Heating up RTV molds

[ram3139]

I'm just starting out in pouring soft plastics. I made a mold of a 3" minnow style bait that has a thin tail section. I was having trouble getting the plastisol to flow all the way into the tail, even with small vent holes cut into it. I figured the plastisol was probably cooling down before it flowed all the way in, so I heated up the mold in the microwave before pouring it. That worked a lot better and the bait came out well. My question is, will repeated heating of the mold in the microwave cause any damage to it? Is there a better way to heat it up, or a better way to get thin sections to pour well? Thanks in advance for any thoughts.

[dahlberg]

no prob heating the mold. we do it all the time to speed up curing of both flex and clear hard plastic as well.
If your mold starts to dry out a little you can refresh it with a little silicone oil.
best
L

[Shaane]

Still learning myself want to try this. How long are you heating the mold in the microwave. 20 30 seconds or longer thanks

[dahlberg]

depends on the power of the mike and the size of the mold. Usually just heat until med warm. Not too hot to handle.
Usually takes a minute or less.
L

[Mike - Alumilite]

A rule of thumb is 1 minute on high per lb of silicone rubber gets you to a nice warm temp. Obviously, mics vary as Larry stated so test is best.