How not to pinch bar?

[460Ted]

Working on a fallen 2.5 foot diameter oak from the recent rains.

Can someone describe the best way to make a cut, below the 1st Y, through the trunk, without pinching the bar?

 

[ShoerFast]

Cutting so the cut will get wider, or cutting from the tension side - the compression is the key.

With out a picture, a wedge is your frend.

 

[ehgauss]

Once you have some clearance above the top of the bar/chain, drive in a plastic wedge. It'll keep the kerf from closing up until you're all the way through (and have the chain buried in the ground). Sorry about the feeble attempt at humor. Actually, if you're careful, once you have the wedge(s) in, you can ease up as you approach the ground and pull out leaving only a little to be broken off as you roll the log.

 

[460Ted]

Cutting so the cut will get wider, or cutting from the tension side - the compression is the key.

With out a picture, a wedge is your frend.

The base of the tree has been cut from the stump and is laying on the ground. The tree is still on an uphill angle with the top of the tree suspending the trunk a couple feet off the ground.

I would like to make a cut to get the whole trunk flat on the ground, but I'm afraid it'll pinch.

Should I cut from the top down say a 1/3 of the way, and then finish from the bottom up?

 

[blewgrass]

cut down and keep a closeeye on the kerf. once you see it starting to close switch to the underside.

 

[460Ted]

cut down and keep a closeeye on the kerf. once you see it starting to close switch to the underside.

At that point, would you recommend putting a wedge in the top or not?

 

[AT sawyer]

If you have top bind (kerf closes as you cut in from the top) you don't need to use the wedge unless you intend to hold the kerf open and keep cutting down into the bind. A tree under a lot of compression can spit a wedge, particularly if you hammer on it once it's tight. If you leave your bar in the tree while doing this you are asking for trouble. Better to start in from the bottom once the top cut begins to close, but offset your cut 1/2" to the stable side of the tree. That way, when the trunk falls (assuming the trunk will drop), it won't take your saw down with it. If your tree is nearly flat on the ground, you'll have to bore cut down then back up into the tension.

 

[Labman]

....

I would like to make a cut to get the whole trunk flat on the ground, but I'm afraid it'll pinch. ....

I always cut some big limbs off and put them under the trunk to hold it off the ground. Space them right, and you have tension to cut down without binding. Watch the kerf. It may only look like you have tension. If not tension, at least you have space to cut up form the bottom.

 

[blewgrass]

At that point, would you recommend putting a wedge in the top or not?

naw. i only use wedges for felling. once you start the undercut you'll see the topkerf close. on small trees you can usually just cut right on up through, but on a bigger tree like yours i'd go a little more cautiously. cut, take the saw out, put on the chainbrake, kick the trunk, see if it'll snap. repeat until tree is down.
always try to keep an eye on the forces in the tree. is the whole trunk in compression, how's that branch going to snap if i cut it here, should i be straddling this, etc. after a while it becomes second nature on how to safely cut any given tree.
as for cutting all the way through when the log is lying on the ground, i find it's easiest to cut most of the way through and then roll the log and finish my cuts. i hate dulling my chains.

 

[460Ted]

If you have top bind (kerf closes as you cut in from the top) you don't need to use the wedge unless you intend to hold the kerf open and keep cutting down into the bind. A tree under a lot of compression can spit a wedge, particularly if you hammer on it once it's tight. If you leave your bar in the tree while doing this you are asking for trouble. Better to start in from the bottom once the top cut begins to close, but offset your cut 1/2" to the stable side of the tree. That way, when the trunk falls (assuming the trunk will drop), it won't take your saw down with it. If your tree is nearly flat on the ground, you'll have to bore cut down then back up into the tension.

What if there isn't a stable side? What if both sides will want to drop?

 

[Frank Boyer]

Is there a possiblity that the tree will come down hill when cut? You need to watch for movement from the up hill side.

 

[460Ted]

Thanks for the help guys. Everything worked out great! You were right, keeping an eye on the kurf is the key. I didn't pinch the bar at all on any of the cuts and there was no need to use a wedge.

