Metal Casting Zone

How do i cast hundereds of the same item at home,do i use sand or should i be using a pernament mould and how do i do this.Can anyone give me any good advice on this subject.

Lets start by asking, What are you going to cast? How big? What material?

Hi,i am wanting to cast chain links for a radio controlled bulldozer.They are pretty much the same as a standard link except a lot more bullky and around 50mm long 40 mm wide and around 30mm depth.Then there are the shoes to bolt on top of the chain links.I have attached a picture of the links for you to look at.

Sorry forgot to mention its aluminium i was using basically because its light and it works well on the 1/6th and 1/4 scale tanks. Thanks.

Looking at the part, it looks like there is a left and right side with a pipe connecting the two. Are they made out of aluminum now?
if you have a few of them you can take apart I would line them up in a couple of lines
connect them with runners and sand cast.
the other choice is to make a silicone mold off them and make wax patterens for investment casting that you can sprue up on a tree.

Hi Andy 01
Can see why you need a large number of these for tank tracks. As a military modeler from years back I have a good idea what you are putting together . I didn't work in such a big scale. These are not unlike the size of some of the belt buckels that I was casting by the spin casting tec a few years ago. These buckels were cast in Zinc/Aluminium or EZDA 5 It may be known as a different alloy where you are. EZDA was short for ELECTOLIDIC DIE CASTING ALLOY The silicone mould was made of the master by vaulcanizing a spin mould of the original ,and hundreds of spin castings can be made from this mould ,though the high temps of the Zinc /AL alloy 420oC plus ,deteriorates the rubber mould quickly. The buckels were of good detail and light and strong but the alloy was very brittle. Sand casting would be ok for these but the spin casting would give much better repoduction of detail. Needing less clean up. Hope this helps you Andy Johncast Australia

Hi,thanks for replying.The problem i have is i dont even have a link to copy from yet so i will have to make one to use as a mould.I have decided to go down the line of sand casting mainly because i have watched numerous vids on you tube and have become quiet farmilier with the proccess.Before i forget when casting aluminium do i need to put degasing tablets in during the melt or at the end and is there an alternative,because theres a guy on youtube throwing salt and bycarbonate or somthing of that description into the melt.Anyway thanks for your sugestions i really do appreciate it.Heres another picture which shows the assemblly in more detail. Thanks again.

That looks like a fun project.
De-gassing of Aluminium can be done with the dry pool clorine cystals. Here I buy Pool Shock and put about a teaspoonfull on top and push it down with my stirring spoon. I've only done it a couple times and you really have to watch the gas that comes off. Don't breathe it.
If you have fairly clean scrap or melt the metal down a couple times, then you may only need to give it a good stir and let it set for a bit before you pour.
If you have a lot of slag you can use Lite Salt as a flux and recover some of the Al from the slag. I melted a box of salt in the furnace in a stainless steel bowl, let it set to cool and it broke up into cubes about the size of a sugar cube. Again, I don't melt cans or much dirty thin scrap so I don't use this much either. Using clean scrap or melting it down into ingots first will help the Al so you won't have much gas or slag.

Hi thanks for the reply.If i have bought aluminium and not scrap do i still need to deegas the melt,and will i still need flux.What exactlly is the purpose of flux.I know degasing chases the hydrogen out but what does the flux do,do i need both. Thanks Andy.

If you buy Al alloy ingots I don't think you would need either. You could ask the company you get it from what they recommend. But, if they sell it they will probably recommend it.