oak turning black/blue?

[Mick Dempsey]

Plus The purpling is patchy, not large areas like this.

[agrimog]

that end has been wet, when you cut and exposed the fresh timber,the moisture has carried enough off the metal of the chain to cause tannin staining......oak + moisture + steel = blue/black tannin stains. I've even had it when milling out and a light shower passes through, speckles all over fresh milled timber

[Gary24]

Maybe a dog cocked his leg on it last night:lol:

[pete23]

Oxalic acid ( think that's correct) is good for getting these small stains out of oak, not a chance on that though.

[dirtybiker]

Oxalic acid ( think that's correct) is good for getting these small stains out of oak, not a chance on that though.

 

Oxalic acid will get that stain out.

It looks like sugar, dissolve it in hot water and paint it on whilst still hot (ish) repeat 2 or 3 times and give it a scrub with the paint brush in between coats. Then rinse it off or jet wash it.

It will go a light straw colour and continue to lighten over the next 24 hours as the wood drys.

Then give it a coat of wax (fiddes).

This will work, did my whole oak framed house like this.

[pete23]

I stand corrected

[agg221]

Did you drag it over the truck bed or anything else steel? If so, that's probably where a lot of the staining was picked up. A light sanding and it will disappear (if you don't go for the oxalic route).

 

Alec

[Rough Hewn]

Oxidisation of exposed ferrous material probably.

The speed depends on moisture content and tannins.

Probably

[delabodge]

Did you drag it over the truck bed or anything else steel? If so, that's probably where a lot of the staining was picked up. A light sanding and it will disappear (if you don't go for the oxalic route).

 

Alec

 

I was thinking this:thumbup:

[flatyre]

Ah I figured it out! The wood didn't change colour until yesterday/day before, a week after cutting it. But I'm trying to clean the place up for Christmas and took the angle grinder to the old load bed off the L200, white thing in the background. It was right in front of the beam, so must have got showered in sparks. Thanks for solving the mystery folks:thumbup1: Quite amazing that a combination of iron filings and the natural tannins can create such a reaction, and is it just iron or do other metals?