Polymershapes 100% Silicone

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Charney

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Do any of you have experience with Polymershapes 100% Silicone ? I am not using the bond glass, but plastic underwater. On the label it says do not use for submerged marine use. Anyone know why? I’m using it in Freshwater.
 
I'm pretty sure that GE Silicone I has the same warning on it. I can point at several examples where that has been holding, still strong and waterproof, for at least 30 years, but maybe that's just not long enough to be sure? :)

I'm almost starting to suspect that it's a CYA liability thing; if you don't use it correctly, it may fail, so best to just sidestep the possibility of being sued by putting this disclaimer on it.

I'm not saying your particular stuff is safe, just that warnings are sometimes lawyer-inspired overkill.
 
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I'm pretty sure that GE Silicone I has the same warning on it. I can point at several examples where that has been holding, still strong and waterproof, for at least 30 years, but maybe that's just not long enough to be sure? :)

I'm almost starting to suspect that it's a CYA liability thing; if you don't use it correctly, it may fail, so best to just sidestep the possibility of being sued by putting this disclaimer on it.

I'm not saying your particular stuff is safe, just that warnings are sometimes lawyer-inspired overkill.
That’s similar to what I was thinking
 
Id look into silicones with better proven adhesion to plastic like 3m 5200, CT1 construction adhesive and Gold Label aquarium and pond sealer silicone. Theres a couple others popular with the EU koi crowd for liners/skimmers etc. sanding the plastic helps but IME 100% silicone just rips right off of any type of plastic. I believe these other “silicones” i mention are part polyeurathene rather than 100% silicone. The CT1 is very good stuff, only the black is fish safe.
 
Id look into silicones with better proven adhesion to plastic like 3m 5200, CT1 construction adhesive and Gold Label aquarium and pond sealer silicone. Theres a couple others popular with the EU koi crowd for liners/skimmers etc. sanding the plastic helps but IME 100% silicone just rips right off of any type of plastic. I believe these other “silicones” i mention are part polyeurathene rather than 100% silicone. The CT1 is very good stuff, only the black is fish safe.
I am using it for fiberglass. Are the ones you recommend still better? Do they form a permanent seal or can they be removed? I do want to be able to remove it. Thank you
 
Id look into silicones with better proven adhesion to plastic like 3m 5200, CT1 construction adhesive and Gold Label aquarium and pond sealer silicone. Theres a couple others popular with the EU koi crowd for liners/skimmers etc. sanding the plastic helps but IME 100% silicone just rips right off of any type of plastic. I believe these other “silicones” i mention are part polyeurathene rather than 100% silicone. The CT1 is very good stuff, only the black is fish safe.
I completely missed the part about plastic. Yeah, Silicone I is pretty useless on most plastics I've tried; you can usually just roll it right off with your thumb.

I was about to suggest a product I discovered a year or two back, I think possibly at Russ's recommendation (?), called Geocel 4500 roof bonding sealant. I contacted the maker and confirmed that it would work with glass, and used it with excellent results to bond glass to an EPDM pond liner. Since then, I've used it for glass, epoxy, several types of plastics including ABS, concrete, dry clean wood, metal...this stuff just works with every combination of these things and I'm sure lots more. I think it would adhere an oily rag to an ice cube. More expensive than silicone but not insanely so, and I eventually even found it in stock in a couple of hardware stores.

But...now you say you want to be able to remove it too? :nilly:

Lol, anything else? A fresh clean aroma? Choice of colours? Maybe tastes good as a condiment on burgers or hot dogs? :)
 
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I am using it for fiberglass. Are the ones you recommend still better? Do they form a permanent seal or can they be removed? I do want to be able to remove it. Thank you
any type of silicone is not permanent to plastics like it is to glass… you would be able to remove it from fiberglass/epoxy if needed also. Do you know if ur fiberglass tanks are epoxy coated or gel coated? Viktor used hutton products gold label aquarium and pond sealer on gel coated fiberglass with good results. Im not sure if he sanded it before hand tho. Gold label is an excellent product but hard to find in the u.s…. I paid around $27 a tube for it for a tank build back in 09’ and had a local pond shop special order it for me.

