what are galls

Answered with respect to metal, in a reply to your multi-question post. Also with respect to gall ink, a form of iron compound. (Gall ink can be removed by the use of oxalic acid, by the way. Just in case you ever get any on your best Sunday-go-to-meeting shirt.)

Also, if you are talking about horses, a gall is a sore spot or granulating wound on the hide, usually on the withers, from a poorly-fitting harness strap or saddle. Not a nice thing at all, eh?

Plant galls are sort of cyst-like tumors caused by insects, often wasps, laying eggs in them.

Plain old gall is an archaic term for stomach bile, excreted from the gall bladder, located on the common bile duct. Not a problem to me, as I no longer have a gall bladder. You didn't need to know that, did you? (grin)

Another form of gall is a disimilar metal surface deformation caused by a poor fit or improper combination of materials. It actually is very close to definition number two by Mr. Waugh, but in a different application. Some materials by their nature can gall on themselves. Certain alloys of aluminum are bad about it in their unfinished state. Consider that freshly exposed aluminum in almost every series below 6000 can gall on itself very easily due to immediate oxidation when exposed to air.

If this is too galling, just pass on it. ;-)

Ironscot,

I went through the explanation of metal galling in another response, but I'm sorry I didn't hink to include your aluminum example. That is one of the clearest examples most metal workers will likely see. Good one!

Thanks Mr. Waugh. Just goes to show that even a blind hog can find an acorn every now and again. LOL Have a goodun!

See the discussion on Cold Shuts in this section, Dodge gives a good description of what I know as a Gall in the first part of his answer on cold shuts. Also you can see my reply there for further info.

Cheers, Bruce