Does anyone have a recommendation for a material to make a casting of the insides of a part?

I used to do this several years ago when making injection molded bottle closures. It was a two part, no shrink epoxy type stuff that we would fill a cap with. Then we'd cut the cap off and examine the casting of the threads.
Darned if I can remember what exactly it was.

Now I want to take a casting of a brass part to look at internal features so I need something that will release fairly easily as I don't want to cut the brass to get the casting out.

Any suggestions? I having a bad google day.

thanks

Reprorubber: I've used this product for years with good results.


http://store.flexbar.com/merchant2/merchant.mvc?Screen=CTGY_IM&Store_Code=FLX&Category_Code=Reprorubber

Reprorubber: I've used this product for years with good results.


http://store.flexbar.com/merchant2/merchant.mvc?Screen=CTGY_IM&Store_Code=FLX&Category_Code=Reprorubber

cool, thanks.

We use a product called Splash. It is a dental impression material. Contact a local dentist and see if he can get it for you. It is very handy as it has an applicator that mixes the product as you dispense it. Good Luck.

We use a product called Splash. It is a dental impression material. Contact a local dentist and see if he can get it for you. It is very handy as it has an applicator that mixes the product as you dispense it. Good Luck.

customer service manager's stepfather is a dentist... I'll check with her.

Repro-rubber or Facimile. Repro-Rubber isn't as nasty to work with as Facimile so it's generally the better choice. Used it for years with nothing but good results.

Both sold by Flexbar.

Repro-rubber
We use Repro-Rubber too. I buy it from J&L Industrial Supply but I'm sure it's available through many industrial supply companies.

Reprorubber: I've used this product for years with good results.


http://store.flexbar.com/merchant2/merchant.mvc?Screen=CTGY_IM&Store_Code=FLX&Category_Code=Reprorubber

That's really perfect.
Thanx.

I looked up the repro rubber in the J&L catalogue. It looks like it could get messy. The dental impression material we use is clean, quick drying, and we dispense only what we need with no guessing how much to mix. We use it on valve seats, shock valving, and a number of other parts.

The normal repro rubber is not messy at all. It starts out relatively thick, it will hold a fingerprint almost immediately. Repro-Rubber Thin Pour is obviously much thinner since it's designed to be poured into something.