Silicone catalyst
Randy
10.1 oz. tubes. We want to do this so we can make it cure fast and all the
way through when we apply it real thick.
Please tell me what catalyst I can use. Thank you
Sculptingman
forget it.
These silicones are EVAPORATIVE cure systems- they turn solid as the
ascetic acid in them boils out {that vinegar smell)
Overall, silicone caulks do pretty good in curing up to a half inch
think, however,
if you make them TOO thick, the outer surface will cure and prevent
the ascetic acid in the middle from boiling out, so they will not cure
in deep sections.
Adding tin soap or platinum catalysts to them will have no effect on
the ascetic acid present in the mix.
If you need thick, caulk-like silicone that cures fast- silmply
purchase a THIXOTROPIC silicone from a supplier,(thixotropic silicone
bases are like peanut butter in consistency) and add Ultrafast
catalyst to it. 10% utlrafast will cure thixotropic silicone in
minutes- OR better still, you can vary cure time from minutes to hours
by mixing utrafast catalyst in varying percentages with ordinary
catalyst.
I use G.I. 1000 from silicones incorporated-
It is a normal liquid silicone body with a high tolerance for sulfur
and other compounds that will inhibit curing in many other silicone
products.
Along with the base silicone, I keep 2 different catalysts, 1000,
1020, which, each, yield a silicone with diifferent properties when
mixed with the same base.
I also keep on hand:
-a THIXOTROPIC ADDITIVE, which, when added to the G.I. 1000 causes
the mixture to become thicker and more viscous.
-an ULTRAFAST CATALYST- which I can add in varying amounts to finely
control curing time.
-CABOSIL- this is fumed silica, which I can add to the silicone with
thixotropic additive to get a silicone of any desired thickness, from
a very thick liquid, to a near solid putty.
_DILUENT- also called 'silicone thinner'- this additive lowers the
viscosity of silicone, making it more fluid so that in complex poured
molds the silicone will run thru the mold faster and with less
resistance.
With these additives I can have just ONE silicone in my shop, yet I
can mix a rubber with any consitency and curing time that I might
require. AND, I can buy the additives separately based upon the rate
at which I use them.
all in all, this system is the simplest, most versatile, and
productive.
christopher
"Randy" <rr...@netzero.net> wrote in message news:<1qIUa.121433$Io.10...@newsread2.prod.itd.earthlink.net>...
Dan S
damp surfaces and rub wet finger over the applied bead.
Dan
Will
The silicone thinner...
We used to use a citrus based solvent called D-Limonene to thin our
silicone. Is this the same stuff as your thinner or did the powers
that be finally come up with a proper thinner?
All the best,
Will
Dan S <arch...@earthlink.net> wrote in message news:<BB534347.1CBB1%arch...@earthlink.net>...
Sculptingman
> The silicone thinner...
> We used to use a citrus based solvent called D-Limonene to thin our
> silicone. Is this the same stuff as your thinner or did the powers
> that be finally come up with a proper thinner?
> All the best,
> Will
Never heard of the citrus solvent trick, Will...
Whats the down side? what percentages ? (never know when you need to
pull a rabbit out of a hat)
most reputable silicone formulators will offer a full range of
additives, from pigments, to various catalysts, to thickening and
thinning agents.
Some call it Thinner (like silicones, inc.) while others call it
diluent.
Technically, a thinner should be a vehicle that BOILS OUT, whereas a
diluent is an agent that becomes part of the compund or catalyzed
material.
The most common is a dense silicone "oil", that actually catalyzes in
the mix, although it does slightly lower the tear strength of the
resultng rubber. This oil is similar to the stuff that, with a
solvent, comes in "silicone release agents" that is, those release
agents containing a silicone, not those intended to SEPARATE silicone.
Some silicone rubbers will "weep" silicone oil after curing if it is
used in too high a percentage.
ususally, it is inadvisable to exceed 5% "thinner".
Only use it when you really need the silicone to run more easily, or
if you are filling a very large mold and you need the silicone to run
a good distance.
Thinned silicone has an even lower surface tension, and will allow the
silicone to flow down the capillaries of wood, sometimes several
inches.
> Dan S <arch...@earthlink.net> wrote in message news:<BB534347.1CBB1%arch...@earthlink.net>...
> > I have been told that moisture makes tube silicone cure fastest. So apply on
> > damp surfaces and rub wet finger over the applied bead.
> > Dan
Humidity helps with most catalysed reactions, but not with evaporative
ones.
paint is an evaporative system, and on a humid day can take twice as
long to dry.
Tube silicones rely on the slow evaporation of the solvent from the
surface of the rubber- anything coating the surface will inhibit
evaporation, as will air that is already saturated to capacity.
For tube silicones, leave them dry in a ventilated area. Try not to
accelerate the cure, as you may end up accelerating the cure of a thin
section of the surface, sealing off the interior mass from
evaporation.
christopher
slst...@ttc-cmc.net
with water before applying. Dip your fingers in water with just enough dish
washing detergent to keep it from sticking to your fingers and lightly pinch
the silicone between your wet fingers for a while to make a putty then apply
it to the sculpture. I've also squirted a bunch of silicone into the soapy
water and pinched a little out at a time and lightly pinching it between my
thumb and fingers.
Good Luck
Steve L.
"Sculptingman" <scul...@tfb.com> wrote in message
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