Stripped back wooden windows (bare wood now no paint) has a few black water stains along bottom by glass. Tried a wash, it took off a bit and lightened it but quite a few black stains remain.
Wood is old very dry, did repeat the wash quite a few times it seemed to soak it up, even tried light rubbing with scrub pad. Thought I’d try the paste so it would stay on longer, but.. Whatever I tried when mixing the oxalic acid I couldn’t make a consistency of paste
Read many web sites, mix oxalic crystals.. a few say powder, some say Oxalic acid comes as a crystalline powder. I got mine from reputable bee keeping site, it says 99.6 purity and is crystals.
After my attempts read some websites that said you can add talc or flour to make a paste but most of the others talk about the crystals making a paste. Mine looks like undisclosed sugar and I’m just wiping moist crystals across wood, or if I add more water crystals sink to bottom (totally saturated solution)
Am I expecting the paste like substance wrong and its more crysaline not smooth???
Replies
I've never done this myself. Beyond the paste, I think what you really want is to have the liquid oxalic acid solution on the wood longer before the liquid evaporates. How about applying a saturated oxalic solution onto the wood area of interest and then covering that region in saran wrap/cling wrap so that the water evaporates off much more slowly. Again, I've never done this but this would be my approach testing in an inconspicuous area first just in case.
Thanks bit difficult as just in front of glass cant wrap round, but yes think it needs to be on longer before evaporating. Did keep touching up before dried but not a lot of luck
I'll suggest something different. The oxalic acid residue will need to be neutralized before finishng or it could affect the adhesion.
I suggest going to a beauty supply store and picking up a pint of 50% hydrogen peroxide. Its a great oxidizer, but more important, breaks down into oxygen (which does the bleaching) and water - no residue to worry about once its dry.
I use it for a lot of purposes; it does not always work on wood, but it is cheap !