Thread: Help!! with my silicone skull mold..

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Ok, I spent hours upon hours gathering info/reading to do this. I filled the undercuts of my budget bucky skull with non drying clay. I bought GE I 100% silicone caulk.

I mixed 50/50 dish soap with water. I sprayed my skull with pam first. I put on nitrile gloves. Dipped them in the soap water so the silicone would not stick to them.

I started to squeeze the silicone into a cup and scoop out and slather on the mold. Almost instantly it turned into a cottage cheese like substance. It did not spread evenly and just clumped up. It had a hard time adhering to the skull.

Any ideas on what is going on? Should I not use pam?

I'm afraid I'm of no use when it comes to using caulk for molds. But, I've had terrible luck with pam as a release agent on molds.

I'm a little dubious of the reports of using caulk as a mold material, however. I don't know if it reacted with the pam to make this 'cottage cheese' or not...But, you are going to need SOMETHING as a mold release. You could try the mold release spray available at your local Michaels.

Well, is it a plastic skull? You might not need anything if it is...

I'm no expert, but maybe you could try the mold release and then use a cheap brush to apply the silicone instead of soapy gloves. The water/soap mixture may have been what caused the silicone to clump up on you. Just a thought...

I'm pretty sure the bucky skull is plastic.

Yeah, I'm going to retry today. At first, I didn't want to use a brush because I had clay in the undercuts, eye sockets, etc. I didn't want brush strokes in the clay. I think I'll do little sections at a time different ways and see what happens.

i was under the impression that the only thing silicone would stick to is silicone,, so no mold release was needed to remove the silicone from the skull,, im just getting into the mold stuff but thats what my research has come up with...

"Another issue with silicone is its adhesive properties. It is one of the stickyist substances in its liquid form. once it is cured however there are few things that it will stick to.
this is why when working with liquid silicone I use dish soap diluted with water to move the silicone around."

http://www.taxidermy.net/forum/index.php?topic=39157.0

...though I did not see it was very sticky in my first go around.

I have done silicone molds and they work great. I followed this http://www.taxidermy.net/forum/index...c,39157.0.html

Yeah, I just did a test. That's what I was doing wrong. The soap/water mix is last.

I did 2 quarter sized drops as a test. One on the skull plastic part and one on the clay part. No mold release.

1st just spread out the caulk. It is sticky but I moved it around with my gloved hand (no relation to michael jackson). Then, dipped my glove in the soap mix (very a little soap). I smoothed out the caulk. Let it dry for like 15min. It pulled right off with all the detail. YEAH!!

Now, time to do the whole thing. Might be tricky cause looks like this stuff dries quick!..

I got another question about reinforcing the silicone. Since silicone can tear easy.

I know the 1st layer of silicone is the detail layer. How long should I wait for that layer to dry before putting some cheese cloth on it?


...and Should I not let the silicone dry fully before adding the next layer? Should it be a little tacky to actually adhere to the next
layer?

If I were doing it, I'ld press the cheese cloth into the second layer as I was smoothing that out. Keep in mind not to cheese cloth the undercuts that you actually need to stretch. I would also think you would want it still tacky to add the second layer.

But again, I'm not a silicone caulk person. I am curious to see how it turns out.