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Chainsaws : Sharpening

Today on Repairs101: I’m going to show you how to throw a quick edge on your chainsaws. Using nothing but a couple of files – the way you do it out in the bush.

Chain tension

OK so one of the keys to getting your chain sharpened correctly is getting the chain tension right. So I’d ask you to please look at my other film “Chainsaws : Correct Chain Tension” before you watch this one. Set up your chain tension correctly first and then watch what follows here.

OK the first thing you’re going to need is, of course, a work surface. If you’re at home or at the shop you know you can throw it up on your workbench. If you’re out in the bush find a nice comfortable work station like the deck of your truck. Or the tailgate or a log or a stump or whatever. I don’t know, some guys don’t mind using the hood of their truck for a workbench.

Power tools

So the first thing I should talk about is that there are all kinds of time saving devices. Like this Dremel tool with a rotary stone on the end of it. And they are going to make light work out of it. And there are all kinds of jigs that you can buy nowadays. Little round ones that you can lay on the top. There’s all kinds of table-top jigs that you can use to hold your rotary tool in place.

Now I’ll give you that that’s a lot easier than doing it by hand. But if you’re out in the bush, that’s not going to be an option, now is it? So the best way to learn really is the old fashioned way.

Hand filing

If you’re a weekend saw user : a rat-tail file, a flat file, a file holder, a file guide. That’s pretty much it. It’d all fit in your pocket. Although I sure don’t recommend you carry that stuff in your pocket. Especially if you’re in the woods working with saws. You don’t want to be carrying stuff like that around on you. Keep it in a tool bag or a tool box and keep that handy.

You’re going to need a rat-tail file the same size as your chain – in this case it’s 7/32. You know I’d encourage anybody to use a brand new file. Oh I understand trying to save money for sure but you’ve got to pick your battles. Try cleaning it up on a “file card”, this is called a file card. OK it looks like a brush for cats but it’s not it’s for cleaning files, just like that. So if you can, try cleaning it up but you know they’re not that expensive. For the aggravation it’s going to cost you: just chuck it and get yourself a new one. I’ve seen guys try and get decades of use out of a two dollar file and I just don’t understand.

File guides

Alright so this file guide here fits in your tool bag. You can carry it around you know on the job if you’re out in the bush it’s not too much to carry around. It does give you a really great accurate idea of what angles to cut. So if I’ve chosen the thirty degree angle what I want to do then is line up that score line on the guide with the bar. And then you can see it’s giving me a basis for a thirty degree angle. Just go down the line to the next one and it’s offset at thirty-five degrees.

The tip of this chisel here has been blunted off OK it’s obviously hit something hard. Perhaps a rock, perhaps a nail, perhaps a piece of chain link fence. The only solution you’ve got there is to clean it up to the point where the tooth is basically restored. It’s going to be considerably shorter if you take it all the way back to get rid of the damaged point. But you know, to have one tooth that’s a different length than all the rest isn’t going to affect your performance or the straightness of your cuts.

Once you’ve got three or four teeth that are damaged… And got cut back and are different varying lengths from your other teeth… Well then you’re going to have it start to pull to one side perhaps if it’s not evenly balanced. Once you’ve got three, four, five teeth that are shot, then it’s time to get a new chain. In the meantime take your file and just push it back like this.

This tooth that was damaged here I’ve cut back to shorten it. Much shorter than this one over here, OK? So we’ll just do the other side now and then we’ll look at the rakers.

Raker height

OK so the idea is to take a straight edge and lay it across from the crest of one tooth to the crest of the same tooth in front of it and that of course being every other tooth is an opposite. So when you lay that out then you’ve got this height here of this raker. This raker you can’t really adjust for this way. You have to go up and check it against the next set of teeth. So I’m setting up my straight edge from chisel tip to chisel tip here and therefore being able to measure the height of that raker.

Now I can tell you right now that I’m holding a twenty thou feeler gauge in my hand and I can’t get it in there. Twenty thou is only two one-hundredths of an inch. Two one-hundredths of an inch of an inch not a lot of room so I would say we need to cut down these rakers. So I’m just going to take down the tip of the raker, just like that. That being the raker. I’m just going to take down the tip of it with my flat file. OK I’ll just do one from the other side there. Again: point to point. Take my feeler gauge. I can’t get it in there. I cannot feel a half a millimetre or twenty thou. Anyways so I’m just going to take it down a little bit.

You’re probably thinking. “How come he yea how come he says yea yea yea and he’s still using a dirty old flat file. Well: you’re right. I got a brand new one right I got a brand new one right here. Well OK I’ve used it once. Take it down. There you go twenty thou or half a millimetre. Easy.

1/2 mm

I’m not suggesting that you take a feeler gauge with you out into the bush. I’m just showing you how you would confirm that you had approximately a half a millimetre or twenty thou depth on your rakers to make sure the depth of your cut is about right. You don’t want to be too aggressive. You wouldn’t want a one millimetre bight I’ll tell you that. Because you’re just going to be pulling in too much. You’re going to be overworking the engine. You’re going to be overworking the chain, things are going to get heated up, you’re going to consume oil. You know? It’s just not going to be a good scene all in all.

OK check your angles and check your depths. OK this is why these kinds of guides exist and after you’ve used them for a few years. You start leaving them behind and just doing everything by eye and then checking afterwards. And that’s what I do I do them all by eye. I check afterwards, if I’m out on a couple of teeth I buff them up. I tweak the angle on them and I’m done.

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