Stabilized wood scales are warping like bananas. Is it normal?

[Francisco Vaz]

Hey guys, going straight to the point im having problems with mostly maple. Since my handle work is mostly done using 3/8" scales (around 9mm) they are "randomly" warping.








It seems they are getting worse each day. About 1 month ago they werent this bad, mostly was flat, now they are warping each time more.


Does this means any mistake during stabilization or is this natural? I really thought stabilized woods were meant to be "stable" under most climates and not meant to warp like this.


Im really upset as i bought a big ammount of stabilized woods and now everytime i want to use them i must handpick the very few that didnt warped. Very frustrating.

 

[TheEdge01]

Hey guys, going straight to the point im having problems with mostly maple. Since my handle work is mostly done using 3/8" scales (around 9mm) they are "randomly" warping.


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It seems they are getting worse each day. About 1 month ago they werent this bad, mostly was flat, now they are warping each time more.


Does this means any mistake during stabilization or is this natural? I really thought stabilized woods were meant to be "stable" under most climates and not meant to warp like this.


Im really upset as i bought a big ammount of stabilized woods and now everytime i want to use them i must handpick the very few that didnt warped. Very frustrating.

I’d definitely call the stabilization process into question. I’ve had very few scales warp on me and they weren’t stabilized at all.

 

[ea42]

I wonder if they were just dyed and not actually stabilized. Or perhaps they weren't cured? I know resins like Cactus Juice have to be baked for some time in order to harden and cure them. Some folks just dowse blanks with super glue and call them stabilized, you definitely have to be careful with who you source them from.

Eric

 

[Francisco Vaz]

I wonder if they were just dyed and not actually stabilized. Or perhaps they weren't cured? I know resins like Cactus Juice have to be baked for some time in order to harden and cure them. Some folks just dowse blanks with super glue and call them stabilized, you definitely have to be careful with who you source them from.

Eric

It was not used cactus juice as far as i know.

Would you say stabilized wood wont warp like this?

 

[andybtruckin]

I had a bunch of scales stabilized. Everything went out flat. The Olivewood came back warped like in the OP's pictures. No dye, just stabilized.

 

[C_Claycomb]

Francisco Vaz
You show the red scales warping towards each other, (). Are those scales the two halves of a block, stabilised as a block, then cut in half with the cut line where the two scales meet?
I have always had wood stabilized as blocks. When I have had pieces of 19mm wide or less treated they warp without any additional cutting. If the wood was not fully dry, I would expect the outside to dry and shrink during processing, then when cut the scales would warp away from each other )(.

I once hade a 2”x2”x14” block of quilted maple clear stabilized, it came back not as a square, but a trapezoid. Wood definitely moves and it is hard to get it dry enough not to.

Anyone know if absorption of resin cause any swelling/expansion of dry wood?

Olive wood is notoriously difficult to get really dry. Also noted for internal stresses and tendency to warp.

 

[Alpha Knife Supply]

In thread like this, it would be beneficial if knifemakers posted who did the stabilizing. There is a huge difference between K&G stabilizing and home brew with a pickle jar and hand vacuum pump.

In my experience with K&G stabilized wood, the wood can move any direction while it is being stabilized. When we sold stabilized wood, we would dry the blocks for 4-12 weeks, depending on the species of wood. While drying we checked the moisture content frequently. Once dry, the blocks were sent to K&G. After stabilizing we let the blocks sit for a few weeks. At that point, we would cut scales and there was little to no dimensional change.

Buying wood that has been professionally dried and stabilized is not very expensive when you consider the time, effort and finished results.

Chuck

 

[Francisco Vaz]

In thread like this, it would be beneficial if knifemakers posted who did the stabilizing. There is a huge difference between K&G stabilizing and home brew with a pickle jar and hand vacuum pump.

