As part of trying to repair the damage caused by the Ex, I have been trying to get some deep black water stains out of some solid oak windowsills.
Removing all the coating - sanding back to bare wood - and serious loading of thick bleach seems to be doing the trick.
Some dripped onto some emulsion, and to my surprsie lifted it straight off the plaster!
No big deal since its all being filled sanded and redecked anyway, but I never knew bleach would strip emulsion.
A little surprising maybe, but perhaps not on closer examination.
It seems the minimum pH of bleach is 11. Some sources give the maximum as high as 13, which would make it very alkaline indeed, and quite capable of removing paint given enough time.
It was pretty much instant.
Waitrose Essential Thick Household Bleach. I think..:-)
On 19:01 17 Oct 2018, Jeff Layman wrote in news:pq7tcs$kuc$ snipped-for-privacy@dont-email.me:
Wouldn't strong household bleach weaken the structure of wood by damaging lignin?
Eventually, yes. See Table 1 here for an interesting comparison of the effect of 32 days of 10% NaOH (or HCl) on various types of wood.
Note the difference between conifers and hardwoods. The former are more resistant - hence the use of hot caustic baths to make stripped pine. These are, to say the least, unsuitable for painted hardwoods such as oak.
For removing stains from wood, oxalic acid dissolved in warm water is the usual treatment. Apply, scrub, leave for a bit, then rinse well. Repeat if necessary.
I am not so sure. Bleach is a very mild alakli. Compared with caustic.
Its not the first time I have bleached oak.
It doesnt penetrate very far and once the stains are gone you just wash it clean and then re-stain it.
Needless to say it will be washed later today to remove any excess bleach.
I will post some images whan I get a round tuit.
That seems to be specific for IRON stains.
Not water stains.
Its commonly used on water stains as well.
e.g.
On 11:52 18 Oct 2018, The Natural Philosopher wrote in news:pq9okl$cmh$ snipped-for-privacy@dont-email.me:
Have a look at this article and decide for yourself.
Ok. Ta. Filed for future reference
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