Replies

1. 
   Clay_Williamson | Aug 28, 1999 11:05pm | #1

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   Marcella.....oxalic acid is probably the best all around wood bleach..but its extremely dangerous, a pretty potent poison. There are other methods. Start with your stripper. KS - 3 from Klean strip is a pretty good meth/chloride stripper; it's water soluble so clean-up is safe, I like to use automotive thinners to remove the residue and clean the wood after stripping, (Dupont 3602-s) Once your down to your clean bear wood, try sanding out any of the stains/220 grit up to a 400 grit.

   If the stains are still evident then try lime juice, it's an acid also. If no luck try chlorox, it's a good bleach, dilute it to your needs and do some test patterns in small areas first.

   If no luck then go to your oxalic, remember to dilute it 75% w/ water 1st and try test patterns first. Increase the strength as needed to acheive the effect desired.

   A couple of hints :
   Once your bleach/acid has worked dilute the mixture you have used 100% and then wash the entire top to blend your chemical evenly.

   After that wash the entire surface w/ water and then sand w/ 220 and go up to a 500 grit.

   Vacume your surface, wash it with your auto thinner and rotate your rags until nothing shows on your rags.....you should now be ready to stain/seal and finish.

1. 
   Michael_Richwine | Aug 29, 1999 03:51am | #2

   *Here's a slightly different take on Oxalic acid.I refinish / repair / restore a lot of furniture, and Oxalic acid is the first thing I reach for to take out black water stains and weathering. I use other methods too but oxalic takes care of 75% of what I run into.I mix about 3/4 pound of crystals to a gallon of HOT water (3 oz to a quart), and apply it hot -- it works faster. Once the stain is gone, it is usually good to spread the solution around over the surface to prevent spotting or uneven bleaching.Regarding toxicity. You do have to be careful with it, but the primary danger is from the crystals formed when it dries. They are very sharp, and can cause bleeding of lungs and mucous tissues.So, with that in mind, rinse thoroughly with several changes of water. Then let dry thoroughly, and rub with a dark cloth. If there is any residue, rinse again and let dry, until no white residue shows. Then sand and finish normally. By all means, don't sand as long as there is any oxalic residue left -- your nose and throat will tell you that you made a mistake.Michael R.