watermark

[Guest]

In my boat there is a black watermark on wood panel, could anyone suggest how I might get rid of it without marking the wood.

 

[longjohnsilver]

Try oxalic acid, if on a vertical surface mix it with wall paper paste to keep it in place. You can buy the oxalic acid cheaply from chemists, but be careful, it is very poisonous!

 

[Guest]

I purchased Oxalyc acid powder from my local chemist to remove stains from the gel-coat. Anyone know what the proportions are for mixing with water?

 

[longjohnsilver]

From memory you don't use too much water as I think you keep adding the oxalic acid until it will not disolve any further.