What's the difference in an aluminum rb mold and a steel mold.

[Lippy984]

I only have experience with aluminum. I don’t usually have time on my hands to cast, but when I do, sometimes it may be 20deg or below freezing temperatures. I think this is why I have a hard time keeping my mould a consistent temperature. Last few times I’ve been tossing half back in the pot. I need to try it above freezing to prove that out, because the inconsistency is kinda counterproductive when I’m strapped for time.

 

[Clavina]

In time the top opening of an aluminium ball mould will get elongated by repeated use of the sprue cut off. I'm quite happy to buy these (mainly .440 and smaller) in the UK for conversion to Monkey Tail moulds.

 

[Josephg]

Lube

Lube? What kind of lube? It would go between the top of the mold and the sprue plate?

 

[Woody Morgan]

I keep a smooth file and a stainless brush handy to "dress" the underside of the sprueplate.
Does pretty good in avoiding galling aluminum molds.

 

[Josephg]

When I get a new mold now the sprue plate gets surface ground and the blocks checked for burrs. The gauling I experience was with Lee molds and one NOE mold. The sprue plates had burrs on the edges. For lube I use soapstone on all my molds. Anything else winds up in the cavity which always spoils the casting. May be a lube I'm not aware of? Graphite?

 

[mooman76]

You need a lube that works well in high temp so it doesn't burn and build up. 2cycle oil works well and there are others. Use very sparingly, in fact I apply with a Qtip. You don't want it in the cavities, it causes pour fill out. Use on all moving parts and I put a thin layer on the under side of the sprue plate to prevent galling.

 

[GREENSWLDE]

We used to buy a product called ZEBO. or ZEBRITE Came in a tube and was made for Blacking Cast Iron grates and cooking ranges. Very easy to use and economical. Possibly called Grate Black today . Rub it on with cloth. One coating last for ages. Mostly Graphite. OLD DOG.

 

[GREENSWLDE]

GRATE BLACK>> Just looked it up on the Net. Sold at Amazon under the name DIRT BUSTER.Stove Polish.. OLD DOG..

 

[toot]

the metal, aluminum VRS iron. that is the difference. and the heating properties of the two as stated.

 

[Rock Home Isle]

Aluminum is cheaper. I'm sure there must be a reason.

I've used both.

Years ago I quit using the steel molds because it took so long to get the mold hot enough to start producing good quality balls.

The aluminum molds are apparently cheaper to make and cast very accurate projectiles, just as the steel will molds do, but the aluminum molds heat up quicker and cool down quicker...so yeah I've switched over completely to aluminum...unless its a projectile that is no longer made and all I have is steel. Then yeah, I'll bite the bullet and use steel.

 

[Scota@4570]

Lube? What kind of lube? It would go between the top of the mold and the sprue plate?

I use moly paste. IT is no good for conditioning the bore of a modern rifle. IT is great for this. Oil will seep into the cavity and ruin the cast balls. High temp moly wheel bearing grease works too. I put a dab of paste on a q-tip and rub it on the underside of the plate. IF the plate pivot screw come out easily, it not staked, take the plate off. Polish with 600 paper backed on a flat surface. Knock off the edges that might dig into the blocks. Treat the underside of the plate with the moly paste and re install it. Use only the absolute minimum amount of lube. The plate should swing nice and smooth. If it is dragging stop and deal with it.

 

[amcmullen]

Only problem I ever had with aluminum molds is gauling of the blocks by the sprue plate. Just annoying, not a huge problem.

When you say gauling, are you talking about the hole in the top of the aluminum mold? If so, mine did the same thing. It opened up the top of the round all mold. Aluminum is way too thin up top for a soft metal. I don't think any lube would have helped since it would directly effect the pour.

Doesn't seem to effect accuracy, at least not noticeable to me.

 

[billraby]

I have a mold for 4 bore balls that is made of brass. It works great.

 

[Eric Krewson]

I have bag molds (that I never used) steel molds, Lee molds and a Tanner mold, all do what they are supposed to do. I haven't bought anything but Lee molds in years, I know their quality has gone way up in recent years because I have several very old ones that are questionable in their fit and finish.