Saw filing help?

[Tony Shea]

I have been rehabbing an old diston 5 1/2tpi rip saw lately and having a bit of an issue getting the teeth right. The teeth had the issue of alternating height differences. Every other tooth was shorter/higher than the other. I thought jointing the teeth until the file started flattening all the teeth would remedy the problem. But after continuing on like normal shaping, setting, and sharpening the teeth again ended up in the same condition. With the teeth this way it seems like the saw doesn't want to track straight.

What am I missing about fixing this issue, I would assume it must be a fairly common condition in saws. This is only my third attempt at sharpening an old saw into working condition and my first in which the teeth didn't start out so well.

[Paul Incognito]

Tony,
I've sharpened a few saws and haven't run into this problem.
The first thing that comes to mind is the set of the teeth. Are you sure they're set the same on both sides?
I generally sharpen rip saws all from one side, this means that one side will have to be stoned a little bit to get the burr off the tooth edge.
I'm definitely interested in hearing from some more experienced sharpeners as I'm bound to run into a similar problem eventually.
PI

[Andrew Gibson]

As for the tall and short teeth, I would joint the saw then file every other tooth a pass or two to see if that brought the teeth into alignment. If that made it worse I would re joint and file only the opposite teeth (I have not figured out which side of the tooth I need to file to bring it's tip down, thats why I say pic a side, and if it dosnt work, try the other). On a slightly different note. I file from one side of the saw, no flipping the saw. I find that if I flip the saw I can never get the tooth geometry right, epically on x-cut saws... So all my filing is done from the left side. All my saws are filed like this and they all cust just fine.

as for the tracking problem, most likely you have more set on one side then the other. I have found that it seems like when setting that sometimes when setting the second side it wants to pull the first side back toward the middle... maybe it's just me.

two fix this you can either try resetting the teeth on the side that the saw tracks away from, or you can stone the side that the saw tracks toward, removing a bit of set from that side.

All that being said I only have a bit more experience then you do, maybe a dozen saws, and one retoothed from scratch... But I hope that helps.

[george wilson]

Somehow my post dissappeared. I think you might be seeing an illusion caused by holding the file on an uphill angle while filing. It will make alternating teeth SEEM shorter,but they are not. Place a straight edge down the tips of the teeth and see if they all actually touch it. File holding the file horizontal,and the illusion will go away.

[Tony Shea]

I'm sure that it is not an illusion. I noticed the teeth were alternating in height originally by laying the teeth on my bench. And after sharpening the same problem came up. I may just need to joint the teeth a bit more and spend more time shaping the teeth. And I'm also pretty confident that the teeth height is more the problem with the tracking than the improper set. I think that it tracks bad due to all the teeth on one side of the saw is doing the cuttting.

[Andrew Gibson]

And I'm also pretty confident that the teeth height is more the problem with the tracking than the improper set. I think that it tracks bad due to all the teeth on one side of the saw is doing the cuttting.

That would do it.

[george wilson]

I have definitely seen saws with MUCH higher teeth on 1 side,as well as having MUCH more set on 1 side.

We were called over to the housewright's yard some years ago. Their pit saw wasn't cutting right. The supervisor(who got fired eventually) was ready to throw the saw(which cost a lot of money) away,and buy a new one. He almost acted like the blade had a curse on it.:) I found that they had filed one side of the saw 1/8" shorter than the other side. The set was all on one side,too. I told them what to do. Several days later,they asked us(Jon and me) back. They had gotten the saw better,but I told them again what needed to be done. Finally,they got the teeth and their sets right,and the saw worked just fine.

I couldn't understand how they could have used a pit saw for over 25 years,and let it get in such ridiculous condition,and then couldn't look at it and see what was wrong!!!!! Please don't go to Williamsburg and repeat this story to them.

[Paul Incognito]

How about if you joint the teeth until the high ones are flattened without going far enough to hit the low ones? Then focus the filing on the front or back side of the flattened teeth as necessary to achieve consistent gullet depth and keep everything the same height. Maybe?
PI

[Jim Koepke]

All my saws are filed like this and they all cust just fine.

Cussed just fine?… Freudian typo?:D

The last saw I sharpened had a problem like this. It required jointing a few times before the teeth agreed on the same height.

I will file from one side when I am making new teeth. If there is set on the teeth, then the saw gets flipped. This doesn't mean that filing from one side will not work for a rip saw. If it works for you, then what more can one ask?

Learning to bias the cut of the file to one side of the gullet or the other without changing the rake is part of rehabilitating old saws.

My last saw seemed to cut fine until it got to a certain group of teeth, then it would buck and bounce. One more light rejointing followed by a light filing of the teeth and it now cuts like it should.

Just my 176261.

jtk

[Marv Werner]

Hi Tony,

In your situation, you should first focus on the depth of the gullets. The short teeth have deeper gullets. So after you joint the teeth so the file is just touching the shortest teeth, do most all your filing on the teeth that were long and file until that big flat is equal to the flat on the short teeth. The short ones won't all be the same, some will have flats.

Do all your filing from one side of the blade. What you are actually doing, is reshaping the teeth.

After you have all the gullets close to the same depth, joint the teeth again. This time you will want flats on all the teeth. This time when you file, file every other tooth and file half of the flat off the teeth on each side of the file. Then file the alternating teeth and file off the other half of the flats.

Try to maintain a consistent rake angle at all times. I suggest you use an 8 degree rake angle.

Depending on how bad the teeth are when you start reshaping, you might have to make two or three and maybe even four passes before you get the teeth all equal in width and height.

Before you do your last pass, set the teeth. If you file from only one side of the saw, you will have a better chance of getting all the teeth the same. Don't put too much set in the teeth. All you want is enough so the blade won't bind in the kerf. Just barely bend the teeth. If the saw binds, you can always add a tad more. Over setting the teeth makes for a rough cutting saw.

After you set the teeth and file the last pass, side joint the teeth on both sides by lightly sliding a flat sharpening stone down the tooth line a couple times. This will remove the burr at the tips of the teeth and will make them all even.

Good luck:)