow Corning... so now you're probably wondering why I am on here after stating that I work for a company that specializes in silicone applications... but I am looking for something that is aquarium safe. Don't you guys worry about using certain silicones that aren't directed towards aquarium use?

And billdogg, that tube of GE you recommended, I was reading earlier and a guy was questioning whether this particular silicone was affecting his corals? Is it possible that this silicone could slowly leach out ammonia?DC 795 is used in every public aquarium in the world, sticks better to acrylic than any other silicone, period :)
As a neutral cure, it needs to cure longer so it can complete the outgassing process - about 2 weeks. I'd venture to guess that most problems people have with neutral cure silicones is not allowing it fully cure. If used too quickly, can release ammonia. Tubes say 48 hours to cure, but this is for household applications, not fish related.

The one that Billdogg mentioned is an acetoxy cure and cures relatively quickly. But even at that, only releases acetic acid.

Anther good one is the GE 1200 series, very safe and cures quickly (acetoxy cure)

James