Uncured silicone will eat through the Liquid Rubber products (Zavlar/Pond Coat, etc). Most likely it ate through the liquid rubber and bonded to the wood and that's why it couldn't be removed.slimmer;3953527; said:
My 315G Plywood Tank Build
- Thread starter BadOleRoss
- Start date
I will be digging into the problem more today and will take a good look at the seal where the leak actualy occured. I have a test peice of wood, glass, plexiglass, PC that has been sitting around drying for a couple of weeks. I am sure that test piece is less then 15% moisture. I will get that it water and see how it reacts. Pete, I assume the moisture meter will be found with the plants? And any thoughts on etching the edges of the glass? One thing is certian, this has slowed me down. I was in a rush to get the tank filled, now I just want to make sure it doesn't leak the next time I fill it.
Hey just catching up on your post. Nolapete is right, your cure time wasn't long enough. I read where you said you "Jumped the gun." I think that was the problem. My success with silicone, pond coat, and other liquid rubber brands involved letting the silicone around the glass cure for a full week. I haven't had any issues with liquid rubber adhereing to glass and up over the silicone, as long as you let the everything cure well. I think this is your problem. Cure time for the liquid rubber ranged from a week to 14 days to fully cure. I'd be willing to bet that the cure time wasn't long enough either for the silicone OR most likely you filled the tank too soon with water and the rubber could not set up fully (the water neutralized the unfinished cure). But mostly likely I'd bet it all revolves around the cure time.
Is your work shop heated? I know that the cure time depends heavy on the temperture and humidity. I think 50F is the minimum temp for curing liquid rubber and requires around 2 weeks to fully cure. I've even timed tank builds for spring and fall builds because I'd have to apply coatings, epoxies, etc in an unheated-no a/c garage. Curing time for epoxies and liquid rubber in August himidity in the midwest is hell.
On another note, it is possible there could be the issue of the spacers you used between the glass and the wood. I'm not for certain because I have never used spacers before, but silicone squishing out was never a concern. Perhaps the silicone needed the extra crush factor that the spacers prevented.
1 more scenario haha, bare with me here, perhaps there was an issue with the wood surface that the glass is glued to, with regard to not being square, flush, plump, etc. Typically the silicone, which works as a gasket, will fix minor discrepancies, imperfections, flaws such as an unlevel surface. The problem again, could be the spacers, interfering with the silicone's ability to "fill the flaw" or gap, what-not.
(I grew up in an auto-repair shop, this was a constant problem with intake manifold gaskets. The front/back gasket worked more of a spacer, than a gasket. Once installed and engine running, the pressure would always build and blow out the front/back gasket. This was all because the front/back gasket worked as a spacer and took that much sealing power away from the silicone used to seal it. The solution? Throw away the spacers and just use silicone. This worked 100% of the time IF you let the silcione fully CURE! haha)
Ok I think the only scenario I didn't present is global warming. But serious, the cure time, Nolapete hit it on it and I 2nd it.
Is your work shop heated? I know that the cure time depends heavy on the temperture and humidity. I think 50F is the minimum temp for curing liquid rubber and requires around 2 weeks to fully cure. I've even timed tank builds for spring and fall builds because I'd have to apply coatings, epoxies, etc in an unheated-no a/c garage. Curing time for epoxies and liquid rubber in August himidity in the midwest is hell.
On another note, it is possible there could be the issue of the spacers you used between the glass and the wood. I'm not for certain because I have never used spacers before, but silicone squishing out was never a concern. Perhaps the silicone needed the extra crush factor that the spacers prevented.
1 more scenario haha, bare with me here, perhaps there was an issue with the wood surface that the glass is glued to, with regard to not being square, flush, plump, etc. Typically the silicone, which works as a gasket, will fix minor discrepancies, imperfections, flaws such as an unlevel surface. The problem again, could be the spacers, interfering with the silicone's ability to "fill the flaw" or gap, what-not.
(I grew up in an auto-repair shop, this was a constant problem with intake manifold gaskets. The front/back gasket worked more of a spacer, than a gasket. Once installed and engine running, the pressure would always build and blow out the front/back gasket. This was all because the front/back gasket worked as a spacer and took that much sealing power away from the silicone used to seal it. The solution? Throw away the spacers and just use silicone. This worked 100% of the time IF you let the silcione fully CURE! haha)
Ok I think the only scenario I didn't present is global warming. But serious, the cure time, Nolapete hit it on it and I 2nd it.
Oh I forgot in my previous rant to mention ruffing up the surface of the glass where the silicone is applied. I don't recall if you mentioned doing that. Just like anything else, it grips better to a rough surface than a smooth surface like glass. A simple scratching with sandpaper will rough it up just fine. If you do have to reinstall the glass, don't forget this step. Oh and don't wipe the sanded glass-dust clear with your hand haha. Been there, done that, and even knew better.
First, thanks for all the feedback and the absence of bashing! Cure time was clearly the issue! The tank is inside a heated room but there was still less than a week between the final coat of PC and the fill/leak. When I was pulling the PC off the glass last night I was getting the black PC on me hands, still pretty much wet! Uncured! My plan right now is to remove the unsure PC from the glass back to the wood frame and take a good look at the silicone seal and see where the failure is there and determine whether or not the glass needs to come out. Pulling out one piece of the frame to get the glass out will not be too bad, the other piece of the frame will have silicone left on it which will be a bear to remove, removing and replacing that frame as well might be required. Once I get the glass back in and siliconed I will let the silicone sit for a good week with a dehumidifier in the room to cure before I put on the PC, the PC will then be allowed to sit another couple of weeks for everything to cure up good. I tried to sand the glass edges earlier and the sand didn't scratch the glass at all, I am thinking about etching the adges, any thoughts? Am I just using the wrong sandpaper?
Surprisingly, even after a leak I am feeling very positive this bright sunny morning!
Zombie, there is no such thing as global warming!
Surprisingly, even after a leak I am feeling very positive this bright sunny morning!
Zombie, there is no such thing as global warming!
Yes, I had decided to remove the glass, frame, everything and redo that part of the build so I had nice clean materials to work with to get a good seal. I didnt want to put new silicone on old silicone and the best way to clean that up was to replace the frame. Well, it didn't go so well. As I pulled the top part of the frame away the silicone had a better bite on the glass then I gave it credit for. The wife (she who always must be obeyed) has given me the go ahead to order new glass on Monday and I have already removed the old frame and replaced it with nice new lumber. This will give me a chance to add more PC to the tank. I might make some call and see if I can find acrylic.nolapete;3954907; said:
