Re: Sharpening ripping chains advice needed

[Chris Head]

Glad you moved the subject here Mr Hood!

Your question is actually alot more complicated than just saying 'do this, do that'.

I think the file size is 7/32 and unless you're really experienced using a file guide to ensure the top and side plate of each tooth is sharpened accurately is an absolute must. Both guides sit on the chain and control how the file is introduced to the tooth. The first type is a roller guide and the second a flat guide. I would suggest the flat guide would be appropriate if you're unused to sharpening by hand. The flat guide has angles marked on the back of it to help you, although I would doubt that ripchain angles are marked.

It's difficult for me to explain properly in words how to sharpen a chain properly but I'll have a go.

The easiest way is to clamp the chainsaw by the bar in an engineering vice, make sure the jaws of the vice are centred on the bar otherwise the chain won't turn. Clamp the saw with the engine to your left to start with.

Turn the chain and have a look at each tooth, find the shortest one and start from there, use a vernier caliper if you're unsure.

What you are trying to achieve is each cutter sharpened to exactly the same angle and length. I would suggest that you start at 10 degrees, if you don't have a 10 degree mark on the flat file then mark one on with a permanent marker.

Introduce the file to the tooth and sharpen with nice even strokes, with the angle that is marked on the top of the file guide parrallel to the bar. Start with say, two or three strokes and then check the underneath of the top plate and the side plate to ensure there is clean metal showing over the whole of the tooth. Make sure you brush/blow the swarf from the chain regulary, you'll know a nice clean cut from the file when you feel it. Until you're competent check the length of each cutter with the vernier caliper. Try and be economic with how much metal you take off the first cutter as the length of that one will dictate the length of the rest of the cutters, it is vital with ripping chains that they are sharpened absolutely accurately. Other types of chain are a little more tolerant.

Once you've finished one side, turn the saw around and do the same on the other side...BUT...this is what I call the 'backhand' side of the chain, you'll find that the action is a little different and you won't naturally be able to apply the same pressure as you did on the 'forehand' side of the chain, so you may well find that you need another stroke or two of the file to get the same result....again check that each tooth is the same length and angle as the last. Once you've finished sharpening the cutters it's onto the next thing.

Being able to sharpen a chainsaw is an absolute must for anyone who uses one, a blunt chain will need unnatural forces put on the saw, the chain and the bar, greatly increasing risks of injury and breakdown.

If I'm carving all day I would expect to be sharpening my three main saws perhaps three or four times easch per day and the two detail saws perhaps every other day, OK it takes a little practice, but what happens if you hit something, blunt the chain and your dealer is 1/2 hour away? It takes perhaps 5 - 10 minutes to sharpen up.

That'll do for the mo, the other important factors with are, depth of cut, bar wear, chain tension, timber species and dryness' (moisture content) and bar length vs engine power. And then there's fundamental maintence...I'll write more tomorrow.

Edit; I forgot to ask Robin, have you ever tried to increase the flexibilty of your timber production and products by taking the saw out of the mill and freehand ripping?