Mythbusting – Silicone

BushFishRox

Jack Dempsey
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Jul 7, 2007
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oscarluvr;2003151; said:
bfr i tend to agree with you, however how much time are we speaking of? silicone is not bio degradable, at the worst all it will do is shrink. for myself i will still clean away all excess (old) silicone before applying new, i do not want water on my hardwood floors.
probly just a week or two, it is really the water that does all the work because it likes to go where ever it likes which will cause the separation... I have even see water travel up hill so to speak by its self.
 

Horiyoshi III

Jack Dempsey
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How about this myth chomp.

A tank left dry to long will have dry rotted or cracked seals.So keep water in it to keep the silicone pliable and supple.
 

BushFishRox

Jack Dempsey
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Largemouthbadbass;2003540; said:
How about this myth chomp.

A tank left dry to long will have dry rotted or cracked seals.So keep water in it to keep the silicone pliable and supple.
it really depends on how the tank is stored. If it is kept in either dry heat or freezing condition then that could compromise the silicone, it is best to store tanks at room temprature...

otherwise a lot of aquarium stores would have useless stock, since a lot of their tanks sit around for a long time...
 

gomezladdams

Polypterus
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Sep 8, 2005
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Im less convinced by this one.Ive sealed acrylic sump baffles with silicone and while the initial bond looked good,the seals failed in a few months.
As for sticking to old silicone,even if the initial bond looked good I would worry about failure in a short time.The extra hour or so it would take to strip the tank is worth the peace of mind to me.

As for old seams drying out,I think its after tha tank has been filled with water for some time then dry that you see that.The most blatant example for me was a used 15g I got at a garage sale that held water for about a month then leaked.When I drained it the entire seal pulled away from the glass in one piece!
 

CHOMPERS

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Apr 28, 2006
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Dr Joe;2003482; said:
Keep up the good work CHOMPERS.

The old tank test will help further the results.

Silicone a piece of PVC to the old tank seal to pull against.

Did you hear the myth that if you give 5 live arowanas http://en.wikipedia.org/wiki/Arowana to a person who's screen name rhymes with rocter roe it will help with you in further experiments :D.

Dr Joe

.
That's a good idea about the pvc. I don't have five arowanas but I have a dead stinky one that I can dig up. So who is this Asian Doctor? :grinno:
 

CHOMPERS

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Largemouthbadbass;2003540; said:
How about this myth chomp.

A tank left dry to long will have dry rotted or cracked seals.So keep water in it to keep the silicone pliable and supple.
I have three tanks that will be good candidates.
 

oscarluvr

Feeder Fish
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Nov 26, 2007
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chompers you are doing great, insurance co's have crash test people for cars, maybe you could get set up to test for homeowners ins. for water damage due to failed silicone. lmao just kidding of course, i sincerely applaud you for your efforts thus far
 

WyldFya

Baryancistrus demantoides
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Dec 23, 2005
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Something I'd like to see in your next test, would be a fish scale (with a hook) attached to a pair of pliers, and then pulled against the fish scale. This will prove both the myth in question, and exactly what poundage they failed at.
 

chesterthehero

Feeder Fish
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Jan 20, 2008
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Largemouthbadbass;2003540; said:
How about this myth chomp.

A tank left dry to long will have dry rotted or cracked seals.So keep water in it to keep the silicone pliable and supple.
ive got a 60g thats been sitting in my backyard for a few months.. it was in someone elses backyard before that... its been around 100 for atleast a month.. whenever i have room for the tank ill letcha know if i need to reseal it or not..
 

WalterMelon

Feeder Fish
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Jul 23, 2008
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Silicone adheres to most plastics, but not all. It will not adhere to acrylic.

from the DAP 100% Silicone Technical Data Bulletin
( http://www.dap.com/docs/tech/00000683.pdf ):

"· Not recommended for use on cementitious materials or surfaces that might bleed oils, plasticizers or solvents. Substrates made of *methylmethacrylate, polycarbonate, polypropylene, polyethylene and **polytetrafluoroethylene do not allow for best adhesion and compatibility with sealant. Try test area before
using.
· Not recommended for use on brass, copper, magnesium, zinc, iron, galvanized metals or other surfaces
prone to attack by weak acids."

*methylmethacrylate is Acrylic
**polytetrafluoroethylene is Teflon
Silicone adheres just to fine to PVC, which is of course not on their listof non-recommended materials.

The silicone will work alright on acrylic as a gasket, but not as glue or in situations where it will be under pressure.
 
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