Making a two part silicone mold; release doesn't work?

[GotWookiee]

Alright, I've been trying to make a two-part silicone mold with Oomoo 30.

It's my understanding that I can use Smooth-On's universal spray release to keep the two halves from sticking together. This is what they use in Smooth-On's on videos showing how to make a two part silicone mold with Oomoo.

I've tried it twice and it has failed to work both times. The first can was several years old so I figured that was the problem. So I tried again with a new can and the result is the same.

I put plenty on, brushed it around into every nook and cranny. The two halves stick together perfectly, as though they were put on at the same time from the same batch.

I bought some of my smooth on products from a local art supply store (Plaza in Nashville) and it's possible the release was already in stock for a long time. There is no way to know, however, as Smooth-On does not list the shelf of their products nor provide a date of manufacture on them.

What are some alternatives? Vaseline? Tincture of Green Soap, 50/50 dish soap?

Suggestions?

 

[Fyberdyne Labs]

You should check if the spray release is silicon base if it is it may not work. If it is petroleum based it should work. I useally use vaseline. But anything that keeps the silicon from bonding to the other side will work. As long as it doesn't interfere with cure of the silicon.
Hope that helpes!
Mark

 

[ultraman]

yeah i'm with fyberdyne labs i also use vaseline with q-tips and have never had a problem

 

[TerryMcIntosh]

While I'm a noobie at such things and have only now tried it twice with simple test objects, I do recall that the only thing silicone will stick to is silicone, so I'll echo what the others have said... make sure that your spray is not silicone-based and you should be golden.

 

[GotWookiee]

Cool. Thanks, guys. I'll give that a shot tomorrow.

 

[ultraman]

hay gotwookiee
feel free to post what it is you're casting....i'd be interested to see whats going on! the more we know, the more we can help out with ideas here and there about your casting process. we're all here to help each other out!

 

[auzorann]

i've always used ease release 200 and it always works. the can i have now is probably 2 years old and it still works lol.

 

[Streetrocks]

To echo the above statement, I have used ease release 200 with oomoo and had zero problems. The oomoo on the other hand, I am really not a fan of.

 

[Gorgot3000]

rebound 25 is better than oomoo30 .... for release , 2 part 100% alcohol ,1 part dish soap .I didn't try it but this is what the owner of my local smooth on reseller told me.

 

[TheBrothersRich]

I have made a stupid amount of multi-part silicone molds and petroleum jelly does the trick every time. I apply with a brush and wipe excess away so just a fine layer is left.

 

[ColinWily]

Smooth On's Universal release is silicon based.
Ease release 200 or 205 is a non silicon based release agent.
Ease release 2831 will be required to release polyurethane from silicon - as I learned this week after destroying two silicon moulds.

Or use the various other tips here which are more cost effective.

 

[Charles Barnard]

.. it's possible the release was already in stock for a long time. There is no way to know, however, as Smooth-On does not list the shelf of their products nor provide a date of manufacture on them.

Smooth-on products have a shelf life at room temp of 1 year.

If you email them the batch numbers they can and will tell you the date of manufacture and approximate remaining shelf life (Just did this with some I purchased on eBay.)

As with everything, shelf life is an estimate, and may vary due to actual storage conditions, YMMV Stored in stable temperatures it will probably remain usable for some weeks or months after the expire date, but such use should probably be limited to non-critical projects for the obvious reasons.

 

[wolfchild59]

It sounds like you might be using the mold release. Made to be sprayed in the mold when making a cast, not releasing silicone from silicone. That's this product: Universal Mold Release® Agent Product Information | Smooth-On

I believe what you need is this: Mann Ease Release® 200 & 205 Product Information | Smooth-On

Personally, I use Alumilite silicone with Smooth-on resins, so I use the Alumilite silicone to silicone release. But I did use Vaseline once in a pinch, when I was out of the release and it worked just fine.