White RTV mold compound

I am in search of a white rtv mold compound that I have seen from
only one manufacturer. International Manufacturing from Philadelphia
used it years ago, but I can no longer find that compound. It had a
nice feel (pretty soft actually), but it did not tear very easily.
We have been experimenting with dozens of mold compounds and I have
yet to find the “perfect” one. If anyone knows where we can find the
white compound, or has any suggestions about their favorite
compounds, please pass it along. At this point I am only interested
in the RTV type.

Jason Kresge
Vice President
Lineberry & Company

You might try Dow Corning’s HS II. Had some shipped to me by
mistake, it was white and quite low durometer.

Take a look at

It lists all of Dow’s RTV materials. Personally I prefer the
Silastic J.

Good luck with the search.

try this place

Good luck

Hi Jason:

If you are looking for high tear strength silicone RTV and not just
white color, please check our web site. Our silicone is clear, but we
can provide a white colorant if need be. At one time many years ago,
we did offer it in white and that may be what you saw in
Philadelphia. Now we offer a white colorant which can be added if you


Bill Mull
Zero-D Products, Inc.

This is Michael Knight at CastaldoO.

We have a new RTV mold compound that you might be interested in,
even though it isn’t white.

We call it LiquaCast Ultra because it is an improvement on our
standard LiqaCast RTV rubber.

It’s INCREDIBLY strong & tear resistant. It flows almost like water
( about the consistency of cream, so it’s easy to pour, mix and
de-bubble) It’s too new to say for sure, but so far it seems to avoid
the problem that some RTV molds have of getting softer over time.

Oh - color? It’s orange!

Please see the attached file for more details. attachment

I’d be happy to send you a free sample if you give me your contact
and shipping details – no PO box please.

And I’d be happy to send free samples to anyone else out there who
is interested.

Michael Knight

I wish to clarify something relative to RTV compounds. There are
many of differing chemistry. RTV is a general term and only refers to
the room temperature cure capability, not the chemistry.

Polyurethane RTV tends to revert to liquid over time, especially in
moist regions. This accounts for the sticky, useless molds some folks
end up with after using some of the less costly polyurethane RTV

Platinum cure Silicone RTV makes a permanent mold. In addition,
silicone RTV does not contain any mercury compound such as is found
in some of the higher tear strength polyurethane RTVs.

Read the M.S.D.S. for the product you are using.

I think it is important that you first determine whether you wish to
buy silicone RTV or polyurethane RTV.


Bill Mull
Zero-D Products, Inc.

Dear All,

This is Michael Knight at Castaldo.

Bill Mull brings up a good point, one that I’ve made many times

While it is too early to tell, our new LiquaCast Ultra gives every
indication that it will not become soft and of lasting a long, long
time, even in moist climates.

Michael Knight