In my experience with K&G stabilized wood, the wood can move any direction while it is being stabilized. When we sold stabilized wood, we would dry the blocks for 4-12 weeks, depending on the species of wood. While drying we checked the moisture content frequently. Once dry, the blocks were sent to K&G. After stabilizing we let the blocks sit for a few weeks. At that point, we would cut scales and there was little to no dimensional change.

Buying wood that has been professionally dried and stabilized is not very expensive when you consider the time, effort and finished results.

Chuck

The wood is stabilized in Brazil, by a very reputable wood supplier. He does this been almost a decade but i dont know what is going on. I reached him once to check about this and i was told this is normal and probably happens due the difference of density about the wood and the stabilizing resin.

I got stabilized wood from Raffir and even others from him and another supplier too and it didnt warped, so i dont think climate or temperature is the problem.

 

[Stacy E. Apelt - Bladesmith]

What Chuck said!

The stabilizing person and equipment makes a huge difference. Who did the work?

The condition of the wood before stabilizing is very important. Moisture content HAS to be below 10% and 7% is even better. A good stabilizing company will measure the moisture content of every block and set the wood aside for a week or put it in a drying cabinet to lower the moisture content if needed before stabilizing.

Scales cut from stabilized blocks can warp due to the internal stresses in blocks from stabilizing. This is normal, especially if the moisture content was higher than optimal when stabilized. After cutting the scales let them sit for a few months to warp if they are going to, and then flatten as needed. Getting them hot in sanding them flat or sanding after cutting the scales will tend to cause warp as well.

Olivewood will warp no matter what. Send the blocks in a bit oversize to allow re-squaring after the stabilizing. Other species of wood have similar problems.

 

[Francisco Vaz]

What Chuck said!

The stabilizing person and equipment makes a huge difference. Who did the work?

The condition of the wood before stabilizing is very important. Moisture content HAS to be below 10% and 7% is even better. A good stabilizing company will measure the moisture content of every block and set the wood aside for a week or put it in a drying cabinet to lower the moisture content if needed before stabilizing.

Scales cut from stabilized blocks can warp due to the internal stresses in blocks from stabilizing. This is normal, especially if the moisture content was higher than optimal when stabilized. After cutting the scales let them sit for a few months to warp if they are going to, and then flatten as needed. Getting them hot in sanding them flat or sanding after cutting the scales will tend to cause warp as well.

Olivewood will warp no matter what. Send the blocks in a bit oversize to allow re-squaring after the stabilizing. Other species of wood have similar problems.

Yes, the scales were cut from blocks.

I guess it makes sense due the internal stress because each block gives 3 scales

like: ( | )

The scale from the middle of the block did not warped, but the scales from the outside did like ( ) or ) (

Would this be the reason?

 

[Stacy E. Apelt - Bladesmith]

I forgot to ask what the wood was. Grain type and amount of distortion to the grain also affects warp.

 

[Greenberg Woods]

The wood appears to be box elder rather than classic maple. Box elder is in the same family, more prone to small burls bur also a little less stable than rock or big leaf maple.

Wood, espically burl wood can build up stresses over time which will be released by cutting. I would ask about the density of the blocks. If you could do the mass / volume that would give a pretty good indication as to the amount of resin penetration.

The other step would be if theres a scale you're willing to risk, pour some water on 1 side of a scale and see if the movement increases. That will tell you if the issue is internal stresses due to reactive wood or if the expansion/ contraction is whats causing the wood to move.

 

[Taz]

The stabilizing process can warp wood, which is why it is good to use a professional outfit (NOT CACTUS JUICE), let the blocks sit after stabilizing, slice the scales and let sit again. Stress built up in the wood may be released when in thinner sections, but should be stable after that and not move anymore unless you add stress to it when shaping (ie getting it too hot). My guess is the wood wasn't fully dried properly before stabilizing, or something went wrong during the process. Maybe the dyes threw off the resin curing?

