[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: KillieTalk Digest V2 #172
Hi, All,
I agree with all YoHoHo said about silicone sealers (KillieTalk Digest
V2 #172), except that part where he says that it takes two months to
cure a resin formulated with methyltriacetoxysilane (i.e. which evolves
acetic acid upon curing).
While there probably is such a resin, the two brands of "aquarium
silicone sealant" that I have used, both were cross-linked with
methyltriacetoxysilane. They cure in about 24 hours and can be used as
soon as the acetic acid (vinegar) smell goes away. That does not take
more than 2-3 days, depending on temperature, humidity, etc. Thus the
reason for a long cure of a particular silicone resin can NOT be due to
the cross-linking agent methyltriacetoxysilane.
The prudent fish keeper would age a new tank, filled to the brim, for at
least a day, or two, to be on the safe side. The small traces of acetic
acid still left in the silicone resin will diffuse out over time, but
will not harm the fish: A drop or two of vinegar in a tank of water will
have no effect on pH or the fish.
I have not seen any of the inexpensive silicone sealants with a "safe
for aquarium use" comment, but I have seen notices "not for aquarium
use" or "not to be used where FDA compliance required". They contain
something noxious.
If you want to experiment with an inexpensive silicone sealant, try the
GE "Window & Door" sealer. There are *TWO* kinds, both GE brand: One
says "Silicone" on top - that's the good guy, the other says "Silicone
II" - stay away from it. They are about $3 for a regular caulk size
cartridge. If you use them, please report to the list.
One can not overemphasize YoHoHo's warning about "mildew resistant"
formulations. Years ago, GE used an arsenic compound for this purpose
(no wonder it killed fish!). Now they (and other manufacturers) are
hiding behind "trade secret" and give only a chemical registry number.
It is easy enough to look it up - but why bother? STAY AWAY from brands
that hide their components behind a "trade secret" label! (The only ones
that do not know what that "secret" is are the consumers. The
competition has figured it out long ago!)
Best,
George