A hypothetical question on base pins/hollow base molds . . .

[bedbugbilly]

I have a number of hollow base molds for casting 58 caliber rifled-musket minie balls - Lyman, Ideal, Ohaus, etc. Of course these molds are steel blocks and come with steel base pins for forming the hollow base.

In the past, I have purchased some molds missing the base pins - and of course, at least in the Lyman molds, the diameter size of them vary depending upon the year they were made.

My question is this .. . . the base pins are made of steel. What, if any, problems might there be if a base pin was made out of aluminum and used in a steel block mold?

Might be a stupid question, I don't know? I'm thinking of any issues with the heat and possible expansion/contraction of an aluminum base pin when used with steel blocks?

My thoughts are that with aluminum rod of the correct diameter, a person could fairly easily turn a base pin, polish, etc. if you had a chuck large enough to chuck it in on a drill press. (at the present time, I don't have a metal lathe but am considering a small bench top lathe for doing small projects, etc.)

Anybody made or used an aluminum base pin in a set of steel blocks? Or, possibly brass?

At this point, just something that I thought of and am wondering about.

I have a number of NOE molds but none with base or nose pins - but I believe that Al's are all made from steel? So I'm thinking if the reverse were done (steel blocks with aluminum base pin - (I haven't measured mine as they vary but they would be in the .500 diameter range), it would work?

Your thoughts please. Thanks.

Jim

[dragon813gt]

NOE's RG molds use steel pins. Mihec uses steel parts for his cramer style brass molds. I don't see an issue w/ what you want to do.

[lightman]

I expect it would work. I also would bet that some of the members here that have lathes would make you a pin for a fair price. I would if I had a lathe.

[Bent Ramrod]

You might have trouble keeping the pointy end of the pin hot enough, and I would guess that you would find the other end (the one that has the wooden knob) getting plenty hot to pull out after casting.

Never tried a hollow base/point pin, but I've made thick aluminum sprue plates that worked great because they never overheated and smeared lead, no matter how fast I could cast. I've also used the aluminum version of the Lyman mould handles and those need gloved hands after things get up and running.

[country gent]

The difference in the expansion may be a issue as the aluminum will expand more and faster than the steel blocks. Another issue I see is wear removing and inserting the aluminum pins and twisting to lock them. They may wear faster and more than the steel ones. Lees hollow base moulds use aluminum pins inserts in aluminum blocks and they work well but here the expansion is close to the same and they aren't removed inserted and twisted to lock. I would try it especially if I have access to a lathe and can turn them myself.

[tucumcari_kid]

I agree, if you have the tools, it's worth a try. I think the aluminum pin would get stuck in the base if it expanded too much - should be a tight fit to begin with. Makes dropping the casts difficult. If it cools to where it can enter the mold, it may cool too fast to be effective. I have a brass wadcutter mold with a brass base pin. At least all the mold issues are constant with the same metals.

58 caliber might be big enough that those variables are less critical and it will hold the heat longer ... ???