On Dulling

[cory]

Today I had some problems with unexpected dulling of my chain. I was taking down a large box elder (3.5'x50'). In cutting a thick limb apart with the 372, where I wanted to cut was a cavity so to avoid the possibility of cutting through a critter home which have proven in the past to contain saw-dulling elements, I cut about 2' away from it. The resulting cut face showed porous, rotting wood, but nothing a creature could nest in so I figured I dodged that bullet. But the next limb undercut I made had me wondering if my saw suddenly went dull. And you know the axiom that if you think your saw Might be dull, well, it is dull?? But we were on a roll with the takedown at that point so I decided to keep going.... The next cut was to be a cracking down of a good sized limb to ease the falling impact on a septic field partially in the drop zone(no kerf or undercut, just a single cut from the top down so the limb would hinge down on the uncut/ breaking underside portion).Many of you know where this is going... In the process of making the cut, the limb barberchaired real badly cuz the saw wasn't cutting fast enough. No injuries or damage but it could have been very ugly.

So I switched saws and continued. But later, cutting into the rotten hollow trunk 25' up, the saw got totally dull though there was no sign of foreign objects, just rot and rotten dark brown mush/crud. I used the first-dulled saw to make the final felling cut and a bucking cut to avoid dulling a 3rd saw. It resulted in the ugliest stump ever, just seriously hacked up to try to get that heavily leaning spar to the ground.

So the only stuff that dulled the saws seemed to be just rot and brown gunk, no sign of animal homes or junk in the tree. So I'm wondering how rotting wood dulls a chain. I've always felt that cutting JUST wood, or what was recently wood, won't dull a chain.

Though it seems some rot you can cut through with impunity but some other rot will cook your edge?

 

[squisher]

Seems like if the rot is older, like the black gold rot, it's almost more like a soil and will dull your saw.

No matter what's done it the answer is the same, swap up saws or file up. Running dull sucks.

 

[sawinredneck]

Yup, or soil sucked up as the bark dries out, I've seen a lot of that in sandy soil.
Depending on how dead the tree was it might have had some hard spots in it as well. I've seen some odd things the last few years. Watching sparks fly on green Hedge, watching sparks fly on a standing dead Pine and killing four chains falling a standing dead Red Oak that was 24" at the base.

 

[CurSedVoyce]

Yup. Dirt and dull. you were cutting decomposing tree = dirt ...

 

[HolmenTree]

As I found over the years running semi chisel for overall arborist work is the most reliable chain to use. I found Carlton and Windsor semi chisel held an edge longer then Stihl or Oregons semi chisel.
But I have grown up since a young lad with chisel chain and just find its easier to file and I do love its agressive speed. Until one day I stuck a Oregon .325 semi chisel narrow kerf chain on my 346XP, after cutting a few sticks I stopped and looked twice thinking I had a .325 chisel on there. That little semi chisel is aggressive and seemed to take forever to get dull.

 

[woodworkingboy]

Some species of wood are more prone to pulling up minerals that are extremely hard on cutting edges. Maple and Horse Chestnut are that way. With Maple, if the wood is slabbed up and you are planing it, for example, the mineral deposits are visible as greenish to black dark spots. With the Horse Chestnut, it can be visible or not apparent. Since it wrecks havoc on both jointer/planer knives and fine quality hand plane steel, I assume it would be hard on saw chain as well.

 

[Al Smith]

I found the same thing inside of a basswood .It was just about like top soil .

Oh yeah it will dull the hell out of a chain in a heart beat .

 

[CurSedVoyce]

I cut dead nasty day in and out... Might as well stick the fuggen saw in the dirt. Result is the same.

 

[HolmenTree]

Pine likes to grow in sandy, rocky ground. I'm always touching up the chain with the file in that wood.
One advantage of the jackpine when I used to log by the tree length cord then later cubic meter, was it piled nice and loose with lots of airspace. Which gave me a bigger cord on my weekly scale when our scaler made his rounds.
Spruce was the opposite , much straighter and smooth barked and I got a "tighter scale", but production averaged out because the spruce is normally larger in length and diameter, plus easier to limb with the saw or skidder.

