reinforced RTV ?

[raalst]

Hi all,

I am making an RTV mold, and it occurred to me that I might save RTV
if it would be more tear-resistant. Then a thinner layer would suffice.

To test this approach I put a bit of glassfiber cloth (woven) into a patch of
RTV. it is curing now.

Did anybody try something like this before ? results ?

[mylo]

Ronald,

I never tried anything

Ronald,

I never tried anything like that, but am very interested in how your experiment turns out. I find the RTV that I use from Smooth-On to be very tear resistant, I never had any issues with that, even in very thin layers, ....stuff is NOT cheap though.

Mylo

[raalst]

It worked very nicely. the

It worked very nicely. the stuff was still flexible but no longer
stretchable.

the only thing to note is that while the RTV got through the cloth,
the remaining connections between the two sides are a bit on the
flimsy side (not to say microscopic)

So, If I can find less-tightly woven cloth, I am going to try this full
scale (but not on my current build..)

[mylo]

Ronald,

So, did you apply

Ronald,

So, did you apply a layer of RTV to your test plug, let that cure, lay down the cloth, apply a layer of RTV over that, let cure ? .....and is what you are saying that the layer of RTV applied WITH the cloth didn't adhere to the initial layer of RTV as well as expected ? ....or do I have your explanation all wrong ?

I don't see where the RTV no longer being stretchable is a concern. In fact, I can see where that is beneficial, so that it doesn't get distorted or stretched out of shape somehow over time.

Mylo

[raalst]

I did take a bit

I did take a bit of planking, put up a rim of paraffin and put 4 little bumps
of paraffin in the middle to simulate some detail.
hen the glass was put on top of the bumps. next I dabbed some silicone
onto the glass.

what came out was a flat square bit of silicone rubber, only with an
air pocket trapped underneath the glass between the bumps.

Some very small drops of silicone had leaked through the glass into the
air pocket. It showed a nice pattern similar to the glass on the planking.
This way I know the silicone can get through the glass.

I could now try to pick the silicone from the glass at the rim of the air pocket
and I could tear the silicone from the glass. This means not enough contact
is made through the glass to fix the upper and lower silicone layer together.
But a less tightly woven glass would fix that.

I too am happy with a no-stretch material, because stretching means
danger of tearing. the Glass cloth prevents that, so no tearing even when the layer is thin (as in silicone/glass/silicone)

The resulting plate of rtv was about 2 mm thick, btw.

I have to scrounge some batteries before I can take a picture....
stay tuned.
<scrounging complete>