Curious Wood staining, assume drying stains.

[CHJ]

Runs through the length of the piece.

Carcase timber off-cut from Furniture manufacturer.

 

[n0legs]

Could it be from a fireproofing treatment as it's from the furniture industry?

 

[chipmunk]

Hi Chas,
I have had that very same staining when trying to dry holly spindle squares - nice and white on the outside but when cut open there's a nasty grey middle that's revealed. I'm sure you can imagine how depressing it is.

I think it's because the outside dries before the sugars start to break down but internally there's sufficient moisture for spalting to begin/continue.
Jon

 

[CHJ]

Thankfully this is something I won't be using for anything serious, just used as temporary support hot melt chucks etc.
I can now see where some of the stuff I've inherited in the past that had been machined got the dark colour streaks from.

I've yet to get to the Holly I've got stored/drying, not very optimistic that it will be usable in its natural colour state.

 

[Sgian Dubh]

The cause, I suspect, is as described by Gard* et al (2010, p7) who discusses this effect in pale timbers, such as maple: it is “enzymatic oxidation of accessory phenolic compounds” especially in the case of thicker boards, and is the result of too slow drying of freshly milled boards. Immediate end rearing of freshly milled sycamore is one technique to alleviate the problem prior to seasoning, either air drying or kiln drying. If the converted wood is to be kiln dried the generally accepted practice is to immediately sticker up the planks, get the stack into the kiln equally quickly, and start the drying swiftly using temperatures below 30º C until the wood reaches about 20 per cent MC. Thereafter dry as normal for furniture grade wood. This particular cause of discolouration can affect a range of other wood species such as beech, ash, alder, birch, et cetera. Slainte.

*Gard WF, et al, (2010) Discolouration of timber in connection with drying, Cost Action E53, Working Group 2 [Online] Available at: <http://www.coste53.net/downloads/Literature/Discolouration%20of%20timber%20in%20connection%20with%20drying/Discolouration_of_timber_in_connection_with_drying.pdf> [Accessed May 10, 2013]

 

[BRYAN]

Thankfully this is something I won't be using for anything serious, just used as temporary support hot melt chucks etc.
I can now see where some of the stuff I've inherited in the past that had been machined got the dark colour streaks from.

I've yet to get to the Holly I've got stored/drying, not very optimistic that it will be usable in its natural colour state.

I once read in a timber conversion book that holly should be dried vertically. I can't remember the reason though.