Grinder hardened chains

[turnkey4099]

Can a chain that has been overheated on a grinder to the point it can't be filed ever be corrected? As in grinding back past the hardened edge or does the entire tooth harden?

I ran into an almost new 28" chain while working through my 'to-be-sharpened' stack. It had been overheated.

 

[Jhenderson]

I've run into some Oregon chains that had 1 or more hard teeth right out of the box. I don't own a chain grinder so I put a cut off wheel in a 4 1/2 inch hand held grinder and take 1/32 off the offending tooth. That gets me to something a file will sharpen.

 

[cantoo]

Harry, I have that happen once in awhile too. I blamed it on dirty chains. I tried a bunch of things including new grinding wheels and soaking the chains in varasol. Ended up taking more time than it would be to just hand file them. So now I have chains that are burned and have to be sharpened on the grinder and chains that I'm only hand filing. The hand filed chains last longer and cut better.

 

[crowbuster]

cantoo reflects my experience as well. I don't file much anymore. Swap em out and keep cuttin

 

[turnkey4099]

cantoo reflects my experience as well. I don't file much anymore. Swap em out and keep cuttin

I have way too many chains but still can't make myself through away a chain with lots of life left in it IF it could be filed.

I quit taking chains to be sharpened. Every shop I tried has ruined at least one chain. It only takes me around 10 minutes to file a 28" chain and that includes mounting saw in vice and attaching the file guide. Well worth the time vice spending $10 for some ham handed SOB to overheat it on a grinder.

 

[hseII]

I have way too many chains but still can't make myself through away a chain with lots of life left in it IF it could be filed.

I quit taking chains to be sharpened. Every shop I tried has ruined at least one chain. It only takes me around 10 minutes to file a 28" chain and that includes mounting saw in vice and attaching the file guide. Well worth the time vice spending $10 for some ham handed SOB to overheat it on a grinder.

What file guide do you use?

 

[sawjunky23]

I have way too many chains but still can't make myself through away a chain with lots of life left in it IF it could be filed.

I quit taking chains to be sharpened. Every shop I tried has ruined at least one chain. It only takes me around 10 minutes to file a 28" chain and that includes mounting saw in vice and attaching the file guide. Well worth the time vice spending $10 for some ham handed SOB to overheat it on a grinder.

I hand file all of my chains. I feel they cut as good if not better and they last a lot longer. I will admit that I boogered up a chain or two while I was learning to file them though. But I had the local saw shop, make me up a loop and I took it back to him to sharpen it, the chain only made it three sharpenings . Plus the money you get into a chain paying to have it sharpened adds up quick. I bought a crappy grinder from HF, I use it on chains once they get rocked or really bad.

 

[Swamp Yankee]

Can a chain that has been overheated on a grinder to the point it can't be filed ever be corrected? As in grinding back past the hardened edge or does the entire tooth harden?

Most likely salvageable,

I've had multiple chains over the years, either my own, and/or a friend or relative, that exhibited this problem. In most cases the root cause was the person grinding took way to much material off in a single pass overheating the tooth (teeth). That said, never underestimate the heat generated by a dull chain forced to cut over the full length of the bar.

I put the chain on my grinder and set the wheel for each tooth as I go. Takes awhile for sure. What I try to accomplish is to just kiss the tooth with the wheel. Oftentimes if .010 to .020 of material is removed you'll be far enough back to be out of the heat effected zone and can resume filling. Sometimes a couple of the skin cuts may be necessary to get out of the hardened section, it will depend on each tooth, which is why it takes so long to repair a chain.

If the chain has plenty of life left and you have access to grinder it's certainly worth the effort to try.

Take Care

 

[Sandhill Crane]

The hand filed chains last longer and cut better.

I used to take my hand saws and chains to an old guy down the road. He hand filed and set the saws, and hand filed the chains. He reminded me of my grandfather, who made money as best he could cleaning a church, hand caining (spelling) chair seats, and renting out two rooms in the up stairs of their house, to college students in Delhi, New York. Anyway, when the old man down the road from me took ill and no longer sharpened stuff, I dropped my chains off at a shop where they sharpened with a grinder. Within the month I bought a Grandberg jig and some files, and never looked back.
I replaced that twenty plus year old jig this spring with a TSC knock-off, then mail ordered a new Grandberg. The knock-off went in the trash.

This past Friday I bought a Stihl hand file system with two round files and a flat file for the rakers. $45.00 I've used it once and like it so far. Although, if you buy one, check the files. The tip on one of mine was broken so the first few strokes the file floated about. Replaced it and good to go. I did put a torpedo level on it a couple times just to get the proper feel for horizontal level with the bar clamped in a bench vise. Tried the chain out on some twenty inch oak logs I had set aside. Very happy with it, but it will take many sharpening to tell if still cuts straight, and keeps the rakers down. Anything new is going to take some time to get it right.

The thing about hand filing is you can do it often with little effort or trouble. A dull chain gets hot. That's hard on the chain and the bar, harder on you, and certainly more dangerous. I sharpen often, about every cord or three fuelings, or the first sign of beginning to dull, and use plastic wedges when needed, cutting rounds, to keep from pinching the bar and chain. A sharp chain puts a smile on your face every time you touch it to a log.

I also use cutting fluid (Tap Magic) on my hand files.
Moved my cutting area away from the house/garage this spring, so I need to get another vise and mount it to a piece of plank that I can clamp on the quad.

 

[turnkey4099]

What file guide do you use?

