Brass-colored Lyman mould

[LeadHead72]

Recently I picked up this never-used Lyman round-ball mould that is unlike any other I've ever seen. It looks like brass but responds to a magnet. Tonight I took it apart and thoroughly cleaned it for safe storage. The picture below was taken after the cleaning, so the color is definitely not any type of residue and it's also the same color inside the threaded hole for the sprue plate screw.
A person who many consider to be an expert in bullet casting said that the Meehanite which Lyman uses can be a yellowish color after the machining process and before the bluing process. He wonders if perhaps someone forgot to put it through the bluing process before shipping it.
Your thoughts? I find it very interesting and unique.

[380AUTO]

That thing is awesome. Never seen a Lyman like that.

[M-Tecs]

Rust remover will take bluing off????

[Winger Ed.]

It's doubtful it left the factory like that.

There's a few common cleaner type chemicals out there that will strip off bluing on contact.
Somebody probably 'cleaned' it with one.

[LeadHead72]

It's doubtful it left the factory like that.

There's a few common cleaner type chemicals out there that will strip off bluing on contact.
Somebody probably 'cleaned' it with one.

On quite a few occasions I've chemically stripped rust/bluing from Lyman moulds and have never had them turn brass-colored, but rather the typical "in the white" steel color.

[country gent]

Im wondering if it could be a darker straw color from heat. Steel will go straw to purples/greens to blues to black with different heat ranges.

[LeadHead72]

Im wondering if it could be a darker straw color from heat. Steel will go straw to purples/greens to blues to black with different heat ranges.

This was sold to me as a new mould and from all other appearances it seems to be unused. Of course it's not impossible that it could have been heat-cycled.

[country gent]

May be a new unused mould. The yellow may have come from a anneal cycle and it missed being blued. Heating the blocks to lightly anneal makes them easier to machine with out warpage and increases tool life.

[challenger_i]

Yellow zinc, or cad-plated for corrosion control? Perhaps a query to Lyman might shed some light on the matter?

[jdgabbard]

I have a few molds from Ideal that have patches that look similar. It's definitely still iron. Not brass.

[Rattlesnake Charlie]

Well, how does it cast in its current condition? If it ain't broke, don't fix it.

[ACC]

Looks to me that someone scrubbed the bluing off.

ACC

[Recycled bullet]

Gorgeous it looks like brass

[1eyedjack]

I have an ribs 9 115 rn machine mold I bought on fleabay for cheap. It is well used but usable after some modifications to convert it into hand casting mold. It also has some kind of brass or yellow tint to it but is some kind of steel or steel alloy. Still casting a good bullet but has definitely seen substantial use.

[Bazoo]

I'm definitely interested in what is going on with it, thanks for sharing.

[longbow]

If it is magnetic it definitely isn't brass.

I don't think Lyman blues moulds in a bluing tank, I believe they heat blue. As mentioned above as the iron goes through the temperature ranges the surface coulour will change from a pale straw through to blue. That heat bluing would be done after all machining so yes, insode threaded or dilled/reamed holes would also be the same colour.

I make moulds from mild steel and they heat blue in use. They start off shiny steel in as machined condition but change colour in use:



It depends on what temperature the metal is taken to as to what colour it turns.

I suspect that your mould was heated to below usual temperature when it was heat blued/baked. It may well darken up with use.

Longbow

[Recycled bullet]

I wonder what amazing colors it will become if you get it hot and wipe it with an oily rag.

[1Hawkeye]

I've seen blued metal turn that color after being scrubbed with a brass brush. Could this be the case.

[LeadHead72]

I've seen blued metal turn that color after being scrubbed with a brass brush. Could this be the case.

Don't think so. Even though it's never been used I thoroughly cleaned it myself after receiving it. And as noted previously, the color is consistent even down into the threaded hole for the sprue-plate screw.

[20:1]

I've see this from time to time on other moulds. I believe it'll turn blue when you first use it. I often clean up used moulds I've purchased with Evaporust, then scrub them after a long soak and oil. They turn blue with the first use. It could be that this is an unused factory mould that got its final cleaning and oiling but didn't get heated to blue it. Hensley & Gibbs moulds had a similar finish as well.