Silicone

[gpajon]

Ok big question.

I've built lots of small to medium tanks but I have always had my large tanks made by someone else. Now I am taking the plunge and building a 480 for my own home. It would not fit in the door once it is done because of the way my house was built so i will have to put it together in the house.

My question is what silicone should I use. I know about GE and all the other 100% silicone sealants from Home Improvement stores but I want to make sure that there isn't something better. I would honestly prefer if it was labeled for aquarium use.

Gon

[Generic]

Same question, different reasons though!

I looked tonight, I saw the GE Brand Silicone I and II, the II specifically states not for use in FDA ## areas, or Aquariums. The Silicone I does not have this warning, does that mean its OK to use?

Murdock

[kgross]

GE Silicone 1, door and window is ok for aquariums, but there are better ones. I can't remember what one is best but it is in a post by acrylics.

Kim

[coolfish5]

My opinion is the GE stuff takes longer for it to cure. Maybe just a bad tube or something. I used Perfecto brand from my local pet store and it seems to work much better.
I think the GE 2 has some chemical in it to prevent mold/mildew growth, at least thats my guess as to why its not as safe.
John

[AnemicOak]

Most home improvement/hardware stores carry DAP Aquarium Silicone. Don't know if it's any better than anything else though.

[N8MAN1068]

everything i've read about the GE II says that it is fine to use, even though the tube says it is not...but those were freshwater guys w/ cichlid tanks, but i still trust them.

would there be a difference between fresh/saltwater?

[N8MAN1068]

http://communitytank.aaquaria.com/articles/resealing.htm

here's one of the guys who has
one of the other guys here has also bred some nice looking cichlids in tanks he's redone with GE II

I just can't seem to stomach paying $3 for a little tube, when i can get something large enough to put in a caulk gun for $2 more.

[Acrylics]

From what my GE rep tells me, the silicone I is for glass, II is for composites and other plastics. This jives with what I've heard around here as well, that II doesn't stick as well to glass. Silicone I is an acetoxy cure, II is a neutral cure which takes longer but sticks better to plastics, not well enough to be structural, but enough to seal - which is all it was designed to do.
There is no difference between I & II insofar as antibacterial or anti-mildew additives. Both have a "Kitchen & Bath" variety which contains these additives and a "Window & door" which does not contain any antibacterial / antimildew agents which *could* potentially harm your system.
The primary reason for II containing the "not for aquarium" disclaimer is for liability; since it was not design for using on glass - it will not hold as well on a glass aquarium.
Many have reported (but I can't confirm) that most aquarium silicones are repackaged silicone I - maybe so. The only silicone I'm aware of the specifically states "for aquariums" is DAP Aquarium Sealant, which is just another acetoxy cure silicone - you'll know it by the strong smell of acetic acid (vinegar) when opening. Dow Corning makes the implied disclaimer that it is a "sealant" rather than a stuctural "adhesive" to join two panes together.
If you were siliconing acrylic, I'd recommed Dow Corning #795 which is an industrial adhesive which happens to work very well on acrylic - still not well enough for structural applications though.

HTH, at least somewhat :)

James

[gpajon]

ok so the question remains, would you use GE I to construct a 500 gal tank? I've used it on smaller tanks but I have never built anthing that big myself.

[N8MAN1068]

and use GE I, not GE II....correct?
it's odd though, because the back of the GE II tube says that it's a 7 on glass.....the highest rating, while i think the I was lower...
my aquarium is glass, so i'd imagine the II would work better, and i've had a few other hobbyists tell me the same thing too..
hmmmm...i guess there's only 1 way to find out!

[N8MAN1068]

heres a thread from another forum which says ge II is ok, as long as you give it plenty of time to cure.
http://www.3reef.com/cgi-bin/yabb/YaBB.pl?board=Refugium;action=display;num=1083630120

[TroyPierce]

Originally posted by gpajon
ok so the question remains, would you use GE I to construct a 500 gal tank? I've used it on smaller tanks but I have never built anthing that big myself.
Just curious gpajon. If you're going to the expense and labor of building a large tank, speding several hundred on glass, why you would try to cut corners and save $3 a tube on silicone?

I've used a couple brands but for my last Sump project, I used AGA's silicone. Bought it from my lfs but you might be able to get a better deal online. This is the same stuff that AGA uses when THEY assemble their tanks.

AGA silicone comes in clear and black.

[gpajon]

Originally posted by TroyPierce
Just curious gpajon. If you're going to the expense and labor of building a large tank, speding several hundred on glass, why you would try to cut corners and save $3 a tube on silicone?

I've used a couple brands but for my last Sump project, I used AGA's silicone. Bought it from my lfs but you might be able to get a better deal online. This is the same stuff that AGA uses when THEY assemble their tanks.

AGA silicone comes in clear and black.

I am not cutting corners and expense has never even been spoken about till now. I want the best silicone not the cheapest. With that said if the GE is going to yield the same results as a much more expensive sealant then I would consider it.

I have used the AGA and the GE on several tanks. I used to set up large custom tanks for a living but it has been a while since that and the guy I used to get the tanks from passed away.

http://community.webshots.com/album/97251533fKOElP

[N8MAN1068]

nice tanks!

i have 3 tubes of GE II at home i plan to redo my 150 with. i've seen alot of people who've never tried it say dont do it, and the people who HAVE done it, say it works great, no problems, and the fish are thriving and healthy.

Sounds good to me.
$4 vrs. $8.....cheap wins. I'm not looking for a brand name, just something that works.

[gpajon]

Bump

[rahre1]

I just finished building overflows in my tank with Dap black 100% silicone...don't know how that compares to GE I or II. My thought on any 100% silicone, regardless of the method of cure, is to give 48-72 hours to cure completely. Any 100% silicone rubber should be nontoxic once it has fully cured. On the other hand, some are not 100% silicone and I believe are not recommended for tank use.

[rahre1]

Just read my Dap tube because you all scared the %^$%^!!! out of me after reading the thread (I had just finished siliconing a "faux" back of black acrylic with built in overflows. The Dap window/doors 100% silicone in black says safe for food use under the FDA. Thank GOD!

[N8MAN1068]

Originally posted by rahre1
The Dap window/doors 100% silicone in black says safe for food use under the FDA.


how does that tie into aquarium use? is it b/c of water or something?

I put one coat of GE II on my 150 the other day...about to go back out and apply the 2nd coat.

i wonder if there's any tests you can run to see if anything is leaking into the water? i mean, ....there has to be, i'd imagine

[gpajon]

Ok I think you guys are missing the point here. All 100% silicone works as long as there is no mildew preventers. My issue is strength. I am building a 400 or 500 gal tank and need to make sure the silicone is not going to take a crap on me with that much pressure. I have used GE on many small to medium sized tanks with no problems but should I use it on a tank this big with no worries.

[N8MAN1068]

i think the problem you'll run into, is that 99% of people wont want to take the chance on an aquarium of that size.
when i look at the GE II and i see a '7; (their highest rating) for glass....that sounds good to me. i'm willing to take the week it takes to reseal/ cure/2nd coat/cure/fill it up and test for a few days to make sure it doesn't leak. if it does leak, i'm only out 1 week and $4 for a tube of ge II, and i can come back and say it didn't work.

on a side note, it took me only 1 tube of Ge II to reseal my 150 tall.