Spalted Oak

[DrHenley]

I have a woodpile in the back yard, and some of the wood has been exposed to the elements for over ten years. I got to looking through there to see if any pretty wood had managed to survive for making knife scales, and I found some.

But, while cutting through the rotted sapwood to get to some pretty heartwood that was solid as a rock, I discovered some spalting. Some of it is spectacular.

I read a lot about spalted maple and other woods but not much about oak.

I've tried stabilizing it with Bondo wood hardener and epoxy wood finish, but without a vacuum chamber I'm not getting complete saturation. Plus, I'm not really pleased with how it turned out. So I've sent samples to a knifemaker friend who is going to run a test batch for me using a vacuum chamber and Cactus Juice wood stabilizer.

Here is one of the pieces treated with Bondo Wood Hardener

And here is an untreated piece

Honestly, I've never seen anything like this before.

I'm thinking about using it to make chef's knives for my sisters for Christmas presents. If properly stabilized with Cactus Juice, will it be dishwasher safe?

 

[Matt Rochester]

Might be dishwasher safe but I still don’t recommend it. It’s a terrible environment for knives, other than butter knives. The temps are not good for some epoxies and the edge beating around on other utensils is not good either. Best bet is to send it off(K&G finishing) and keep it out of the dishwasher. Wood looks nice. Just cut a rectangle that’s 1”x5” out of a sheet of paper and hold it over some spots on the wood to get a feel of the finished product. Lots of wood looks figured in large pieces but when you cut it down to handle size there’s not much figure to it.

 

[milkbaby]

That wood looks awesome, pretty nice find from an old woodpile! That oak will most probably take up a good amount of stabilizing resin, as I've found stabilized oak is much heavier than natural (non-stabilized).

As Matt said above, still not a good idea to put it in the dishwasher. It's not good for knives in general, but if somebody wants to use the dishwasher, then you're probably best off choosing a synthetic material like G10. The stabilized wood will be a lot more resistant to movement but it's not turned into 100% resin.

 

[DrHenley]

I would never put my knives in the dishwasher, but once they leave my hands I have no control over what people do with them. I can recommend not putting them in the dishwasher, but...

There will be wood scales, I don't do plastic, G10, micarta, etc. I have some honey locust that I was going to use, it's just not as pretty. They make fence posts out of untreated honey locust, fungi can't attack it and termites have a hard time attacking it. Heck, even my chainsaw had a hard time attacking it - sparks were flying when I cut it.

 

[weo]

I'd send it to K&G. That looks pretty good, I'd use it. My brother told me he has put his knives with K&G stabilized maple in the dishwasher occasionally and so far no problems.

while cutting through the rotted sapwood to get to some pretty heartwood that was solid as a rock, I discovered some spalting.

My question is how rotten/soft the spalted portions are. In all the maple I've done, I found that if it is spongy enough that I can poke a thumbnail into the wood, there is a risk for some cracking to occur when sending to K&G for stabilizing.

 

[Hengelo_77]

Beautiful wood!

Apparantly it is the hot air of the drying cycle an the end of the dish washing that is most harmfull.
Give her an Ikea knifw if shw wants to put it in the dish washer

 

[lanternnate]

My question is how rotten/soft the spalted portions are. In all the maple I've done, I found that if it is spongy enough that I can poke a thumbnail into the wood, there is a risk for some cracking to occur when sending to K&G for stabilizing.

The wood may have been too green still when you sent it. The first step of stabilizing is to bake the wood to fully dry it out so there isn’t moisture to block the resin uptake. If your pieces still had too much moisture content, that quick dry could have caused the cracks.

Edit: The bake is at least the process for home stabilizing. I do not know K&G’s process, but assume it is similar because there is a significant difference in the resin penetration between a piece that got the pre bake and one that didn’t in my own attempts.

 

[DrHenley]

All of it has been baked at 175 degrees in the oven for an hour. It was pretty wet and spongy at first but now it's all fairly hard. Maybe "stiff" would be a better word because you can poke a thumbnail in parts of it. But some parts of it are rock hard, especially the spalting lines. A number of pieces came apart after baking. Elmer's Wood Glue is marvelous stuff LOL.

There are two types which are represented in the pictures above. In the first picture, it is the outermost layer of heartwood at a knot and I could probably use it without stabilizing. In the second picture it is sapwood and much softer and more porous and completely useless without stabilizing.

 

[DrHenley]

Give her an Ikea knifw if shw wants to put it in the dish washer

Well I've already bought the steel to make the knives and have finished one of them already. (I have three sisters) So it's a bit late for that. The only decision is what wood to use for the scales. I thought the spalted oak would be pretty,special but the honey locust will be as durable if not more durable than rosewood.

 

[TRfromMT]

Spalted Oak can come out beautiful. It can have some bugs and holes, and K&G can get the best result by using the right kind of resin to fill the holes better. I wouldn't suspect that Spalted Oak would fare any better or worse than any other properly stabilized wood in the dishwasher (that is to say, it would be bad for them, same as any other).

