Wood scales and warping issues... Quick question

REK Knives

REK Knives

Moderator
Knifemaker / Craftsman / Service Provider
Joined
Apr 3, 2011
Messages
5,798
Hey guys, I picked up some 'stabilized' bog oak from etsy a year ago or so because that was the only place I could find it at the time. Just got around to using it.

I lapped the scales flat prior to any machining/grind work, but when I got mostly done with them (and yes they get wet when I grind under coolant) I noticed they were bowing up in the thin sections at the ends.

My question - is this normal or was it just a cheap stabilizing job? I have some stabilized walnut burl from Greenberg woods here I was going to remake these with but I don't want to if it will have the same issues...

i-r2QFqfJ-X3.jpg

i-jmCBKzS-X4.jpg
 
I used some stabilized bog oak without issue, but I glued it to the tang. What you have looks great except for the gap of course.
 
While I don't have any experience with bog oak, I've had professionally stabilized maple bow on me after cutting a block in half to make scales.
 
weo said:
While I don't have any experience with bog oak, I've had professionally stabilized maple bow on me after cutting a block in half to make scales.
Click to expand...
Thanks! Yeah that's more what I'm wanting to know - if this is a general issue no matter what stabilized wood you use...
 
How did you split it? Bandsaw or table saw? I've found heat from a tablesaw can cause it to bow. Also any block can have internal stress. Once you spilt it you loose the strength and it bows. Stabilizing helps but doesn't prevent it. My thought is to split it and let it sit for a while.
Once its done moving flatten it.

then you glue on liners and it warps again.
 
scott kozub said:
How did you split it? Bandsaw or table saw? I've found heat from a tablesaw can cause it to bow. Also any block can have internal stress. Once you spilt it you loose the strength and it bows. Stabilizing helps but doesn't prevent it. My thought is to split it and let it sit for a while.
Once its done moving flatten it.

then you glue on liners and it warps again.
Click to expand...

That's interesting! I cut these on a bandsaw and then milled the back sides flat.
 
Never worked with bog oak but my guess is wet grinding the wood is the problem , only one side getting wet. Wetting one side of a piece of wood is a method woodworkers can use to flatten a cupped piece of wood. If I had to do it wet grinding ,wetting both sides may help ?
 
In my opinion, as someone who sells a lot of bog oak, its a little of both.

I highly doubt it was professionally stabilized by K&G, and so im sure you're experiencing more warpage than is standard in stabilized wood, but stabilized wood does move some.

Bog oak should be relatively stable as it isnt very figured and a good quartersawn piece should be naturally resistant to warping even before stabilizing.
 
How did you flatten the scales? A belt grinder will not be flat it will do that on the ends were the belt bunches up as it comes in contact with the wood, A disc grinder would be better but you still can get a bit of rocking at the ends if you aren’t careful, even lapping by hand on a plate can do that if the paper isn’t adhered to the plate or you have uneven pressure, I always flatten scales with and extra 1/4” on both ends that can be trimmed off just in case it lifts like that. You could still carefully flatten it back down on a surface plate then maybe put a liner on if you want to add some thickness
 
Greenberg Woods said:
In my opinion, as someone who sells a lot of bog oak, its a little of both.

I highly doubt it was professionally stabilized by K&G, and so im sure you're experiencing more warpage than is standard in stabilized wood, but stabilized wood does move some.

Bog oak should be relatively stable as it isnt very figured and a good quartersawn piece should be naturally resistant to warping even before stabilizing.
Click to expand...

I'm honestly not sure where it came from... It does sink when put in a cup of water though.

Do you think I'll have better luck with the circassian walnut burl I got from you? Or will wood warp in those thin cross sections regardless?

Joshua Fisher said:
How did you flatten the scales? A belt grinder will not be flat it will do that on the ends were the belt bunches up as it comes in contact with the wood, A disc grinder would be better but you still can get a bit of rocking at the ends if you aren’t careful, even lapping by hand on a plate can do that if the paper isn’t adhered to the plate or you have uneven pressure, I always flatten scales with and extra 1/4” on both ends that can be trimmed off just in case it lifts like that. You could still carefully flatten it back down on a surface plate then maybe put a liner on if you want to add some thickness
Click to expand...

I milled them flat initially and then checked on a granite plate afterwards and they were dead flat.

After the warping I lapped them flat on a diamond plate again, which prevented any rounding at the edges. Last night before I went to bed I dipped the handle in water (with the scales attached) this morning I'm having some pretty bad lifting at the ends which makes me think there may have been an issue with the stabilizing process.
 
But, stabilizing does not render wood waterproof. Water does penetrate, and I guess it does not surprise me there is warpage when you get them wet ... especially in thin cross section. If you wanted lack of reaction to water, I would go to a fully synthetic ... like G10 ...
 
Cushing H. said:
But, stabilizing does not render wood waterproof. Water does penetrate, and I guess it does not surprise me there is warpage when you get them wet ... especially in thin cross section. If you wanted lack of reaction to water, I would go to a fully synthetic ... like G10 ...
Click to expand...
Ahh good point, I thought stabilizing basically made the wood waterproof. My bad.
 
You must log in or register to reply here.
Back
Top