Were Lyman Molds Blued Originally?

[Jkrem]

So I just bought a Lyman 357446 DC mold with pristine mold cavities that a previous owner in their infinite wisdom chose to polish the outside of, and remove most of the finish. I’m sure it will cast beautiful Boolits, but it got me thinking whether these were originally blued before shipping? Would smidgen of cold blue be out of line so I’m not blinded by the glare while casting?

265406
265407

[metricmonkeywrench]

I have a single cavity that had a bunch of rust all around, after a good cleaning in evaporust it took the surface back to “white” unfinished steel. Any bluing it may have had was long gone.

With repeated use the “color” is starting to return.

My new ones seemed to be blued.

[Mk42gunner]

It has been a while since I bought a brand new Lyman mold; but as I remember it was blue, but it seemed more like a heat blue oxide than a chemical blue.

I seem to recall that the mating faces weren't colored, which is why I think it was just heated with the mold faces together.

Hope this helps,

Robert

[gwpercle]

The older moulds seemed to have a surface that was darkened by heat and possibly oil , not so much a blued finish but a heat induced coloring ... it was like how you "blue" a repaired gun screw head by heating it up and quenching it in oil ... it's darkened but not a modern blue finish ...this may have been called heat blue or heat coloring.

It will not take but a few casting sessions before the bright surfaces will take on this darkening by the heat and oil .
Gary

[mattw]

gwpercle, that is what the finish on the older ones looks like to me. I am not sure, but looking at moulds, it appears to me that at some point they did start blueing them. I have used cold blue on a few that I really thought needed something.

[Outpost75]

Pre-heat the blocks on a hotplate, cast with the molds, and the patina will return on its own.

It does no harm to degrease and use Dichropan, but it isn't really necessary.

[GregLaROCHE]

I may be wrong, but I would never heat a mould and quench it in oil for fear of warping it.

[Jeff Michel]

I think Lyman molds were made out of 12L14 steel. The original "blue" was probably from stress relieving prior to machining. If you get your mold to casting temp enough times it will turn blue on it's own.

[jdfoxinc]

Lyman heat treats the mold blocks and blues the parts.

[square butte]

Pretty sure Lyman and Ideal molds are made of the Meehanite family of heat resisting cast or ductile irons.

[Jeff Michel]

I'll look into it and let everyone know what I find out. You can't heat treat iron or low carbon steel (12L14, 1018, etc.) since leaded steel (12L14) is cold finished, I suggested that the steel had been stress relieved (heat treated) prior to the cavities being cut to prevent the molds from warping after machining.

Update: On the MidwayUSA web sight:

Lyman 1-Cavity Bullet Molds are made from solid leaded-steel and machined to an exact and smooth super fine finish. The molds are then heat treated (that is why they are blue in color) and feature hardened steel alignment pins to provide many years of bullet casting service. Sprue plates are made from solid steel, ground flat and held tightly in place with tempered steel spring washers and screws. In addition, break-in is often half the time required for iron molds.

[Jkrem]

Well I guess these are tools, and it is more important how they work than how they look.

[square butte]

I stand corrected - My information came from a guy who had probably 400+ Lyman and Ideal molds on the shelf and had sold a good many more over the last 20 years.

[Rex]

Let us know how you like the bullet. Many really dislike that bullet but I've got a 2 holler and I get along with the bullet pretty good. Folks over on "The Art and Science of Casting Bullets" talk it up a lot.

[Jkrem]

Let us know how you like the bullet. Many really dislike that bullet but I've got a 2 holler and I get along with the bullet pretty good. Folks over on "The Art and Science of Casting Bullets" talk it up a lot.

I’m loading for a 38 SPL, I see in my old Lyman manual this is/was a popular 357 mag bullet. I bought the lot of three molds mainly to get the Lee 358150 hollow-point mold, and the 358432 wadcutter. I’ll try all three.

[BigEyeBob]

I may be wrong, but I would never heat a mould and quench it in oil for fear of warping it.

I agree ,too easy to warp the mould.Best way is to let it rust lightly on the exterior and card it to remove the rust with a carding brush and boil the mould in distilled water , place in hot oil after repeating the rusting process a few times until the desired colour is obtained .It goes without saying you should not rust the mating surfaces or the cavity.