Bleaching Timber

[echnidna]

What is the strongest safe bleach to use. ?

[astrid]

Hi Bob,

Dont think theres such a thing as a strong safe bleach.
depends on what you want to bleach and how white you want it.

Interesting point though.

sometimes we grab what we're used to without thinking about it.
lemon juice bleaches, as does wee and i suppose these are safe.
try lemon juice (or the other) and put it in the sun and see what happens.
women all over the world put their washing in the sun to bleach it.

as to the others in decending order, and i know someone will nit pick
Nappy san
household bleach(white king)
oxalic acid
peroxide
peroxide with amonia
lime
all of the above increase power in sunlight.

General warning to readers re safty applies

Astrid

[echnidna]

Thanks Astrid,
what I'm really wondering is,
can I bleach a very light coloured wood such as macrocarpra to snow white?

[astrid]

Dont know what timber that is,
Just experiment on offcut bits and see what happens.

Astrid

[dai sensei]

I've used household bleach and straight pool chlorine. Both work, but it did affect the outer fibres of the wood, not just the colour.

[specialist]

I once bleached some old red cedar with cloudy amonia. It took it from deep red to an orange brown colour, very nice. It seemed to go deeper than the top layer.

Robert

[journeyman Mick]

Bob,
you'll probably need to suck it and see. One thing though, oxalic acid tends to turn stuff a horrible yellow colour if applied too long or at too high a concentration.

Mick

[bitingmidge]

Bob, what are you trying to achieve?

If you are going to keep the timber raw and bleached, then use a normal chlorine bleach and a scrubbing brush after exposing it all to sunlight. This will chew out the outer fibres of the timber, as will any other bleach.

Remember how the old boiler stick used to wear away on your mum's washing "copper"?

If you are going to clear coat, there's a good reason to use a limewash or liming stain instead of a true bleach. In a real mix, there's a bit of bleach but not much, you paint it on, then wipe it off like a stain. That'll impart a bleached look, which can then be oiled or poly'd or whatever, and won't break down the timber.

Cheers,

P

[echnidna]

Just a furniture piece I've been thinking about for a while.
Bleaching and liming might be the go to get a snow white finish, though for a creamy white finish, bleach alone (or even nothing for a darker cream ) would do.

[Harry72]

What if you use one of those milk paints worked into the grain then wiped off, using a wood like tas oak if you sand it evenly with a coarse paper(say120~180g) with the grain it'll give the paint more area to bind into.

[astrid]

Bob, from all of these replies seems you can bleach the timber and wreck the grain, or keep the grain and compromise on the colour .I'd go for the grain,
If the timber is unusual in itself why spoil it by making it something it was never meant to be,
I have a philosophy with timber, that is you can tweak the tone but not change the colour without it resisting,
Ive changed ash to mahogany or pine to cedar at clients requests and it never looks quite rightIMHO.

Astrid

[echnidna]

I want to mix it up with some redgum and end up with a nice red and white piece.

[astrid]

Not having seen the timbers you are using, i think that the paler timber will look whiter contrasted against the redgum anyway.
The eye is always drawn to the darker timber,
If you try to make the pale timber paler, it might just draw the eye to it which is not what you want,
this is hard to explain,

Astrid