Hand file question

[Philbert]

How do you tell when your hook is too aggressive?

More ‘hook’ will make your chain ‘self-feed’ into the wood. Too much will make the chain ‘grabby’ and hard to control.

Some of this depends on the type of wood being cut.

But more hook will create a thinner top plate cutting bevel angle, which will not hold up as well.

Trade offs.

I’m seeing worn dull working corners.

Full-chisel chain often dulls first at the corners. There is just less metal behind them to support them as they slam into the wood approximately 20 times per second.

Semi-chisel chain has a sturdier working corner.

I’m using 5/32 file called for by the chain manufacturer. Oregon file guide with a small shim to get low enough to reach the gullet.

As noted, filing / shaping / cleaning out the gullet is a separate task.

Philbert

 

[J D]

As noted those drive links are worn considerably at the back end & your bar needs dressing. This could be the result of poor lubrication or leaning on a dull chain

 

[maowwg]

As noted those drive links are worn considerably at the back end & your bar needs dressing. This could be the result of poor lubrication or leaning on a dull chain

Yes sir! You are correct. On one side of the bar the grove is worn wider than it should be. On the other it's still "true" or "tight" enough. So I flipped the bar and put the "tight' grove down where most of the horizontal bucking cuts occur. I dressed the edges a bit with file. It's about done..... I bought the saw used for $25 and put in lines / carb etc. The bar / chain was worn badly when I got it. However, it does oil so I'll just finish wearing out that bar and chain cutting stumps.

 

[maowwg]

My muffler modded 42cc PP220 uses 3/8 low profile chain and I set the depth dauges to 0.025" . It has been a good saw for the 18 years that I have owned it . Do you know what the depth gauge setting is that you like on your 2550 ?

Thanks Scottr
I don't quite know where I stand with the depth gauges. However, this situation with getting very dull very fast after cutting well for a while has happened on the chain in question with the photos of the hooks and the next chain I put on the saw after consuming that original chain. With the guide and spacer, the hooks are very consistent from tooth to tooth and from chain to chain.

I think what I'll do is leave the depth gauges alone, file the next time with thinner spacer on my filing guide, bringing the file higher up, and creating a slightly less aggressive hook and then see what happens. If it doesn't bit, I can put the depth gauges and the depth gauge filing guide back to work. With the added muffler mod power, the 42cc motor doesn't stagger or stall, it just piles up chips. Maybe I got too aggressive for what a LP 3/8 chain should be doing.

P.S. the PP220 is a decent saw. I've found two 2550's and a 2450 for $25, $20 and $20 respectively, so I've got 3 cylinders to wear out and a pile of replacement part between the three of them. But the PP220 with the chrome cylinder is a nice choice in the role of a beater, brush cutting, stump chopping, loan it to your brother in law for him to wreck, light duty workhorse, junker chainsaw. Everyone should have an "expendable" chain saw. Or maybe three of them to practice my maintenance work on....

 

[scottr]

maowwg , way bick in 1988 I bought my first chainsaw and the Oregon file and handle guide set for the 3/8 low profile chain . That along with the operators manual helped me learn how to sharpen my low profile chain . I never thought about removing the gullet hump until I read a thread here about cleaning out the gullets . That guide does a excellant job of holding the file 20% above the cutter top plate to get the proper hook and support for the chrome cutting edge . My chain sharpening instructions said to drop the file handle down to create a 10* angle and it makes a sharp durable cutting chain . For years I used a flat bar and wire feeler gauge to set the depth gauges . I use a half used up round file to remove the hump from the gullet and then it is easy to sweep a new 5/32 " diameter file from the last half stroke of free hand sharpening the cutter forward and down through the gullet . About every third sharpening I use the file guide .
Scott

 

[HumBurner]

Yes sir! You are correct. On one side of the bar the grove is worn wider than it should be. On the other it's still "true" or "tight" enough. So I flipped the bar and put the "tight' grove down where most of the horizontal bucking cuts occur. I dressed the edges a bit with file. It's about done..... I bought the saw used for $25 and put in lines / carb etc. The bar / chain was worn badly when I got it. However, it does oil so I'll just finish wearing out that bar and chain cutting stumps.

First, you should swap the position of the bar often. Some do it as much as every tank or two for most even wear.

Not only do you have to file burrs off (flush with) the sides of the bar/rails, but you also need to dress the top of the rails to square. A bar should be able to stand on its rails on a flat surface. The tail of the bar is often the worst spot for me, but that can vary.

 

[maowwg]

First, you should swap the position of the bar often. Some do it as much as every tank or two for most even wear.

Not only do you have to file burrs off (flush with) the sides of the bar/rails, but you also need to dress the top of the rails to square. A bar should be able to stand on its rails on a flat surface. The tail of the bar is often the worst spot for me, but that can vary.

 

[maowwg]

I agree. But when a bar is shot when it comes to you with a rail grove that’s worn loose there’s not much to do other than running it until the less worn side is worn out too.

I knocked off the burr when I changed chains. But I didn’t bother dressing the bar much.

 

[cookies]

I agree. But when a bar is shot when it comes to you with a rail grove that’s worn loose there’s not much to do other than running it until the less worn side is worn out too.

