Metal Casting Zone

Mike I don't know if you will find these images helpful or not but seeing as how I have done about two dozen experiments the last few days trying to get the best textures in superfine scale I thought I would snap a couple fast shots and show you what I meant about lubricant and such.


The first shot is of a sample texture stamp and good old David. He has been hand polished with some "Wonder" Vigor rouge and a microfiber eyeglass polishing cloth. The texture stamp actually has a coat of polyurethane resin on that side for enameling experiments. But no polishing. Thats the palm of my hand for a rough scale.

The two Davids above had been poured and quickly placed into a pressure pot with zero lubricant or release agent. The top left only hand polished with a paper towel accross the flats with little effect. the upper right David is the "Wonder" polished from the first image.

The David in the lower left is a simple gravity pour with no lubricant. The David on the lower right is with brushing a coat of fine talc into the mold first and then blowing it out with a few gust from my mouth. Then simply gravity poured with no pressure added. Note that there is a slight dimpling from the talc or mica or graphite. I have a spray graphite on order and look forward to trying that for my gravity pours. And the rubber mold is made of Rebound-25 RTV silicon rubber. The metal is 281 from Rotometals. In all scenerios I am getting my best results from this metal. (58% bismuth + 42% tin)

Hope this helps.

OK third try for the second image.

Blobber

Mike I am sorry I got so far off the topic of lost-waxing crayon.

I just hate to see you loose your sculpts and then most likely the mold. With the Rebound-25 or similar press on or brush on rubber, you can mold the original without hurting it in the least. You mold one side, then put some Vaseline on the joining rubber surface and mold the other side. After it sets up, you just pull the mold off undercuts and all preserved. I could point you to some instructional DVDs that detail the process. And then you could cast many copies from the single rubber mold. Afterwards you have your original master and can even pour a crayon copy, microcrystaline wax copy, resin copy, or metal copy or all of the above from one single mold.

I dig the idea of recycling old pewter and the thriftiness of plaster. But of course you may be melting toxic lead and cadmium as well.

Different strokes for different folks. My dear Annie likes to suck on a burning weed day in and day out and I still can't grasp the virtue of it.

If you would like a sample of brush-on press on RTV big enough for one of your crayon sculpts PM me and I'll ship a sample to you mid next month at my actual cost, around $15, likely less. I won't get my next shipment until then.

Yep, I agree making ones own refreshment is cheaper and better. Mine averages about 80 cents a 2-liter. Cinnamon applesauce, vinegar and Splenda, sugar free latte syrups, theres no end to the variations. Regular soda really gets on my nerves anymore.

Blobber

Yeah Agreed about the toxins. I just bought a few lbs of pewter online.

Thanks for the offer. I plan to buy some mold compound eventually but I have some similar stuff now not for pewter but good enough for wax copies. I might eventually go for that sort of thing for pewter. My buddy makes copies with a paint on material I think it is the same thing. our plan for pewter is cuff links. not sure if we will use plaster or a silicon product for that.

Cool maybe you two can go halves on some materials.

Probably the same goo. "Rebound-25" and "Brush-On", are both made by Smooth-On and sold through various distributors; very common materials. I am all about fine detail and went the more expensive route with the platinum based silicones e.g. rebound, they last a lot longer once in production too. Sometimes two hundred castings of resin before loosing detail.

I just this evening ruined that particular mold with pewter from Rotometals that was not identified properly, but either way if it was their AC or R98 or whatever it melts at 440F and needs about 500F. Without graphite that fries the mold, makes it sticky. I forgot that. The graphite powder was sitting right there, duh! The pewters I have used so far almost always have a crazing or frosting fine texture. That is probably the cost of eliminating toxics from the formula.

The 281F needs no more than 340F and even this soft rubber handles it naked very well. I might do a plaster mold sometime just for kicks. A lot of sculptors still use it for backing up the silicone. I like Plasti-Paste (think fiberglass) or Magic-Sculpt (like J.B. Weld, but by the quart or gallon) for that. Both are light, and non-fragile. But nowheres as cheap as plaster.

For just a few sets of cuff-links; if you needed to do some polishing it would be no big deal. I can't really have any polishing as my objects are for rapid commercial production.

I was thinking if you made one side of the links in your chain sculpts thicker with a little finagling you might be able to cast it and then cut each link free, cutting away the overly thick side of each link.