Last week’s Gibson Chair class – Chris’s first ever – was a rousing success. Only one person broke an arm (it was Chris), and everyone left with a gorgeous new Gibson chair in Ulmus rubra – red elm (with a red oak back rest), ready for finish. (I’m fairly certain every one is using a clear finish – this wood is too pretty to paint!)
But there is one mystery: Some of the sticks loosed some yellow powder upon planing…and we can’t figure out what caused this. I admit to spending but a limited time looking…because I’m busy and surely someone reading this knows! One possibility is “Elm Yellows,” aka elm phloem necrosis – but as far as I can tell from my limited reading, that disease turns the leaves yellow; there’s no mention of powder in the wood. I should also say that it doesn’t seem to have weakened the wood. Also, the powder didn’t bleed more out of the pores after further planing and a wipe-down with a rag. We did not do a taste test.
So – can anyone explain?
Soft Wax 3.0
Post hole borers
Wikipedia has a note on red elm from 2011— “Once cured, the wood is also excellent for starting fires with the bow-drill method, as it grinds into a very fine flammable powder under friction.[citation needed]”
An internet search revealed a similar result from someone making elm cutting boards in the UK. They came up with “crystalized sap” as the cause. In this case the cutting board kept producing the yellow powder even after some sort of oiled finish was applied. This phenomenon was also seen by working pine by another woodworker.
My guess would be crystalized sap, but red elm also contains tyloses in the grain similar to white oak which gives red elm its good weather resistance.
“Only one person broke an arm (it was Chris)”
This was a bit confusing and worrying.
Crystalized sap/resin? Could be micro-crystaline resins/sap that have hardened and get crushed to a powder?
University of Minnesota Extension has and article and pictures confirming that Dutch Elm Disease (DED) can infect the tree beyond just the leave, causing yellowing and streaking in the sap wood, and if left uncorrected, into the whole tree. This yellow powder is most likely the tree creating tyloses plugs in attempt to stop the movement of the fungus in the tree’s vascular system. https://extension.umn.edu/plant-diseases/dutch-elm-disease
I suspect this is the cause of your mysterious yellow powder.
You probably already have but I thought I’d toss this out there, did you try contacting Richard Jones? Maybe he came across it in his research.
I’m afraid I can’t help. It’s not something I’ve come across, but it is an interesting phenomenon and it may be Nathan Lee’s link to the University of Minnesota Extension’s research paper has a plausible answer.
Lime Disease
Shouldn’t it be lemon disease?
When life gives you lemons, some make liquor, some make lemonade.
If you’re smart, you make both. Limoncello is made out of lemon zest, so there should be plenty left for lemonade.
So, is the zest in this instance elm shavings?
Crucible can now sell Elm Glitter!
I think it was something spilled on the part separate from the process at hand
It looks like pine pollen to me. It seems able to go anywhere air can go, including into the coarse grain of oak. Try looking at it with a loupe at 10x or 30x.
Turmeric. As to how it got there, it still remains a mystery.
I think it’s the woods reaction to the person rubbing it down. I’ve heard talk amongst the trees, especially the red oaks, you are on their list. You’ve been marked! Prepare to be pollenated!
Looks like cheeto powder 😀
Don’t know what it is, but I have some American elm from a Dutch elm disease killed tree where some of the sapwood dried to a yellowish colour as well.