Black Rust Stains in Wood

Any old salts out there got a cure for reducing black rust stains in mahogany prior to varnishing, I tried bleach with little effect.

Try oxalic acid. I think you can still get this from a chemist. It's in fine crystal form, soluble in water. I don't remember the ratio but 3 to 1 by volume should work. Paint solution over bare affected surface, leave for a minute or so and then rinse with water. You may have to repeat. Go easy and try on a test patch first.

Many thanks Syd for the info.

Oxalic acid isn't very effective on mahogany. Try 'Rustins Two Part Wood Bleach' from any good (trade) paint supplier. Did the job for me.

Ian.