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.
Polymershapes 100% Silicone
- Thread starter Charney
- Start date
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.
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 thinkingI'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.
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
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?
Lol, anything else? A fresh clean aroma? Choice of colours? Maybe tastes good as a condiment on burgers or hot dogs?
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
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.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?
Lol, anything else? A fresh clean aroma? Choice of colours? Maybe tastes good as a condiment on burgers or hot dogs?