Tin or Platinum Cure Silicone!

[RogueTrooper]

I’ve always used tin cure silicone like ultrasil, but I’m trying a platinum cure silicone, what do you think? Advantages, disadvantages? I’m hearing that the platinum silicone can get more casts than tin cure.

The cure time is super fast, that’s what I found so far compared to tin cure.

 

[robn1]

There are a lot of advantages to platinum, faster cure, longer life, some have 1 to 1 mix. But my experience has been that it has compatibility issues, not just with sulfur but some paints too. I use Tamiya spray, or sometimes lacquer on my master parts for a smooth finish, but every platinum silicone I've used took longer to cure against it. Smooth Sil 945 is a 6 hour cure but it takes 72 hours on parts with Tamiya or lacquer.

I've been using Mold Max XLSII tin cure with no problems. It's 10 to 1 by weight and needs 24 hours but that's better than 72. And mold life seems to be the same. Just stick with the higher quality tin silicones and it's not much of a problem.

 

[RogueTrooper]

There are a lot of advantages to platinum, faster cure, longer life, some have 1 to 1 mix. But my experience has been that it has compatibility issues

Thx for the response...

Are you saying that a resin cast from a platinum mold will create paint adhesion issues??

My research tells me that is incorrect, but I could be misinterpreting your information.

 

[robn1]

Thx for the response...

Are you saying that a resin cast from a platinum mold will create paint adhesion issues??

My research tells me that is incorrect, but I could be misinterpreting your information.

Sorry. no. I mean that some paints will affect the cure of the platinum silicone. I've made master parts from wood and plastic that I painted then molded. The platinum silicone took three days to cure completely because of the paint. Some resins will also affect the silicone, which will be a problem if you need to make molds of resin parts.

Tin silicones don't have these compatibility problems.

 

[swgeek]

Just depends on what you are doing. Some clear resins need to be cast out of a platinum mold. One down side to platinum, is that it doesn't react well with moister. Can be a problem depending on what you are molding and where you live.

 

[RogueTrooper]

The only problem I've really had so far with platinum silicone is that it sets incredibly fast, but the way to combat that especially on big pours is to still pour small amounts and build up a few layers to get the overall mold done. Silicone sticks to silicone like nothing else. I'm yet to cast resin from the molds, but it's the same brand and range as the silicone, so hopefully there will be no compatibility issues.