- Joined
- Dec 27, 2013
- Messages
- 2,655
Hey Guys. A comment I get from time to time is "i only use stabilized woods, they are more durable and suitable for hard use knives" And as someone who has worked with a LOT of cocobolo and kingwood, I was skeptical about this. Can stabilized woods really be that much more durable? So i made a simple experiment to find out. I got 4 blocks of wood, one Cocobolo, one kingwood, one stabilized walnut "K&G" and one desert ironwood. I tried to pick relatively straight grained woods, though the walnut had a VERY small amount of curl in it "This will be important later"
I then went to the engineering building at my school late one night, and began dropping blocks of wood off the roof. I started at 1 story, then 2 and ended up at the 4th story, dropping blocks of wood off for the better part of two hours "I ran a LOT of stairs"
And here are my results!
The blocks at the start of this
1 story drop: Minor scuffing. No damage
2 story: same
3 Story: The desert ironwood has started to devolpe a crack running its length, some corners show minor curshing
4 story drop #2
A large chunk broke out of the corner of the desert ironwood. Upon examination, it seems to follow and area of figure and grain runout. Other blocks are more or less in shape, walnut shows the worst corner damage. Coco is slightly dented in, but kingwood remains almost completely unharmed.
4 story drop #6
Another corner has broken out of the desert ironwood, a small sliver broke out of the walnut as well. It seems to have been a bit of curl just at the corner, no rough edges simply where the fibers pulled apart. One corner of the cocobolo is badly dented, the kingwood shows a small amount of crushed fibers on the very apex of a corner
4 story drop #10
Large crack running diagonally through stabilized walnut at about the middle point. it seems to have followed a line of light curl, spider web crack is seen on the face. Looks like some grain run out. A small piece, about 1/16 inch deep by 1/4 wide piece of kingwood has broken out of the corner. Cocobolo is showing crushed corners
4 story drop #11
Walnut has failed completely. Breaking along the crack. Upon inspection it is clear it was caused by grain run out. no fibers were really severed.
]
4 story drop #19
Cocobolo corner tears out. Again, following an area of grain runout. Its was nearly 11:30 and i was tired, so i called this as the end of the test
What does this all tell us?
Well for one thing, wood is REALLY strong! I was throwing these blocks off a 4th story for a long time. And most of the damage was very light. All and all there should be little to no worry about the durability of wood. You would have to be a serious klutz to break a wooded handle. If there are no corners and only rounded edges, it would be incredibly difficult to break.
It also shows that the actual strength of the wood is rather unimportant. The grain is what matter. I didnt expect to ever break the straight grained cocobolo and kingwood. The damage we saw was only at the corners and area of grain run out. And the walnut only failed after 10 drops of a 4 story building, and even then only by breaking across an area of grain runout. But this is important. We rarely stabilize perfectly straight grained blocks of wood, its almost always going to be curly, burled or otherwise figured pieces of wood. Though i would like to restate, 10 drops is a LOT of punishment.
It also shows some of brittle nature of desert ironwood. My assumption is that this wood was not perfectly dried "It was bought as a mostly dry slab and examined for visible cracks before testing" and i assume micro cracks began to propagate through the wood. I didnt have any professionally dried wood to test.
The rosewoods stood up amazingly well, taking very little damage, and i think if i had made the corners of all the block into ovaloids there would have been almost no damage at all.
Next up is going to be moisture testing when i get home. I will be submerging blocks in water at different temps for different periods of time, observing weight gain, expansion and relative rates of expansion as well as drying them in a 110 degree kiln to test their performance in a desert like environment.
I then went to the engineering building at my school late one night, and began dropping blocks of wood off the roof. I started at 1 story, then 2 and ended up at the 4th story, dropping blocks of wood off for the better part of two hours "I ran a LOT of stairs"
And here are my results!
The blocks at the start of this
1 story drop: Minor scuffing. No damage
2 story: same
3 Story: The desert ironwood has started to devolpe a crack running its length, some corners show minor curshing
4 story drop #2
A large chunk broke out of the corner of the desert ironwood. Upon examination, it seems to follow and area of figure and grain runout. Other blocks are more or less in shape, walnut shows the worst corner damage. Coco is slightly dented in, but kingwood remains almost completely unharmed.
4 story drop #6
Another corner has broken out of the desert ironwood, a small sliver broke out of the walnut as well. It seems to have been a bit of curl just at the corner, no rough edges simply where the fibers pulled apart. One corner of the cocobolo is badly dented, the kingwood shows a small amount of crushed fibers on the very apex of a corner
4 story drop #10
Large crack running diagonally through stabilized walnut at about the middle point. it seems to have followed a line of light curl, spider web crack is seen on the face. Looks like some grain run out. A small piece, about 1/16 inch deep by 1/4 wide piece of kingwood has broken out of the corner. Cocobolo is showing crushed corners
4 story drop #11
Walnut has failed completely. Breaking along the crack. Upon inspection it is clear it was caused by grain run out. no fibers were really severed.
4 story drop #19
Cocobolo corner tears out. Again, following an area of grain runout. Its was nearly 11:30 and i was tired, so i called this as the end of the test
What does this all tell us?
Well for one thing, wood is REALLY strong! I was throwing these blocks off a 4th story for a long time. And most of the damage was very light. All and all there should be little to no worry about the durability of wood. You would have to be a serious klutz to break a wooded handle. If there are no corners and only rounded edges, it would be incredibly difficult to break.
It also shows that the actual strength of the wood is rather unimportant. The grain is what matter. I didnt expect to ever break the straight grained cocobolo and kingwood. The damage we saw was only at the corners and area of grain run out. And the walnut only failed after 10 drops of a 4 story building, and even then only by breaking across an area of grain runout. But this is important. We rarely stabilize perfectly straight grained blocks of wood, its almost always going to be curly, burled or otherwise figured pieces of wood. Though i would like to restate, 10 drops is a LOT of punishment.
It also shows some of brittle nature of desert ironwood. My assumption is that this wood was not perfectly dried "It was bought as a mostly dry slab and examined for visible cracks before testing" and i assume micro cracks began to propagate through the wood. I didnt have any professionally dried wood to test.
The rosewoods stood up amazingly well, taking very little damage, and i think if i had made the corners of all the block into ovaloids there would have been almost no damage at all.
Next up is going to be moisture testing when i get home. I will be submerging blocks in water at different temps for different periods of time, observing weight gain, expansion and relative rates of expansion as well as drying them in a 110 degree kiln to test their performance in a desert like environment.
BW , did you calculate how many steps you walk up and down 
