Discolouration across the grain

[marcus]

OK, I've just been sanding some oak which revealed on several pieces dark discoloration which runs across the grain with a clearly defined, slightly darker edge:

It goes deep - I planed as much as I dared without affecting it at all....

Any ideas how it got there, and if there's any way to remove or at least disguise it somewhat - oxalic acid?

I really don't want to have to bin these pieces - the timber all comes from one tree and is perfectly matched - and I don't have any more

Cheers

Marcus

 

[dickm]

If it weren't such a straight line, I'd suggest that it was an effect of damp getting in to the end grain. Other thought - was the darker bit exposed in some way that the rest was not? If it was, in somewhere with ammonia around (stable?) it could be a sort of fuming?

 

[wizer]

Looks like the end has been dipped in water ? Isn't it Oxalic Acid in these cases?

Can't you work around it?

 

[marcus]

My first thought was that it had been in water at some point, although I'd be a little surprised as it came from a reputable supplier, and has been indoors ever since. Now that the initial panic has worn off I've found an off-cut with the same stain so will give oxalic a go on that....

Marcus

 

[Chris Knight]

I think it's sticker stain from the sticks separating boards during the drying process. You could indeed try bleaching it with oxalic acid.

 

[Ironballs]

I'd go along with Chris, water stain from drying or stickering. Maple is very prone to this and the stains can go very deep, you either live with it as a feature or get a new piece of wood

 

[newt]

I have had this on Oak, and as you sat goes a long way inside. Mine however was much wider than a typical stick.

 

[Chris Knight]

I suspect the staining can migrate preferentially along the grain a little like spalting does. Having said that, I wonder how the tyloses in oak affect that?