I knocked off the burr when I changed chains. But I didn’t bother dressing the bar much.

Running worn out bars results in unevenly worn chains that rapidly dull cutters, replace the bar and chain and your problems should stop. Even when you flip the bar the chain is going to ride uneven on the other side and likely rock side to side enough that its hitting the sides of log in the upper part of the cut.

 

[maowwg]

Running worn out bars results in unevenly worn chains that rapidly dull cutters, replace the bar and chain and your problems should stop. Even when you flip the bar the chain is going to ride uneven on the other side and likely rock side to side enough that its hitting the sides of log in the upper part of the cut.

Well that’s an interesting idea!

OK, I’ll give it a try and let you know. Could it be that simple? Never occurred to me that sliding through the top curf unsupported would dull something hard enough to tear out chips on the bottom of the cut.

 

[scottr]

Well that’s an interesting idea!

OK, I’ll give it a try and let you know. Could it be that simple? Never occurred to me that sliding through the top curf unsupported would dull something hard enough to tear out chips on the bottom of the cut.

A sharp chain severs and zips out chips . If you google there's a video that shows how a chain works that will help .

 

[Big_Eddy]

In my experience if a chain quickly changes from cutting to dull, there was dirt hiding on the underside of the log, or the chain hit the ground. A well sharpened chisel chain in clean wood will easily outlast a tank of gas, usually two. Semi sometimes even three.

But just one cut through a clump of mud frozen to the bottom of a log, and it’s back to the bench.

 

[HumBurner]

I agree. But when a bar is shot when it comes to you with a rail grove that’s worn loose there’s not much to do other than running it until the less worn side is worn out too.

I knocked off the burr when I changed chains. But I didn’t bother dressing the bar much.

If the bar was shot when it came to you, why did you use it? Why not clean it up, proper, and close the rails? That's asking for headaches and extra wear/damage to the chain.


Any amount of burr on the bar will affect cutting slightly. You had a decent amount on there, which could partially explain the lack of cutting ability and the tendency to dull.


I still think evening out where the gullet meets the rest of the cutter will help you. Looking back at the photos, you can see where the profile of your tooth is not nicely rounded a third or less of the way down from the top plate. It also leads me to think you have some play in your file during the stroke.

 

[Mad Professor]

I use a vertical belt sander to true up bars that are getting ugly. Otherwise when I'm home doing a chain, I just put them in a vice and draw file them after I take off any burrs. It also helps to clean the groove every few sharpening when you have the chain off.

 

[maowwg]

Thank you to everyone for their kind advice. Appreciate the additional feedback on bar maintenance.

For now, I’m going to simply replace the bar and chain, and throw a raker gauge on the next chain. I’ll back off slightly on the hook and see what happens.

 

[Mad Professor]

Thank you to everyone for their kind advice. Appreciate the additional feedback on bar maintenance.

For now, I’m going to simply replace the bar and chain, and throw a raker gauge on the next chain. I’ll back off slightly on the hook and see what happens.

save the old setup for cutting stumps off and stuff with fence wire in it

 

[thenne1713]

How do you tell when your hook is too aggressive? Noticed that I will be cutting through decent sized logs and after maybe 3/4 of a tank, my chain will go dull.

I expect a saw to go dull but it’s how fast it goes from chips to dust that I’m questioning and wondering if it’s my filing geometry.

If you have slightly too much hook, does the chain go dull right away as the top plate is bent down, or do you get 3/4 of a tank out of that filing and suddenly go dull?

I’m not seeing bent top plates when resharpening. I’m seeing worn dull working corners. What I’m questioning is how I can cut strong for 3/4 of a tank, see the slightest indication of saw dust in my chips and 3 or 4 cuts later be throwing sawdust and 2 or 3 more cuts and I’m dull.

I’m bucking 14 to 18 inch logs with an 18 inch low profile 3/8 .50 chain. It happened more noticeable with the full chisel chain than the semi chisel.

OTHER Influences on how fast a chain goes dull can be geography/ weather, SAND embedded bark from high winds; SAWYER staying out of mud; MUD embedded into bark from log HANDLING; and too acute an angle on cutter.

 

[maowwg]

I backed off slightly on the hook and the chain (same worn bar) cuts very well and holds its edge much longer. Problem solved.

 

[HumBurner]

I backed off slightly on the hook and the chain (same worn bar) cuts very well and holds its edge much longer. Problem solved.

Awesome!


Hook is all relative to the seemingly infinite other factors involved.

I'm wearing two of my .43 chains down to toothpicks, currently. One is missing 5 cutters on a 16" full comp chain, four on one side. With proper tailoring of the hook, depth gauge, and keeping the bar cleaned and dressed, it cuts pretty close to a new chain still.

 

[maowwg]

I also took your advice and closed the rails then hand filed the bar edges parallel. Took about half hour. Not perfect but much better.
Last night I worked about 3 hours. Cut great. Still replacing the bar, but with the work I did there’s no doubt in my mind I recovered all the time and efforts on bar maintenance within that 3 hours. Good advice. I’ve always viewed the bars on an 18 inch Poulan as essentially disposable. I still do at $20 to $25, as doubling the life only saves $10. Still its a good exercise. Probably like sharpening the chain where I will touch up more often so it’s not such a problem.