Platinum Silicone / Grey V4 - good results


#1

I printed small cups to test curing platinum silicone in parts form a Form 3. These results are specific to Smooth-On Ecoflex OO-20 and Grey V4 resin. Ecoflex OO-20 was chosen because Smooth-On support says it is one of the most sensitive platinums to cure inhibition.

After printing the test cups I did a 2 stage IPA rinse, then 2 hour cure with both heat (60 deg C) and UV. I waited 24 hours then did another 60C and UV cure for 4 hours. After this cure cycle the parts had NO odor whatsoever which I took as a good sign.

One test cup was coated with Inhibit-X (which helps to prevent inhibition) and the other left bare. I poured the rubber and left it for 12 hours. The rubber in the uncoated cup cured properly (have used this material a lot before so I have a good frame of reference). The rubber in the cup with Inhibit-X cured but also stuck and I mean STUCK to the surface. The Inhibit-X docs mention this sticking possibility and they seem to be correct.

Verdict - Grey V4 with extreme cure seems to play nice with platinum silicone. Different resins and rubbers will behave in their own manner of course. I think a specific test is the only way to know.


#2

Draft V1 results (same cure cycle as above):

Inhibit x - cured but again stuck to the point of being useless.
Uncoated mold - failure. Uncured silicone remained at the interface between the rubber and mold.

Even after the long cure the parts made from Draft V1 still had a slight odor.