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To answer the question of what is potash, it is a type of salt. Table salt is Sodium Chloride; potash is Potassium Chloride. It is typically found in the same places as normal salt. It is usually a crystal or powder, just like table salt. Incidentally, the reason that potash is usually a reddish color is due to iron traces in the deposits. Potash is mainly used in fertilizer production.
Couplers are usually rusty because by law you are not allowed to paint a coupler. Paint could conceivably hide a crack, so it is not permitted. Raw steel castings get a thin layer of surface rust very quickly, so even when the cars are being built, the couplers are rusty.
richarddschivley Member # 274
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cnotp: Let me try and help answer your questions.... #1: Potash, I beieve is, potassium hydroxide, it is a chemical, a white caustis solid, KOH, used in making soft soap. #2: I believe the reason couplers always seem to look rusty is that the only part that makes any contact is the closing-grip area, where the couplers join together. The other exterior parts never receive any real wear, and the un-machined areas simply rust do to the iron ore in it's make up. #3: I'm not completely sure on this one, but some steels, such as "stainless", won't rust in wet weather. Some other rolls of steel have a fairly good coating of oils, on them while being manufactured. Other rolls of materials, such as aluminum, also will not rust, as I'm sure you already know. I hope I've been some help to you. Richard
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