my first try at a rubber mold

[Rasper]

You at least have to get the free water out of the plaster. You could do that in the kitchen oven at 500 degrees for a few hours.

I make my plaster about the consistency of ordinary gravy, not the thick stuff. That accomplishes two things. First, you want it to be able to run into every little crack and cranny on your wax. Second, when that water evaporates, the plaster is more porous, allowing gas to escape through the mold when you pour.

Richard

[dallen]

I baked what I screwed up yesterday in the oven for several hours and hope if it warms up some outside today to pour it, other wise its going to be a couple days before I can try the things that you have mentioned like mixing in sand in the mix to toughen it up.
finally figured out what was written on the bag for a product name, the stuff I have is UltraCal 30. Someone did a really bad stamp job.

DA

[dallen]

OK it was warm today like in the high 60's instead of like yesterday when the wind chill was below freezing, wish it would make up its damn mind and either warm up or get cold and stay cold.

enough of that crap for now, I got out and fired up the furnaces, and used one to heat the mold up to pretty warm didn't take its temp. and used the little one to melt more then enough aluminum to fill the mold with.

BUT, as we all know it very seldom goes right on the first try, metal ran out the bottom of the mold, mold had cracks all over it before I poured in the metal. and I think that the dark colored investment is from not all of the wax being burned out.

I know that I messed up by doing the burn out as soon as I did, but I also already knew that the mold wasn't going to be any good because of some problems during the investment stage.

I figure that to do this right I need to setup the kiln and program the controller to do the burn out in stages, and also I need to get up around a 1000 degrees even for aluminum, this mold had smoke or steam coming out of the sprue hole when I pulled it out to pour.

Right the ugly photos

[Rasper]

You're right. You have to get the moisture and the wax residue burnt out.

That grip looks good though. The checkered part that turned out.

Richard

[dallen]

its a learning experience which one of the reasons I'm doing this. plus its a way of copying parts with excellent detail. One of the things I need is to figure out how to do the investing so that I have as small a package as possible to burnout. No sense in having a great big chunk to have to dry out when a small one will do.

anyway its back to the molding bench to get another one ready to burnout and see if I can get a good pour.

DA

[mite5255]

abstract
sculpted casting

[dallen]

I guess I could mount it by the spure onto a polished board and stick a little blue led under it then list it on Evil Bay for an outrageous amount of CASH, saying thats its and original and that there will never be another one like it.

Then again I could just throw it back in the pot next time I melt to seee what else is hiding inside of it.

worked on the pump system I'm trying to get set up today.
DA

[dallen]

no playing outside today with the foundry stuff, got white stuff blowing around in the yard and it isn't fog.

Damn but I wish this winter was over, freaking up and down in the temp one day its 70 next day it'll freeze the balls off a witch.

DA

[dallen]

shop monster says F$%k a bunch of cold weather

DA