Alumilite Mold Debonding question (it's in there somewhere)

[cnirenberg]

Ok, I have a touch of the casting bug at the moment and have come across a question for all of the casting guru's out there.

Here is the background info: I recently got some Alumilite white and wanted to cast a solid rod for a kitless pen. No problem. I measured the amount of A and B required to fill the mold I.D. I used a 6" clear pen tube, like the kind one puts a finished pen in at a show, as the mold. I wanted to be able to see though it so that I could gauge how fast/slow to pour it in as not to get and bubbling (no pressure was applied..this time). I coated the interior of the tube with paste wax (thanks Mike at Alumilite) and went to town. The tube is fairly thin and must have attached to the cast due to excessive heat generated. No problems, I just turned the clear tube off when it cured-it basicaly was a throw away.

Now here is the question. If I want to use a PVC/Copper mold, when can I de mold the casting without it sticking to the mold? I would like to reuse the mold and cast a longer rod. Any help or direction would be greatly appreciated.

 

[NewLondon88]

I think a regular mold release is a good safe bet. (something like Stoner)
but you could also coat the inside with vaseline. Some say that with PVC
you don't need any release, but I had a lot of difficulty getting it to de-mold,
and the longer the tube, the more trouble I had. So I would use a release
anyway.

 

[LandfillLumber]

I have used mineral oil in PVC with urethane resins works well.I do it like cleaning a gun I use a long parts grabber and attach a small piece of rag that has been soaked in mineral oil(pat dry so you won't have some much on your hands and everything else).Good Luck,Victor

 

[cnirenberg]

Thanks,
I stumbled upon a post by Mike at Alumilite and he siad to try coating the inside of the mild with baby powder to help eliminate any bubbles.. Wondering how that would work with the Vaseline?

 

[NewLondon88]

The baby powder works ,no question. Think of it as a bunch of tiny needles poking
the air bubbles. Talc is, after all, an abrasive. But I haven't tried it with vaseline