HELP! problem wit mold breaking down!

[nick-a-tron]

need a bit of advice here guys. made of mold of a few items a few days ago using RTV silicone rubber and only after 15 or so pulls its gone really dry and is breaking apart! im using smooth-on 300 resin to cast the parts and parts of the mold are coming off as i pull out the resin pieces!

is there any way i can avoid this??

 

[robstyle]

Ive heard of "cooking" a mold to reinvigorate it.
Short of wax, once a mold breaks down, its done.
At least thats my experience.

 

[CustomCreations]

use a release agent to protect the silicone- also check the mixing ratio of the silicone as too much catalyst may give a brittle mold.
Also, it depends on how deep your undercuts are. Silicone is good- but 15 pulls of a heavy undercut thats thin/fraglie may be asking too much sometimes ;-)

 

[vaderdarth]

This one may be too far gone, but the key is once you make a new mould, use a good releasing agent to increase it's life span. Even doing so, it will eventually break down if there are lots of undercuts or even a few deep undercuts. It may be time to re-mould.

Dave