These were done a year ago or so. This was some fantastic material in person.

View attachment 1138569 View attachment 1138570

 

[weo]

The wood may have been too green still when you sent it.

While this is definitely something to watch out for, it was not the issue in the experience I was describing. Wood will eventually rot out enough to loose structural integrity even when completely dry.

The first step of stabilizing is to bake the wood to fully dry it out so there isn’t moisture to block the resin uptake.

I'd edit this slightly to say that the first step is to merely dry the wood to get it under 7% moisture. Baking is only one way to get there.

 

[weo]

I do not know K&G’s process, but assume it is similar because there is a significant difference in the resin penetration between a piece that got the pre bake and one that didn’t in my own attempts.

K&G uses enormous pressure to force penetration of their resin, opposite of the home stabilizer's use of a vacuum.

 

[weo]

A number of pieces came apart after baking. Elmer's Wood Glue is marvelous stuff LOL.

Are you planning on stabilizing/using these pieces? If so, let me know how they turn out. I never would have considered trying this.

a knot and I could probably use it without stabilizing. In the second picture it is sapwood and much softer and more porous and completely useless without stabilizing.

Personally, I'd stabilize all of it...

 

[Horsewright]

Dishwasher = abuse. I'd send it to K and G too. Too nice of wood not too.

 

[Ken H>]

All of it has been baked at 175 degrees in the oven for an hour.

Not hot enough - bake at 212°F for a few hrs. Got to reach boiling point of water to really get the wood dry. That is some really NICE wood. Properly done Cactus Juice will give 100% penetration and the finished blocks will sink in water. K&G is also a GREAT choice and not that much more expensive than Cactus Juice.

 

[lanternnate]

K&G uses enormous pressure to force penetration of their resin, opposite of the home stabilizer's use of a vacuum.

Pressure only speeds up the resin uptake process AFTER vacuum. The wood, resin, and air around it are going to reach equilibrium either way. You can’t force any more resin in than there is space for it. K&G uses a pressurization cycle because they are doing large volumes and need to shorten the process. If the block has been under sufficient vacuum the same resin penetration is available by properly giving it time.

I'd edit this slightly to say that the first step is to merely dry the wood to get it under 7% moisture. Baking is only one way to get there.

If you follow the guidelines for using cactus juice, it is actually to aim for under 5%. Which is generally less than can be measured by a moisture reader. Most standard air dried wood will be closer to 10% because of being at the moisture equilibrium of the surrounding air. The instructions with cactus juice are to be dry to that 10% range at least before starting, then bake at 220 F for 24hrs to get down lower. Then seal in ziplock or similar to prevent major moisture uptake during cooling. Then stabilize. If it’s too green when you do the bake it will warp and or crack. Obviously if it’s rotten it’s rotten and there is nothing to reverse that

 

[milkbaby]

All of it has been baked at 175 degrees in the oven for an hour.

As you can see from the other replies, it should be baked longer at higher temps. Ideally you would measure the weight and can stop when the weight stabilizes, i.e. baking isn't driving off water anymore.

Some woods work good with cactus juice and garage stabilization because the wood is porous enough and not so dense as to make resin uptake difficult. The vacuum process draws air out of the wood so resin can enter. Some woods are problematic because they are rather dense (desert ironwood) or have natural oils that interfere with resin polymerization (cocobolo). Most species of oak shouldn't be a problem tho.

Knife handles were made for centuries with natural wood, not stabilized wood. Stabilizing just gives us the choice to use some woods that otherwise wouldn't have the physical characteristics suitable for a handle, like being hard enough or being stable enough. Obviously, you want to stop the spalting from continuing and to harden softer parts of that wood.

To me, wood is the most beautiful material for a knife handle. I joke that I only keep making knives to justify collecting more wood. But if a relative is going to mistreat a knife you made for them, just make it but be prepared to do any repairs necessary in the future.

 

[DrHenley]

Are you planning on stabilizing/using these pieces? If so, let me know how they turn out. I never would have considered trying this.

Yes, one of the sample pieces that my friend is going to use Cactus Juice on was glued back together. Too bad you can't use Elmer's Wood Glue to stabilize wood. Heat resistant and UV resistant.

On the subject of Elmer's. I accidentally spilled a drop of it on a blade and didn't notice it until it had hardened. This was a highly polished stainless steel blade... I thought I would be able to just peel it off. NOPE. It was stuck so hard I had to use steel wool to wear it down.

That got me thinking about using it to glue scales. I'm going to try it!

 

[Hengelo_77]

The heat from an oven will kill all fungus that creates the spalting, tho I'd be carefull with a lot of heat at once.
I had a handle crack during glue-up because I placed it next to a heater

 

[DrHenley]

Two sets of the spalted oak scales have been stabilized with Cactus Juice. I put one set on a knife today, and I'll let the epoxy harden overnight and finish it tomorrow and then take some pictures. It looks spectacular!

I'm going to encapsulate the handle in an epoxy finish made for bar tops. That should eliminate any gaps, although there probably won't be any. But it will make a water tight finish for the handle.