Question about casting SmoothOn polyurethane RUBBER...

Lt. Z0mBe · Post by **Lt. Z0mBe** » Mon Oct 08, 2012 8:12 am

Wise and Sagely Starship Modelers,

I have an odd question about casting SmoothOn polyurethane rubber. Can SmoothOn polyurethane rubber be cast using their RTV silicones as molds? I figured if their polyurethane resins can be cast using their silicones, there's a good chance the rubber could be molded the same way.

I know I can make molds other ways. I'm just curious about the viability of this potential method.

Any advice is appreciated, as always.

Kenny

Joseph Osborn · Post by **Joseph Osborn** » Mon Oct 08, 2012 8:52 am

Yes, it can. I'm going to be casting parts from Smooth-On Reoflex rubber in silicone molds later today.

Blappy · Post by **Blappy** » Mon Oct 08, 2012 9:06 am

Huh! I have never even thought of doing this. I guess I have never needed to. What mold release do you use?

Joseph Osborn · Post by **Joseph Osborn** » Mon Oct 08, 2012 11:21 am

Good old Mann 200.

Stu Pidasso · Post by **Stu Pidasso** » Mon Oct 08, 2012 11:23 am

Whatcha doin', Kenny?

Lt. Z0mBe · Post by **Lt. Z0mBe** » Mon Oct 08, 2012 2:14 pm

Stu Pidasso wrote:Whatcha doin', Kenny?

I came up with some simple tools and figured I'd try to make a few. Specifically they're some sanding blocks and wedges. If they turn out well, I might sell a few to my brother in law; he is a carpenter who builds...no crafts really nice furniture by hand and needed some really specific stuff.

Nothing sexified like E-Wings and Vipers I am afraid...

Thanks for all the help guys! I get to use up my last batch of stuff instead of just letting it go bad for a change.

Kenny

Michel007 · Post by **Michel007** » Wed Oct 10, 2012 11:31 pm

...Spam...

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Thu Oct 11, 2012 1:13 am

I cast polyurethane rubber in silicone molds all the time.

http://myplace.frontier.com/~aimee.eng/id12.html

Thought about doing the APC tires.
but then I would have to separate the wheel and tire/tread...

chasd25 · Post by **chasd25** » Fri Oct 12, 2012 9:34 am

We cast flexible urethane elastomers in silicone molds all the time. I've never used the smooth on flexible urethanes. I believe they have some that will work in Tin based silicones though.

We mainly use the BJB stuff at the shop. Great stuff, and available in just about any durometer you need. It does however need to be cast in Platinum Silicone molds. We also cast them in machined acrylic molds quite a bit as well.

We just finished a project molding, and casting a translucent, flexible life size stomach using one of the BJB waterclear flexible urethanes.

We use either Mann release, or Freekote 1711

Charlie

Lt. Z0mBe · Post by **Lt. Z0mBe** » Fri Oct 12, 2012 11:24 pm

Thanks guys! You all are a fountain of knowledge. I cast a few very small 70 shore polyurethane rubber wedges (keeping a few for myself

) and they came out without a hitch.

Kenny