centirfugal mold

[TonkaBass]

Has anyone made there own. Just looking for an end of winter project and to make some custom jigs for personal use.

[hydro]

Why? Just be sure your mold is preheated and you use alloy free lead (no tire weights). You should not need the centrifugal force to pour perfect castings.

[catfishkid]

why not tire weights? i use them to make sinkers for catfishing all the time. just curious

[TonkaBass]

because tire weights are alloyed lead, it freezes at a higher temprature. I want to use a centrifugal mold so I can make a wax model of a jig and them replace it with lead. I knew a guy who made one and used it to make jewlery. The amount of detail you get get is awesome. Also it would be a lot better than a machined mold and cheaper. I could play around with with the different designs I come up with until I find one I like, then I could get a mold made for that one.

[hydro]

So you want to try investment casting!

Check out jewlery supply resources and you should be able to find a setup. I think they work on a spring principle where you pour the metal and let it spin!

[TonkaBass]

Yep that's exactly how they work. I'll have to do some research for this one.

[ddsbyday]

Thats a pretty big operation to set up. I used to have one. My suggetion would be to wax your patterns and go to a dental lab and ask them to cast them for you. They will not use lead but a non precious alloy. If you want to do it yourself you will need the centrifuge, investement rings and bases. Investment,tongs and a torch. These can be found in jewelry and dental lab cataloges. You will see they are pricey. Another way to go is with silicone molds. You can pour those directly with lead. This is much faster and you can get as much detail as you want depending on your mold making abilities.

[hydro]

Why not try this: Since the initial pressure in the mold is a function of the specific gravity of the material times the sprue height, why not burn out the investment, fix a tall sprue pipe to the plaster and quickly pour the metal. You should get a hammer effect as the sprue fills up and pushes the molten metal into the mold cavity.

[TonkaBass]

so just use the weight of the lead to fill the cavity like on a normal mold, but make the sprue longer? I wonder if you would have to keep the sprue pipe hot the enitre time with a torch to keep the lead from freezing and clogging it. Sounds like a good idea though.

ddbyday- how do you make a silicone mold??? what kind of silicone do you use?

[ddsbyday]

Pure lead pours with as much detail as a centrifical lost wax investment casting. The investing and casting method is way too precise for a fishing lure cast with lead. As said before avoid the wheel weight lead. It is too hard and does not cast well. Investment(the material you encase your waxed jig) in is designed to compensate for the dimentional shrinkage or expansion of the object you are casting when it goes from a molten state to a solid. This ideally would produce an exact repica of your design. We are talking microns. I assure you this is not the way to go. U tube has some very good tutorials on mold making. The silicone is basically vulcanized rubber. Hilts molds is now taken over by another operation but you can get the silicone blanks which you vulcanize yourself. There is a really nice video on u Tube about centrifically casting vulcanized rubber molds for high production castings.

[TonkaBass]

Awesome info! Yeah like I'm sure you can tell, my eperience with these types of molds is limited. I have seen it done though, and remember it as being pretty simple, but I guess some things are easier said than done. Thanks for the information though, i appreciate it!