Bluing a Mold

[mto7464]

Has anyone tried Oxpho-blue on a mold. I got one in a trade that was covered in rust so I used Naval Jelly. Cleaned up really nice but is bare metal.

[missionary5155]

WEll that is an idea I have not tried... I just figured a mold would turn blue (oxidize) at it got hot.. and hotter...

[44man]

Yep, it will heat blue at casting temperatures. Oxpho blue will help if you are not going to use the mold for a while.

[docone31]

I have blued my iron molds. I blued the inside of one. It worked out ok, even the inside blueing. They smoked a bit getting them up to casting temp, but no biggee.

[leftiye]

I like to blue molds to create an oxide layer. The oxide layer is somewhat like "smoking" a mold, and makes it cast better (acts as an insulating layer, the mold casts cooler). Like others here have said molds do heat blue, that is part of "breaking in", or "seasoning" a mold.

[Lloyd Smale]

I had poor luck bluing the cavitys. It tended to create hot spots on the spot between the bullets that doesnt have much metal. it works great on the outside though.

[Boomer Mikey]

Oxpho cold blue will work great in providing some rust protection and if you burnish the oxide layer bullets will simply "fall" out of the mold.

Boomer :Fire:

[mto7464]

describe the "burnishing" procedure??

[anachronism]

I too, blue my moulds on occasion. Mikey might do it sifferently, but I burnish the moulds with a popsicle stick, or something similar. Just rub the desired area to a shine.

[longbow]

I have never bothered to blue a mould. I haven't had any rusty moulds I have cleaned up but I have lapped factory moulds, so removed the blue in the cavities and I have made several moulds. I just let them heat blue by getting them good and hot before casting.

Also, I always wipe a light coating of thin oil on my moulds while they are still quite warm after casting to make sure they don't rust ~ inside and out. Never had a problem and a quick wipe before casting takes the oil off.

Longbow

[quasi]

longbow, what kind of oil?

[longbow]

Usually just a light coat of gun oil, 3 in 1 oil or automatic transmission oil. Basically a light oil that coats well.

I often mix a bit of WD 40 with a light oil (about 50/50) but I don't use WD 40 on its own. I find mixed it thins the oil well and allows it to flow well.

Others say they have trouble casting if they oil their moulds but I just wipe off the oil and make sure the vent lines are clean before casting.

Different strokes.

I've generally lived in high humidity locations though so like to make sure my iron and steel is well coated with a rust protectant.

Longbow