You can see how big this tree was by the damage it did to the homeowner's car, when it fell over from the storms.

 

[AT sawyer]

OBE now, but you can always block a cut like that so it won't fall more than a few inches. If it was a live tree before falling, you might also have gotten a sit-back into the rootball depending on how close to the bole you made the cut.

 

[Brian VT]

I've got 2' a blowdown I want to cut up for firewood. The trunk is still attached to the stump where it snapped about 2' off the ground. The top is on the ground and stable.
To get the base of the trunk on the ground I plan to cut from the top until I see the kerf want to close, then cut from the bottom. I guess I should make the bottom cut 1/2" further away from the stump just as if I was felling a standing tree ? Would there be any benefit to cutting a wedge out of the top cut like you would to fell ?
I haven't done much cutting with the top of the bar and I definitely don't feel as confident or safe. Any tips ?

 

[AT sawyer]

Without seeing the tree, I can't say for sure how it will react. If any part of the original trunk is still attached to the stump it may want to rise, depending on how close to the stump you make your cut. I don't often cut V-notches unless I'm dropping a hung-up leaner and want some control on the speed at which the trunk falls-- center of gravity can apply to such a cut, so any plan is subject to change once the saw starts into the wood. Beware of pushback on your saw if you're not used to undercutting-- keep a tight grip on your saw and your RPMs up when you begin your undercut.

 

[treeslayer]

all good advice but, (and just in case this has not already been done)
seems like everyone is concentrating on the one point, finishing a cut in pressurized wood. I would unload the tree first. cut ALL the weight off, and back to the trunk. then start making cuts on the trunk. if it starts to pinch, simply move to a new cut.
I'll cut a tree up walking in circles around it, taking what I can get, until I can easily finish the log.
using wedges is always smart, I carry several. And making a bunch of halfcuts until one easily finishes, then rolling over the ones that need finishing. A peavy or cant hook is important.
I carry 2 big peavys to the job when neccessary, or possible.
Whats my hurry ? I got all day to do it right.

pinch a bar and have to replace it? or twist a chain? or grab a second saw, and drop the log on the stuck saw? or fall off, or under the log, and end up in an ambulance or a helicopter?

I've seen guys do all that while working hurricanes. opcorn: opcorn:

 

[Brian VT]

Beware of pushback on your saw if you're not used to undercutting-- keep a tight grip on your saw and your RPMs up when you begin your undercut.

That's what I'm nervous about. I picture it pushing back and then the tip catching on the way out and kicking it up. That, or the tree taking the saw to the ground with it.
When the trunk starts to come down during the undercut do you usually keep cutting right up through or do you back out to assess, come back in if needed, and keep nipping at the hinge until you can kick it down ?

 

[Brian VT]

I would unload the tree first. cut ALL the weight off, and back to the trunk. then start making cuts on the trunk.

It's a clean trunk. Picture a utility pole with one end on the ground and the other on a 2' high stump.
You're saying I might be better to my make firewood-length cuts as deep as is practical while the trunk is suspended and this will slowly lower it to the ground ? I'm ok with that. Then I wouldn't have to undercut. What if it doesn't get to the ground but it's now low enough that I couldn't do an undercut ? I suppose I could stick something under it before I started, but what if that wasn't practical at the time ? I'm just trying to milk you guys for advice on many scenarios. Every tree and situation is different, right ?

 

[Brian VT]

or fall off, or under the log, and end up in an ambulance or a helicopter?

How's that one go ? I don't want to find out for myself.

 

[Nailsbeats]

Bore cut.

I don't think anyone has mentioned it, so I will put it on the table.

I usually attack this situation with a bore cut. drop down 4-5 inches below the top of the log and bore all the way through then cut down until you are finnished. If a whole tree is laying down and you are cutting at the butt, the log will usually open at the bottom as you finnish the cut. If so, you can trip the strap of wood that's left by cutting up from the bottom.

You could cut from the bottom up the whole way, but the bore cut allows you to not have to get your bar under the log to start the cut.

Edit: Looks like AT Sawyer already mention this method.