But I have cut wood on river delta ground and found the peaty organic soil didn't seem to bother my chain's cutting edge much at all. We have alot of limestone in our country and cutting that doesn't do alot of damage to the chain.
Now granite which we also have is another story

 

[HolmenTree]

I have found there is a fine balance in keeping the sawchain's side plate "hook" just right to keep your chain cutting fast even when a little dirt has taken some of the edge off.
Too much hook and you have too thin a cutting edge and just a wee bit of dirt will dull it quickly,or even some tree species knots can break off some of the working corners.
Not enough hook with a backslope because of lazy filing will not pull chips worth a crap when also dulled with only a wee bit of dirt.
Todays factory sawchain's grinds are quite aggressive right out of the box, not like years back when the angles were poor and barely an edge honed on them.

Just file the chain with the same sideplate angle from new and you will get more mileage between filings , some of you may have to use a file holder to keep your file at the right height for a "good hook" in your chain's sideplate.
The hook is the key.

 

[cory]

I never heard of trees sucking up minerals that are concentrated enough to act like, well, minerals and rocks in the tree. But maybe that is the case. I figured if a tree is composed of good clean wood, then as the tree rots and the wood turns to rot, the rot should be clean too, since it came from something clean. Wish I could tell bad, dulling rot, from harmless rot!

 

[Al Smith]

I'm not so certain the wood fibers don't contain some mineral content depending on the soil conditions .On that internal rot that looks like top soil I have no idea why it would be so abrasive but it is .

 

[woodworkingboy]

Cory, you actually do get easily visible little pockets of deposits in the wood. Easy to recognize, and everything around it is clean. As to why certain species are more prone to it is a mystery to me. When hand planing, areas where the deposits are are best left to last, if possible.

 

[cory]

Well, I'm learning something, from the House again. Maybe not the Why of it but at least the What.

 

[Porkbrick]

could another possibility be invertebrates? if, say, you have a tree with a rotted heart, would it be conceivable that earthworms/ants/termites actually move soil particles upwards into the stem? i know that just earthworms are responsible for a phenomenal amount of soil movement in the environment. just a thought. as to jays point about minerals in the wood, think about coral. they build their skeletons (and so do we) out of dissolved calcium and co2. minerals in wood are formed similarly.

 

[Tucker943]

Trees do absorb minerals that remain in the wood.

 

[woodworkingboy]

Sometimes you can even hear the sound of a cutting edge passing over a deposit. A little scratching sound.

 

[cory]

could another possibility be invertebrates? if, say, you have a tree with a rotted heart, would it be conceivable that earthworms/ants/termites actually move soil particles upwards into the stem? i know that just earthworms are responsible for a phenomenal amount of soil movement in the environment. just a thought. as to jays point about minerals in the wood, think about coral. they build their skeletons (and so do we) out of dissolved calcium and co2. minerals in wood are formed similarly.

I like it. Simple, plausible.

Although, I rarely find any invertebrates, other than slugs, in the rot/mush.

 

[Altissimus]

Squirels ... sorry Brian ... betweeen the the feces and gathered foodsstuffs left in cavaties .... equals DIRT

 

[HolmenTree]

I find large hardwood trees in customers yards that when years ago were multiple stems then grew into one stem. A lot of times I would be cutting through these stems and find a rock, gravel or dirt in the middle of it. I quess while those trees were young the landowner was doing landscaping some dirt was thrown on it, maybe shoveling snow and some gravel got thrown into the crotches also.

 

[cory]

yep. and years of leaf blowing around the trees can embed grit in the bark/crotches. But its the inside rot that has me, uh, stumped...

 

[Al Smith]

You can find about anything in a yard tree .Sometimes you can even find some treasures in a woods tree .I've never found a cat skeleton on a tree yet though .Maybe the hoot owls snatch them .

 

[Cobleskill]

I saw a nice clump of green grass in a crotch over the weekend. The neighbors have a bunch of Norway Spruce. I saw a seedling growing in a crotch of a Black Willow. I should have got a picture.