New Custom Built Aquarium Silicone Curing Time?

[Marine_PJ]

Hi, it’s my first post here – was hoping someone could provide me with some guidance …

I recently ordered a new custom built tank (5x2x2 – 110g) & sump from a London based manufacturer, which was delivered last Friday (13th!). It was to replace my 75g tank which I managed to sell privately and was picked up today; hence I had 3 days to transfer all livestock and rock over to the new setup.

First I fitted the bulkheads and also cemented all the pipe work and left it to dry for 24 hours. I then filled the tank with mains water and let the pump run for an hour to check that everything was ok and there were no leaks. Everything was ok …
Next day I filled up the difference with RO water and transferred everything over from the old tank - however when I was fitting the lid I noticed a little sticker on the inside of the tank saying – ‘tank to be used after the 21st of January’!!!

I rang up the manufacturer and asked them why? Apparently the tank was made on the 9th of Jan and they recommended that the Silicone needed time to cure before use. I was a bit confused why I wasn’t told explicitly to begin with as I had previously told them that I would be transferring the content of my old tank immediately? They said I could probably fill up slightly less than half the tank to reduce the pressure and allow the silicone time….

I have read on the Internet that it only takes a few days for the silicone to cure – is this correct? So it would have been 4/5 days the silicone on the tank had to cure – there was no vinegar like smell.

There were no leaks – does that mean no damage has been done? I have reduced the water level to less than half and put a pump circulating the water around the live rock and the fish seem ok. I’ll wait until 21st to fill the tank fully.

Any information would be appreciated to put my mind at rest - I have children around the house - don't want the silicone to fail or worst tank breaking apart

Thanks in advance.

PJ

[jimmy frag]

was the tank built in your home or was it delivered ? if it was built in the manufacturers facility I cant believe they would ship a freashly built tank out to a customer with a sticker saying do not fill before.... wow.

[Marine_PJ]

Hi Jimmy - The tank was built off-site at the manufacturers.

Regards

PJ

[Saltydrip]

That's crazy!!!!

At my work we us silicone in several different applications. A typical finger spooged bead should be dry dry in 36-48 hours. The bigger the bead the it can take WAY longer! If it's the typical amour as seen on most store baught tanks I would say your fine. If they have it really loaded in there I would wait to put more water in there.

Pluss you should be able to press on the silicone and see if it is soft.

[kuyatwo]

The outside of the silicone might be cured but since it is winter time and it is colder the inside of silicone will take time to cure thoroughly


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[Saltydrip]

It won't be Ferm feeling until it's dry inside too. The problem with a thick bead of silicone is that it needs to offgass to cure. The outer most bit get the most air so it will dry quickly. And the middle will not be able to cure for some time because the gasses can't escape and need to work there way out with time. It will feel dry to the touch but still be squishy when depressed. If you do feel it necessary to press on it to see if it is dry, do try it in an inconspicuous spot. As not to make a low spot in the silicone forever.

[uncleof6]

Originally Posted by Marine_PJ

Hi, it’s my first post here – was hoping someone could provide me with some guidance …

I recently ordered a new custom built tank (5x2x2 – 110g) & sump from a London based manufacturer, which was delivered last Friday (13th!). It was to replace my 75g tank which I managed to sell privately and was picked up today; hence I had 3 days to transfer all livestock and rock over to the new setup.

First I fitted the bulkheads and also cemented all the pipe work and left it to dry for 24 hours. I then filled the tank with mains water and let the pump run for an hour to check that everything was ok and there were no leaks. Everything was ok …
Next day I filled up the difference with RO water and transferred everything over from the old tank - however when I was fitting the lid I noticed a little sticker on the inside of the tank saying – ‘tank to be used after the 21st of January’!!!

I rang up the manufacturer and asked them why? Apparently the tank was made on the 9th of Jan and they recommended that the Silicone needed time to cure before use. I was a bit confused why I wasn’t told explicitly to begin with as I had previously told them that I would be transferring the content of my old tank immediately? They said I could probably fill up slightly less than half the tank to reduce the pressure and allow the silicone time….

I have read on the Internet that it only takes a few days for the silicone to cure – is this correct? So it would have been 4/5 days the silicone on the tank had to cure – there was no vinegar like smell.

There were no leaks – does that mean no damage has been done? I have reduced the water level to less than half and put a pump circulating the water around the live rock and the fish seem ok. I’ll wait until 21st to fill the tank fully.

Any information would be appreciated to put my mind at rest - I have children around the house - don't want the silicone to fail or worst tank breaking apart

Thanks in advance.

PJ

Unfortunately, the builder is correct. Minimum cure time (for the necessary cross-linking to occur) is 7 days. Longer is preferable. Anywhere from 7 - 14 days. This is past the time you would notice a "vinegar" odor. Spooged out silicone, for non pressure holding projects is irrelevant in terms of an aquarium. A failure, from insufficiently cured silicone, may not be apparent for a year or maybe two. Most info on silicone, concerns consumer grade silicones that are not intended as adhesives, rather sealants. Aquariums are not built using sealants, rather adhesive silicones. Completely different materials.

[Saltydrip]

7-14 days is a long time!!! That stinks.

I'm in composites and we bond our molds/tooling to it's supporting structure with silicone and a big fat bead usually take 2-3 days to be totaly dry. Granted it is in a hot dry shop. Sometimes we are putting several hundred pounds of stress on that bond. Had it fail once though after about 30 hours. Had a 700lb carbon fiber mold crash to the ground. The boss no longer says "that "should" be dry"!

[Offalmangler]

That sucks. I have some stuff I could ship ya. Aircraft sealant. Don't think it would be too freindly for tanks though! We use it for some fabrication on aircraft. You could bond a house and drag it!!! Tough stuff.

[Saltydrip]

Originally Posted by Offalmangler

That sucks. I have some stuff I could ship ya. Aircraft sealant. Don't think it would be too freindly for tanks though! We use it for some fabrication on aircraft. You could bond a house and drag it!!! Tough stuff.

What stuff?? Pb bond? Plexus? What is it, what is it?!?!?

I love getting to take home "expired" materials!! I build all kinds of cool aircraft parts. Mostly interiors for all kinds of choppers. You?

[Agu]

When I made my own tank using Momentive RTV Silicone the manufacturers recommended minimum cure time was one week.

Although you probably used the tank too soon the silicone will continue to cure although at a slower rate because of the added moisture. If it hasn't failed yet I doubt you have risk of future failure.

[Marine_PJ]

Thanks everyone for your feedback - provides some reassurance.

The thickness of the silicone bead is normal to all the other tanks I've had in the past, so hopefully will be ok, but will wait until the specified date to fill up the other remainder of the tank.

Will the 300 litre (approx) mixed salt RO water I removed and had to store in a outdoor container be ok to reuse? Temp at night is about 2-8 degree celcius! - I'll make sure I put a heater and flow pump in it for the prior 12 hours to give it a good mix. So in total it will have been outdoors for 5 days.

[Saltydrip]

You will need a serious heater to get the temp up from 8c to 25c. Maybe you should bring it inside. 24 hours befor.