I got a set of 30 "stabilized" blocks of wood sent to me by a store to use for an order to rehandle 30 kitchen knives for their store about 10 years ago. All 30 blocks were cut down into scales, then sanded flat, liners epoxied to them, epoxied to the tangs, shaped, polished, finished like I always do. This was over a couple month period. All 30 ended up moving, swelling, curling, shrinking, cracking, etc. a few months later after they were received by the store and most sold to customers. They were flat and nice when received at the store and then shipped and a couple months later, the emails started coming in! I had to re do them; the store provided more wood from a better supplier and I redid the handles. I put the messed up scales in the freezer and they would move with temp/humidity changes when they went into the freezer for a day or so and move again when they were brought back to room temp. The scales still move to this day and the wood is around 10 years old now, so they were never properly stabilized to begin with!

 

[Francisco Vaz]

The stabilizing process can warp wood, which is why it is good to use a professional outfit (NOT CACTUS JUICE), let the blocks sit after stabilizing, slice the scales and let sit again. Stress built up in the wood may be released when in thinner sections, but should be stable after that and not move anymore unless you add stress to it when shaping (ie getting it too hot). My guess is the wood wasn't fully dried properly before stabilizing, or something went wrong during the process. Maybe the dyes threw off the resin curing?

I got a set of 30 "stabilized" blocks of wood sent to me by a store to use for an order to rehandle 30 kitchen knives for their store about 10 years ago. All 30 blocks were cut down into scales, then sanded flat, liners epoxied to them, epoxied to the tangs, shaped, polished, finished like I always do. This was over a couple month period. All 30 ended up moving, swelling, curling, shrinking, cracking, etc. a few months later after they were received by the store and most sold to customers. They were flat and nice when received at the store and then shipped and a couple months later, the emails started coming in! I had to re do them; the store provided more wood from a better supplier and I redid the handles. I put the messed up scales in the freezer and they would move with temp/humidity changes when they went into the freezer for a day or so and move again when they were brought back to room temp. The scales still move to this day and the wood is around 10 years old now, so they were never properly stabilized to begin with!

god what a headache this must be! Thank god i didnt used these warped woods on handles yet. Since i do international shipments, returning a handle from a customer would be a nightmare of cost. Ill do some tests today with water and such as mentioned by Greenberg. Thank you a lot guys

 

[Francisco Vaz]

The wood appears to be box elder rather than classic maple. Box elder is in the same family, more prone to small burls bur also a little less stable than rock or big leaf maple.

Wood, espically burl wood can build up stresses over time which will be released by cutting. I would ask about the density of the blocks. If you could do the mass / volume that would give a pretty good indication as to the amount of resin penetration.

The other step would be if theres a scale you're willing to risk, pour some water on 1 side of a scale and see if the movement increases. That will tell you if the issue is internal stresses due to reactive wood or if the expansion/ contraction is whats causing the wood to move.

Do you think it does make sense to weight the wood and then pour it into water and then weight it again after 10 minutes to check how much of water did penetrated it? Ill just pour some water on one side of them to check

 

[Francisco Vaz]

Update: i just clamped them on a flat steel surface and put in the oven for 1 hour at 240f (116 celsius) and let they cool naturally inside it once i turned off.

They are straight at least for now. It seems it was internal stress from cutting scales out of the block (which was around 30mm thick). Ill keep checking and put some water on them to see it they warp again.

 

[stubbornforge]

The stabilizing process can warp wood, which is why it is good to use a professional outfit (NOT CACTUS JUICE), let the blocks sit after stabilizing, slice the scales and let sit again. Stress built up in the wood may be released when in thinner sections, but should be stable after that and not move anymore unless you add stress to it when shaping (ie getting it too hot). My guess is the wood wasn't fully dried properly before stabilizing, or something went wrong during the process.

I have received warped scales from professional stabilizer. In fact, at a higher rate than ones that I work on myself, but that could be just circumstantial. I would imagine the movement can be attributed to the structure of the individual pieces of wood.