? re: mokume gane

[bjmac]

Ed, some time ago (in a land far away!) you told me that once i use my forge for making mokume, that I could not use it for Damascus. Does that include heat treat after shaping ? and what is the reason for the removal of Damascus? and are any other prohibitions other than damascus? thanks, Bruce

[KenH]

I'll be VERY interested in Ed's reply - I can't imagine why making mokume would have any affect (effect?) on Damascus.

[Ed Caffrey]

NO! Not "USE" the forge for making mokume.... but IF you happen to MELT any non-ferrous material IN your forge while making mokume. (Mokume is always non-ferrous materials) Also, the size of the problem/fix is relative to the amount/size of non-ferrous that melted.

The biggest offender is copper, but most any non-ferrous will produce a gas when it melts, that permeates the entire forge lining, and in the case of ceramic fiber blanket, the only way to remove it is to TOTALLY tear out the lining and redo it.

Castable lining is a bit easier... wire brush the spot(s) where a drop/drip landed until you take out about 1/8" deep, then patch it with kiln cement or whatever castable.

In coal forges with cast iron firepots, it requires grinding away the surface of the cast iron in the spot/area that the material melted/stuck to..... and in some cases, if the amount of non-ferrous material is large, discarding that firepot, because the melted material gets into the cast iron pores and by the time it's ground out, the firepot wall is too thin.

I've experienced all three scenarios, two of them when I too new/ignorant to know what I was doing was a bad thing, and the third when I was hosting a Hammer-In, and some knucklehead threw .22 casings into my welding forge (which is why Ed has hosted exactly ONE Hammer-In, and no more)

[bjmac]

Thanks for the reply, Ed. So, to make certain that I understand , I only have to redo my forge if I melt and spill mokume in the forge. There is no problem with the making of mokume, right?

[Ed Caffrey]

Originally Posted by bjmac

Thanks for the reply, Ed. So, to make certain that I understand , I only have to redo my forge if I melt and spill mokume in the forge. There is no problem with the making of mokume, right?

Yes.... that is correct.

This is a situation where having an ACCURATE pyrometer installed in your forge, AND knowing the lowest melting point of the materials you're using for mokume, can save you a ton of heartache, work, and money.

[bjmac]

very , very good to know. thanks

[KenH]

As I said in my post I never even considered making mokume in the forge. Since the issue seems to be the copper, or other non-ferrous metals releasing a gas that ruins the ceramic blade or other insulation.

Just how does it "ruin" the insulation? Is it because the copper gas gets in the insulation and ruins the insulation property of the insulation so it doesn't do a good job of insulation?

Based on this I suspect it's not a good idea at all to use the forge for melting copper or brass to cast up a fitting either. I have been thinking about trying that, but won't be doing that now. Thanks Ed.

Ken H>