1/14 CAT 390D LME

[grumpygrady]

i have a few links about making sand molds to do what you need ,let me know if you want them ,
but the best way is doing lost wax and using a wax tree and casting thirty or more at one time in a investment mold ,
and by the way plaster of paris will cause a exploration of hot metal because you can't bake all of the water out of it .

[Jw.]

Originally Posted by grumpygrady

i have a few links about making sand molds to do what you need ,let me know if you want them ,
but the best way is doing lost wax and using a wax tree and casting thirty or more at one time in a investment mold ,
and by the way plaster of paris will cause a exploration of hot metal because you can't bake all of the water out of it .

I would appreciate those links very much I sorta skipped over sand molds because I thought the undercut on the track pad would be impossible to mold. I've looked into the lost wax and everyone says its an expensive process with all the equipment needed. I only thought about taking that route as a last resort if all other methods failed. We'll see if it ends up that way. As far as plaster of paris, I didn't know about the water issue. Is there any way around it? I was going to fire it in my kiln to dry it. I would think 1832 degrees Fahrenheit would be enough to dry it completely. I haven't found a lot of info on casting metal into ceramics and what Ive found. The info on the slurry mixture they used for plaster is always different or not very in depth.

[Jw.]

My first negative silicone mold attempt that I'll use to make a positive silicone. Them I'll use it to make my negative plaster mold. In the final third picture, the mold came out quite well except for a few bubbles around the bolts. This was a result from most likely not vacuum degassing the silicone before I poured. I would have except I have yet to make a vacuum chamber and get myself a pump. Those are on the list next.

[Jw.]

Second attempt was a failure again but I'm getting closer. Air bubbles all over and it cracked.



Third plaster mold attempt. Once again there were a few tiny bubbles in the silicone that can be seen as imperfections on the edge of the track pad.



Third time worked. Almost. Although it did not crack on me I still have a few air bubbles. Again I'm sure I can easily take care of those once I get my vacuum chamber built.