Casting Question

Darkov · Post by **Darkov** » Sun Aug 27, 2006 2:38 pm

Ok...I need some advice on how to cast this part.
Pic01
Pic02

I want the part to be hollow...to keep the weight down.
I have a vacuum chamber and a pressure pot so I'll be pressure casting one I finally get a mold that works.

Any advice will be greatly appreciated.

Pete

Stu Pidasso · Post by **Stu Pidasso** » Sun Aug 27, 2006 4:56 pm

If you want it hollow, you gotta cut it lengthwise in half. Good luck.

Post by **TER-OR** » Sun Aug 27, 2006 8:33 pm

The "seamless suckers" and such have long, hollow cylinders. Close one end as the top, and your mold will have a long cylinder of silicone. THose side holes will be a problem, though. If those are important, you'll have to make do with markers or go with a half-piece mold as The Jimi indicates.

Darkov · Post by **Darkov** » Mon Aug 28, 2006 12:22 am

Let's say that the side holes aren't there yet. I understand the "seamless sucker" concept. But how would I get the part out of a mold like that? I mean it would be a 4" tube within a tube.

Something like THIS

macfrank · Post by **macfrank** » Mon Aug 28, 2006 11:32 am

Darkov wrote:Let's say that the side holes aren't there yet. I understand the "seamless sucker" concept. But how would I get the part out of a mold like that? I mean it would be a 4" tube within a tube.

Something like [url=http://i56.photobucket.com/albums/g173/ ... aphic1.jpg]THIS[/
url]

RTV is pretty flexible, and unless you're making a bucketfull of parts, the mold should stand up to the flexing and finessing required to remove the resin out of the mold. One you remove the inner RTV core, you can use a dental pick or even an exacto knife to grab onto the resin and yank it out.

For the side holes, you can place some take on the inside of the tube when you make a mold of the exterior.

Frank