saw bar damaged after being pinched?

[Nutmeg Warrior]

Ok, so I am a total chainsaw newb and have been pinching the bar with some regularity. A couple of times it was really stuck and took some work to pry free. Now it seems the chain is somewhat difficult to pull along my hand (chain is not too tight), but it could be my imagination. I took the bar off and don't see anything obvious but I'm wondering if I did some damage. How do I check?

 

[smokinj]

I would run a big flat head screw driver down it.

 

[Jags]

Check the drive links of the chain for obvious signs of friction. There are tools that allow you to re-gap the bar.

 

[lukem]

Remove the bar from your saw. Take the chain and run 1 drive link down the bar groove all the way around to see if it "catches" any where. This checks for 1 bad spot.

If you don't find an isolated spot, your bar may be bent. Lay it on an extremely flat surface and make sure it is not bowed.

You can usually fix a single bad spot in a bar, but if it is bowed you're probably best off replacing it.

 

[NCFord]

Also look for "hot spots" on bar after running it hard. A single bad spot will show up pretty quick with the metal being disclored where it is dragging.

 

[Nutmeg Warrior]

All great suggestions. There is some recent discoloration along the bottom of the bar. Maybe that is the spot.

 

[smokinj]

You will feel the spot with a flat head quick enough, or buy the tool.

 

[Sean McGillicuddy]

Buy a new bar and keep that for a backup!

 

[Jack Fate]

Look at the drive side of the chain, ( back side ) look for bent drive teeth .

Buy new bar & chain , then you can try to correct the damage , then use as back up

You always need spare chains & bars anyway

And everything everybody else said

Good luck

 

[Nutmeg Warrior]

Yeah, I have spare chains. Maybe I will pick up a new bar. I can see how it would be useful.

 

[bogydave]

Check the drive sprocket too.
If getting a new bar, you should get a new drive sprocket. (or rim drive)
Not sure on your saw the type of drive .
(grease the needle bearings while in there).

 

[tomahawk]

I usually use the screwdriver trick.

Why are you pinching the bar so much though? I understand it happens from time to time but if it's happening enough to do damage to your equipment then you should try a different approach. Is it when you're falling the tree or bucking up the wood? If when falling then start to use some caution, you can do some major damage to yourself, your equipment or property. If when bucking then watch how the weight of the log is sitting in the cut area. It happens, but is avoidable most of the time if you slow it down some.

 

[Nutmeg Warrior]

I usually use the screwdriver trick.

Why are you pinching the bar so much though? I understand it happens from time to time but if it's happening enough to do damage to your equipment then you should try a different approach. Is it when you're falling the tree or bucking up the wood? If when falling then start to use some caution, you can do some major damage to yourself, your equipment or property. If when bucking then watch how the weight of the log is sitting in the cut area. It happens, but is avoidable most of the time if you slow it down some.

Thanks guys, screwdriver seems to have done the trick. Why am I pinching so much? Good question. I don't have a lot of experience cutting firewood. I had no problems with logs laying flat on the ground. Pinching started when I began work on a huge downed maple which is >2' diameter at the base. This heavy tree is laying across a stone wall and it has been very difficult to determine where the pressure points are. I've had some luck doing relief cuts, but some times I am misreading and getting the saw stuck. I picked up some plastic wedges and hope these will help with the bigger cuts.

 

[TreePointer]

Great idea on the wedges. I always have at least one when I cut.

Sometimes even seasoned cutters can be fooled by how a tree looks. What seems to be the tension side of a log can actually be a compression and vice versa. One skill you'll develop is watching the kerf as you buck. As soon as it starts to close, that's your cue to pull out.

 

[Ram 1500 with an axe...]

Newbies should not be cutting big downed trees in or near middle spots, you should be cutting at end and moving over as you continue cutting, also somehow lifting the tree up a bit so the log has somewhere to go when cut through. Cutting thick maple with too much wood on both sides will pinch everytime with a newbie doing it. I learned that same hard lesson...

 

[Jags]

I learned that same hard lesson...

The real question is "how did you learn it"? Experience only happens in one way.

 

[tomahawk]

If one end was being supported by a stone wall like he said, then I can see where it could happen easily. You look at it and think to cut it in the middle to start getting it off the wall, then about mid way through the weight pushes it back together. This is where I would start from the underside and make a cut, but I would never suggest that to someone without a fair amount of experience because of the kickbacks that can happen. Sometimes it just comes down to what you feel comfortable doing with the chainsaw in your hand. I have the fortune of having a father-in-law who was a logger and has shown me the best way to attack most situations. I do like the wedge idea though, at least you could get your chain back out even if it did start to pinch.

