Quote:
Originally Posted by GaryHLucas
I keep seeing mention of aluminum oxide being soft. what is the most popular abrasive used to make sandpaper? Aluminum Oxide, because it is extremely hard!.
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Gary, I think you have got yourself confused here. The form of Aluminum Oxide used for sandpaper is corundum which has relatively big crystals and is, as you say, extremely hard. It is made industrially from bauxite (the main ore of aluminum). The oxide coating which forms on the surface of aluminium is an amorphous form of the oxide and does not have the same properties as corundum. The coating is thin and relatively easily removed. For this reason, it is often made thicker for certain applications by anodising or hard anodising.
Stuart
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Leith (rhymes with teeth) is the port of the City of Edinburgh in Scotland. A Leither is someone who comes from that area.
I must go down to the sea again, to the lonely sea and the sky - I left my shoes and socks there, I wonder if they're dry?
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