18 of 19 people found the following review helpful
This review is from: Liberon WB500 500ml Wood Bleacher (DIY & Tools)
We had a few black marks on our oak kitchen worktop. There were some small ones which we could live with, but then our Le Creuset casserole was left out on the slightly wet worktop, and a large casserole-shaped black mark appeared that we couldn't ignore. Having researched the interweb, I came to the conclusion that "wood bleach" or oxalic acid was what was required. The black mark is formed from oxidisation (essentially rust) accelerated by the tannin in the oak.
I ordered some wood bleacher, and yesterday used a modelling brush to sparingly apply a few drops to the marks. The stains disappeared almost immediately! As instructed, I then washed off the bleach and lightly sanded the surface before re-oiling. The only problem I have now is that the earlier failed attempts to remove the marks had removed a lot of the oil, so I'm having trouble getting the original finish back! I think that if I had used the wood bleach as soon as the stain had appeared, I wouldn't have this problem.