I believe the geocel 4500 and the CT1 are a bit newer comparable types to the gold label. Both of those are extremely popular in the UK for koi ponds for bonding “mixed materials”…
 
any type of silicone is not permanent to plastics like it is to glass… you would be able to remove it from fiberglass/epoxy if needed also. Do you know if ur fiberglass tanks are epoxy coated or gel coated? Viktor used hutton products gold label aquarium and pond sealer on gel coated fiberglass with good results. Im not sure if he sanded it before hand tho. Gold label is an excellent product but hard to find in the u.s…. I paid around $27 a tube for it for a tank build back in 09’ and had a local pond shop special order it for me.

I believe the geocel 4500 and the CT1 are a bit newer comparable types to the gold label. Both of those are extremely popular in the UK for koi ponds for bonding “mixed materials”…
They are gel coated
The silicone i originally mentioned is labeled for plastics if that makes a difference
 
I completely missed the part about plastic. Yeah, Silicone I is pretty useless on most plastics I've tried; you can usually just roll it right off with your thumb.

I was about to suggest a product I discovered a year or two back, I think possibly at Russ's recommendation (?), called Geocel 4500 roof bonding sealant. I contacted the maker and confirmed that it would work with glass, and used it with excellent results to bond glass to an EPDM pond liner. Since then, I've used it for glass, epoxy, several types of plastics including ABS, concrete, dry clean wood, metal...this stuff just works with every combination of these things and I'm sure lots more. I think it would adhere an oily rag to an ice cube. More expensive than silicone but not insanely so, and I eventually even found it in stock in a couple of hardware stores.

But...now you say you want to be able to remove it too? :nilly:

Lol, anything else? A fresh clean aroma? Choice of colours? Maybe tastes good as a condiment on burgers or hot dogs? :)
These are two large custom-made, fiberglass aquariums made with panels and gaskets. They were built to be able to put together and take apart. The silicone is just for a little extra piece of mind.
 
These are two large custom-made, fiberglass aquariums made with panels and gaskets. They were built to be able to put together and take apart. The silicone is just for a little extra piece of mind.
In that case, do you really want it to adhere to the surface at all? I've used silicone in the past strictly as a gasket as well, with a couple of different materials. I've even sprayed the surface with light oil or silicone spray first to prevent adhesion. Lay an even bead of silicone over the contact area, bolt the thing together very lightly, let the silicone completely cure, and then tighten the bolts to squeeze the cured silicone "gasket" that has been formed.

It's an easy thing to do with a small surface area or small project; depending upon the size and design of your tanks, it might be more difficult or even impossible.

Are these tanks designed and intended to be taken down and re-assembled multiple times? Or are they built like this simply to make transportation and shipping easier once, with the intention being that they will be assembled once in place and then left together permanently?

If the former, a silicone gasket made as above would seem to be workable, although it would require stripping off the old and replacing with new each time the tank is disassembled. Certainly, I'd be inclined not to try it unless a leak develops in future.

If the latter, again I would just build the tank as it's intended to be built, and worry about leaks if they occur later. If they do, I don't think the tank would even need to be disassembled; just drain, dry and then lay a sealing bead of something like the Geocel4500 or one of the other impressive sealants all around the interior joints, much as we typically do with glass tanks and silicone. This would only need to waterproof the joints; the sealant would not need to adhere so well as to hold the tank together against water pressure.

Either way...don't fix it if it ain't broke! Let's not assume that the tanks need any help at all; if they're built and designed properly, why expect them to fail? Would you buy a brand new all-glass tank, and immediately start stripping off or adding silicone and trying to re-seal it?

One last thing: I would not discount the possibility that applying any kind of sealant, silicone or otherwise, might interact chemically with the gasket material that the tanks already have. If that happens, you could be damaging the gasket, and ending up in a worst situation than you began.

I'm looking forward to hearing how this goes; good luck! :)
 
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