tom wrote:
Does this paddle have some special significance in your life? Yes, you
can use the oxalic acid you've had for 25 years. It'll work just fine.
But don't thank me, as I don't know the proportion to which you should
mix it down. Tom

Yes, it is a fine paddle - Clement of Quebec - ash spline and softwood
outside. It is amazing how many terrible canoe paddles are in use, and
how much better a good one is. I am embarrassed to say that I have
refinished it only one or two times.

To respond to others - I have used oxalic acid in the past to remove
black areas. But perhaps some other products are better.

Thanks for the help.