An Oregon, it sets all the angles, also has a stop that, if used, makes all teeth the same lenght. I don't use it, just count strokes, usually 5 per tooth unless it has been rocked. That guide is around 30 years old. I inherited my dad's back in 76. It was pretty well worn but still useable. BIL gave me the Oregon when he decided firewood was too much work

I looked at the combo file & ?set? with two files. Nope, not for me, looks like a poor excuse for a multipurpose tool. I have never seen a multipurpose tool do any one thing well. When needed I use the Stihl raker guide that leaves the raker at .035. I cut mostly soft woods.

When to file? As soon as I realize that I am 'riding' the saw. If it won't pull throu gh with no pressue, it needs filing.

I carry a minimum of 2 extra chains for every saw on the truck (usually 3) and change out when needed - file when back at the shop.

I keep my "ready" (sharp) chains in ziploc baggies. If it is in a baggy I know it has been sharped.

One of the things that took me the longest time to leard was "Throw away a file when it no longer cuts well". I buy them by the dozen and I saw today that I need another dozen 7/32"

 

[crowbuster]

I agree turnkey, got my own grinder after that very thing happened to me. I was done with them doing my chains. I go to the next chain and sharpen at home later now. just saves me time while cutting.

 

[Philbert]

Can a chain that has been overheated on a grinder to the point it can't be filed ever be corrected? As in grinding back past the hardened edge or does the entire tooth harden?

Yes.

Philbert

 

[Philbert]

Filing vs. grinding is a separate discussion.

Avoiding overheating is a separate discussion.

To restore a 'grinder hardened' cutter, simply grind past it without over heating it again.

Philbert

 

[turnkey4099]

Filing vs. grinding is a separate discussion.

Avoiding overheating is a separate discussion.

To restore a 'grinder hardened' cutter, simply grind past it without over heating it again.

Philbert

Thanks. Looks like I need to get the old HF grinder running again.

 

[Philbert]

Overheating usually results from impatient grinding, or from using dull or dirty wheels. Lots of light taps, and frequent dressing of the wheels, is key to preventing.

Good wheels are also key for grinding past the heat damaged cutters - the newer HF grinders have very fine (brown?) wheels which do not cut as well as the coarser 'pink' wheels (some of the older HF grinders had better wheels). Some better quality replacement wheels will fit the mini-grinders; they are definitely available for the full sized, Oregon type grinders:

http://www.arboristsite.com/community/threads/hf-chain-grinder-thread.268303/
http://www.arboristsite.com/community/threads/resinoid-grinder-wheels.256733/

*Not saying that resinoid wheels are 'better' - just an interesting discussion on grinding wheels in that thread. I normally use brand name 'pink' wheels (Oregon, Molemab, Tecomec, etc.)

So now I have chains that are burned and have to be sharpened on the grinder and chains that I'm only hand filing.

If I had a bunch of grinder hardened loops I would try to gradually bring them back, over the course of several sharpenings, instead of trying to do this all at once. They will still cut with the grinder hardened edges, so you will get some additional work life out of them, and you avoid the risk of overheating again by hogging off a bunch of metal.

If someone wants to file right away, then I would grind past the hardened area, testing with a sharp file to verify that I am back into the base metal.

JMHO

Philbert

 

[muddstopper]

My first grinder was one of the cheapo plastic types you buy at HF anf Northerntool and such places. It was cheap plastic, one preset angle and so flimsy that the chain stop/positioner never cut each tooth to the same length. Worthless for sharpening full chisel chains since you couldnt set the 10* up angle needed. I bought one of the Orgeon clones at Northern a couple of years ago. With it I am able to set all the angles for proper grinding and It does a really good job of keeping my chains sharp. Of course not all was well with the grinder right out of the box. Slop in the chain clamp which took some modifying to hold the chain tight being the biggie.. Over all, for $100, worth every penny. I also have one of the Sthil combo sets that files the cutters and the rakers at the same time. Any one that doesnt like one of those just dont know how to use it in my opinion. two or three strokes on a dull chain and its back to cutting like new. I keep it with in my truck for touch ups in the woods, but hardly ever use it since I keep multiple chains on hand and usually sharpen all at the same time on the grinder when back at home.

 

[cantoo]

Philbert, theses chains actually has a blue burr on them and they wouldn't cut crap. The wheel was black and I'm sure when I posted pics on here it was suggested to buy a new wheel and clean chains more often. I bought a new wheel but the time cleaning chains isn't worth it to me. I still use the wheel just not too often.

 

[Philbert]

I burned some chains while learning to sharpen. I turned some blue. I turned some black. I have had the chrome peel back on some. As long as there was clean metal behind that, I was able to grind past that and make them cut.

When people first get a grinder, I encourage them to 'practice' on some scrap chain, including intentionally burning some cutters to see what it takes - then to see what it takes to not do that.

Philbert

 

[Marine5068]

I hand file all of my chains. I feel they cut as good if not better and they last a lot longer. I will admit that I boogered up a chain or two while I was learning to file them though. But I had the local saw shop, make me up a loop and I took it back to him to sharpen it, the chain only made it three sharpenings . Plus the money you get into a chain paying to have it sharpened adds up quick. I bought a crappy grinder from HF, I use it on chains once they get rocked or really bad.

I do the same...

 

[tla100]

Yeah, I hand file all of mine, usually after a couple tanks thru, I will touch em up. Then when done for the day, blow em off and clamp in big vice on welding table and run file over cutters before I put them away.

I do have an el-cheap0 HF grinder. I get good results with it also, as long as you use the same motion on all cutters it works well. The flex in it does not bother me. I come straight down with it and hardly take any off, then use the little bit of flex to take a bit more off and it cleans them up well. It has the wheel that came with it, I have heard there are better ones out there, but it works ok. Only use it on pretty bad chains.