 

[Nutmeg Warrior]

Thanks for the wisdom guys. I've been cutting from the top down, but this tree is a complex beast the way it is suspended by branches and the rock wall. I have also been cutting from the underside when I think that's appropriate. I read that if the tree is suspended on both ends, I should make a small cut on top and do the majority of the cutting from the underside. However even following this advice I sometimes pinch in that first relief cut. Should I try doing the entire cut from the underside sometimes?

 

[StihlHead]

All great suggestions. There is some recent discoloration along the bottom of the bar. Maybe that is the spot.

Discoloration of the bar metal (bluing) is due to excessive heat, and that is usually due to not enough oil on the bar. That may be because the bar is too long for the saw's oil pump, the oil pump is set too low (if it is adjustable), or far more commonly, the oil flow is blocked someplace, usually at the location of the oil hole at the base of the bar.

As for pinching bars, it happens. Some guys on this list claim they have never pinched a bar. I have my doubts about that. Old saying here in Oregon is that you are now an experienced faller until you have made a back cut and had the tree spin a full 180 degrees, fall backwards and land right on your saw. I have usually pinched bars when bucking and I expected the log to collapse downward when cut, but a hidden branch made the log spring upward and pinch the bar. Or a tree I am falling pinches the back cut. It happens. With inboard clutch saws, I remove the power head and put on another B&C and cut above or below and pull the pinched B&C out. Use your judgment as to where the tension is in the log and make a small cut on the side that you think the log will pinch down (or up) on, and then cut from the side that you expect the log to move (where it will open up when cut). The bar may pinch if you make the first cut too deep, or if the tension is the opposite of what you expected and it gets pinched in the second/final cut.

There are several bar tools for truing (correctly restoring the bar to function properly). One is a flat file or a bench grinder for filing off the burs that form on the outer edges of the bar rails. You should look for them and file them off before they chip off and take pieces of the bar with them. File/grind the burs off at a 45 degree angle. Then you can flatten/even the bar rails with a file tool designed for that, or as I do, use a ski edge tuning file (same tool, really). You can also use a belt sander or the side of a grinding wheel to do that. There are also tools for restoring the rails of the bar if they are pinched, or as you have done, use a screwdriver to release any pinched areas of the bar. Basic maintenance for a bar is to unclog the oil holes, grease the tip sprocket if there is a grease hole there, file the burs off, and flip them over so that you wear them evenly from the top and bottom. Most of the wear on a bar will be on the bottom rails where most of the pressure for cutting is applied.

 

[bogydave]

There are times when I only cut from the bottom up or from one side,
I make all the easy cuts & remove all the wood I can before cutting the possible pinch cuts.
The shorter & lighter the log is, the easier to move it around & avoid a pinched stuck saw.

Sometimes I lay rounds under the log to catch it when it drops. 1st cut might be in 1/2, then start cutting rounds.
Difficult to say how & where to cut with out standing there.

Usually I work from the top down.

 

[TreePointer]

Nutmeg Warrior, if you haven't already done so, watch ALL of the Stihl chainsaw videos. IMO, they can be a bit long, but they are full of good tips. One of those tips may keep you from damaging your saw or yourself.

Stihl Video Library - Chainsaw Safety Operation & Maintenance

"Chapter 9: Limbing and Bucking" should be helpful in this discussion.

 

[Foragefarmer]

Sounds like you need a second saw to cut yourself out of a jam on occasion. I know I carry two into the woods every time. It is when you don't bring that second saw that you need it the most.

 

[Jack Fate]

Thanks for the wisdom guys. I've been cutting from the top down, but this tree is a complex beast the way it is suspended by branches and the rock wall. I have also been cutting from the underside when I think that's appropriate. I read that if the tree is suspended on both ends, I should make a small cut on top and do the majority of the cutting from the underside. However even following this advice I sometimes pinch in that first relief cut. Should I try doing the entire cut from the underside sometimes?

Hey your thinking & asking good questions here ,I really feel for you situation here, It's though (sounds like it I can't see it )wall damaged ? neighbors? I see why your having your problems.I do rigging & equipment but I got that ,you may not . Sorry to say it costs to learn (everyone) but you could end up being great at it.
What you have said so far sounds logical

Oh on the bent drive side teeth on the chain if that happens and I'M NOT SAYING your bar /chain pinch did this to yours , your most likely not gonna bend them back ,they seem to be hardened and only bend once that said if the rest of the chain is good it can be spliced with new if you find a place with the stuff to do it

Good luck

 

[TreePointer]

Sounds like you need a second saw to cut yourself out of a jam on occasion. I know I carry two into the woods every time. It is when you don't bring that second saw that you need it the most.

Good plan. I try to have a backup saw for every saw I own, so I'm still looking for a backup to my latest backup.

 

[Jack Fate]

The real question is "how did you learn it"? Experience only happens in one way.

anyone not making mistakes isn't getting anything done

there's a better one than that but I can't remember it