Metal Casting Zone

My uncle wants me to cast him an enblem for his car, and im not sure yet how to go about making the mold. Its flat, 3/16 thick and only 1 1/2x1 1/2inches and has two post that are threaded. He doesn't know what metal he wants to cast it in yet, but ill probley try zinc first. Im thinking about makeing the mold with the treads cast into it i have never tried it so not really sure if it will turn out. Im also wondering how well different metals will cast that thin. Im going to try it in zinc, aluminium, brass, and bronze. Any advice would be great

well this is simple! firstly you will need a flask like i use. zinc would be best so you can have it plated. i think i could do it. in sand! wax tho might be better if you can make a wax mold (lost wax) so the surface would come out smoother. if the emblem was originally die cast you might not be able to duplicate it to perfection but you might be able to polish it up with a dremel or die grinder to satifaction.

Sand should work just fine, just use the finest sand you can get to do it. Play sand won't cut it without a lot of grinding,sanding and polishing after. As far as the metal, I betcha that if the originals are metal, they are made out of ZA12 or something similar, it's a zinc/aluminum alloy (pot metal). A good source for the replacements would also be metal auto trim pieces, they are probably ZA12 as well. Pours and flows nicely, so a relatively thin piece like that should be no problem. A far as the threads, you should be able to cast them in place and have them come out pretty good. The trick is going to be getting the bolt or threaded rod to locate correctly in the mold.

Thanks for the information, I checked budget casting suply and all they had was za-27 at $5.10 a pound any idea how well this alloy will do.

Should work just fine, although BCS has high prices on stuff. I'd just go to a local junkyard or autobody shop and tell them you are looking for metal auto trim pieces. They probably have quite a bit of broken stuff that is not repairable that they would let you buy or have for a lot cheaper. You will have to re-melt it and get the chrome plating off it but that is minor.

Hello, Newbie here.
The parts shown are for a 1929/31 windshield regulator. The shaft with the arrow pointing to it, gets a worm gear cast on it. I reproduce all 6 gears and the housing.

I use rubber spincast molds for all sorts of auto and marine nameplates.
The equipment in expensive for the home caster, but a simple, single cavity mold for a
nameplate will run $100.00 or less, nameplate will cost $10.00.

To try it at home, the suggestion of used moldings, from old cars, is good. Just melt them down, clean off the dross (plating etc)that floats to the surface and check the temp at around 750 degrees F.

I also use Petro Bond sand type casting, if the part isn't too detailed (small openings).
I usually cast posts or studs on the back and then run a thread die over them after they are cast.
Good Zinc alloy can be bought cheaper than $4.00 per lb. I usually use a part of new with old parts remelted. It gives a better finish for plating.

The rubber molds will give the parts some shrink. Investment casting will give the most shrink and petro bond, the least.

Does anybody know where I can buy zinc alloy ingots in the US, so far all I can find is places that want to sell buy the ton, except for budget casting supply. I only need ten or so pounds to get started to test.

83 and newer pennies, melt em !!!! good clean zinc

I think it actually illegal to melt down pennies.
The metal would also have the copper plating in it, some that would mix in and affect the melt.
McMaster-Carr and Contenti have small amounts of zinc. Single small bars are not as cheap per lb as a larger amount, but it would get you started. Use the alloy with the least amount of aluminum for starters.

I use a lot of ZA 2 as it plates well and has good strength. The 2 means 2% aluminum.

What is the nameplate that you want to make?

ZA-27 has way too much aluminum for casting small parts.
ZA- 2 is normally used for emblems and toys.