Bob AZ wrote in rec.crafts.metalworking:

I am cleaning up the Water pot on my Baldor Grinder. The grinder and
the Water Pot had never been cleaned up at all in its 50 years of use.
I had to sandblast a lot of the grinder itself but the Water Pot is
aluminum and not as substantial as the grinder itself.

I have the outside of the Water Pot cleaned up nicely but the inside
seems to be leaching out, shall we say, some white powdery stuff that
easily wipes off but more come back in 24 hours or less.

Is there perhaps some acid or caustic liquid that will help? Or should
I simply wire brush until I get the inside down to the base metal
which I think is aluminum?

Thanks for the assistance.
Bob AZ

If your water supply is "rich" in Calcium [mine is] then try using some
vinegar to remove the buildup of Calcium resulting from the evaporation of
water in the pot.

I go through this periodically (about once a lustrum). grin