Saw jointing and teeth reshaping.. i’m frustradted

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  • #715861
    bow
    Participant

    God morning ( Italy here, 10.01 AM)

    I’m in doubt here and i feel myself a bit frustrated because i can sharpen a chisel, a plane iron to cut as razors but im not able to sharpen a saw to an high point of sharpness.
    First i remove the remaining set gently hammering the teeth. second i pass a flat file over the teeeth line till almost all the teeth have a “flat”. Third: i start to reshape and space the teeth: i direct the file more on the teeth wich have larger flats while i press the file less over the teeth wich have smaller flats, i do two file passes this way. While doing this, i observe teeth spacing and do the same thing, ialternatuing file pressure.
    Flats usually dont disappear yet at this stage, so i make another two file passes for every tooth…and again and again till the gflats are almost desappeared.
    Then i sharpen the saw with a pass or two : i use a fresh corner of the file and use lighter force over the file.
    Here my frustration begins. Ifeel some teeth cutting more than other, that probably are lower and they dont cut at all.. I look at teeth line and see gullets are not at the same depth, there is a little discrepancy. I dont know wahts the correct procedure is here….i lack of knowledge…..

    #715866
    Larry Geib
    Participant

    The first step in filing saw teeth is to use a flat file to ‘top’ all the teeth to the same height and there is a small flat on the top of each tooth. Then file the teeth until the flats disappear. That will assure even teeth.
    It’s not necessary to remove the set. If fact doing that can work harden the teeth and break them off.

    Paul has hours of video on WWC and on YouTube on the correct sharpening steps, all the way from freshening up a saw to an entire retooth job.

    A good one to start with is here:

    It’ s long. Have a snack and you favorite beverage handy.
    Write the steps down so you don’t forget any.

    The google “ Paul sellers saw sharpening “ and you’ll probably get a couple hours worth of video.
    Do the same with saw setting, too.

    Search in the wwmc and common woodworking sites, and probably the Paul sellers blog as well. He’s got lots of great stuff on saws.

    #715869
    Francois
    Participant

    Hi !
    The file is used to level the saw teeth. Then you have to file the entire saw tooth by tooth and repeat until there are no more flats. This way each tooth will be filed with the same number of strokes for each tooth.
    If you file more the teeth with larger flats they will be lower than the others with small flat.
    Also keep in mind that a tooth can be sharpened from the front and the back. If you focus on a tooth with a large flat from the front for example, it will be sharp but the front gullet will be deeper than the back one. So sharpening each tooth with the same number of strokes is, i think, the only way to keep everything level and consistant.

    I’m not an expert in saw sharpening but I think this could be the problem.

    EDIT : Paul Sellers seems to say in this video that you have only to insist on the ones with larger flats (but from each side), so maybe my contribution is not so relevant

    #715872
    Larry Geib
    Participant

    Right! You don’t count strokes, especially if the teeth are uneven. File until the flats are gone paying attention that you are shaping the teeth the same size.

    Sometimes the teeth are so uneven you have to file them completely off and start over. Paul has a video on that also.

    But I’ve found that if you go slowly, not cutting one tooth and then the next, but groups of teeth together paying attention to size and shape, you can go a long way to resurrecting a good profile after a couple sharpenings and the saw will cut well.

    You can ‘move’ a tooth a bit with filing pressure. I made a file with a “safe” side by rubbing one flat on a diamond plate that helps move a tooth. That moves a tooth a lot, but you can also easily go astray with it.

    • This reply was modified 5 months, 3 weeks ago by Larry Geib.
    #715873
    Colin Scowen
    Participant

    I find a magnifying glass and an aluminium straight edge help a lot in evaluating the teeth before, during and after sharpening. My saws were all old ones, so they had seen some wear and some sharpening before I got hold of them. Some teeth were higher than others, some gullets deeper than others. But the majority of my usage is about 3 – 5 cm of contact with the wood, so a bit of a curve is not too much of an issue. A longer contact area may make the curve more of an issue, and it may be this that makes you think some teeth are not cutting as well as others.
    It would be worth checking if the tips of all the teeth are at the same level, just so you have a better understanding of the state of the saw before you start filing them all down.

    Colin, Czech Rep.

    #715880
    bow
    Participant

    Many thanks : youre messages are great teaching to me . i saw all the video of Paul sharpenings saw. I’d like to discuss a pot Paul did some months ago about rehabbing a badly sharpened tenon saw. Teeth were in so bad shape i thought he would have filed out them and recut new ones; he simply reshaped with a triangular file and claimed it simple work done in half an hour:

    https://paulsellers.com/2019/09/filing-brutalised-saw-teeth/

    I’d gave up here. What did Paul?

    1) one file stroke and one only on each gullet. What is its meaning? i dont know.
    2)Look ate the gullets: if they are even it means saw is a good candidate to restore well
    3) jointing the teeth with 10″ flat file with fine cut.
    4)Reshaping-spacing teeth begins. Paul directs much pressure against the larger flats sayng that larger teeth have to be filed from the back gullet and from the front gullet , iat the contrary more uneveness will appear

    Four file-strokes for each gullets did the job.

    another golden trick is added on comments: he says that giant teeth are to be taken care before other teeths.. so no matter gullets depth . no matter file strokes count: what it really matteres are the flats on the teeeth ( to be filed accordingly to instrucions).
    Am i wrong?

    #715898
    Ed
    Participant

    I’d like to point out a question I asked Paul on that blog post:

    When dealing with tall teeth, would you estimate that you remove the flat equally from the top and front of the tooth? This post was an Aha! moment for me. Thank you! I’ve been jointing too heavily when fixing saws! I see now that, rather than going right for a nice flat profile and then dealing with sorting out how much to file each tooth, it may be much easier to take a moderate jointing pass, leaving some or even many teeth untouched, sort out the teeth that were hit, then repeat. This will naturally cause some teeth to be filed more as you repeat. That’ seems so much better than what I’ve been doing, which is to joint heavily and have various sized flats so that one must guess how much extra to give the wider ones vs. the medium and smaller flats. You remove a staggering amount of material in a single 2 1/2″ stroke based upon those two photos! That would have been half a dozen strokes for me. Maybe I need more hand pressure!

    Paul’s answer was:

    It is a question of gently, stealthily approaching the enemy in the land of the giants.They don’t mean to stand out. File off the tops of the highest ones and take down the big giants first; less to be overwhelmed by. File the tooth from both sides but remember too that you may want some to take off the adjacent tooth with a final stroke or two.

    Saw sharpening is the hardest sharpening activity for me. I’m still unhappy with my ability, but my saw is usable. I’ve used saws sharpened by Paul and, while mine are okay, they aren’t like his. With that caveat, here’s my suggestion: Don’t try to get to a perfect saw like Paul does. Ideally, we want sharp teeth, equally spaced, equally shaped. My suggestion is to focus on sharp teeth, even if they are not equally spaced and sized. Let some be imperfect. Over time, as you sharpen more, aim for getting more as you want it. In the interim, the saw will be useable, even if not as good as Paul’s. So, get what you have sharp (meaning no flats, but maybe teeth vary) and properly set for your work. Make a test cut and ensure that it cuts straight. Even if the teeth are somewhat wonky, let it be and get to work. Resharpen often. You will gain confidence from this. For me, the key thing is that many of the teeth are sharp and level, even if not all, that I have the right amount of aggressiveness for the teeth, that the set is as small as I dare for the work and that I get a clean cut, not a jagged one. Trust me, you can achieve that even with imperfectly spaced teeth.

    You don’t need a perfect saw to get a good or even perfect cut. An imperfect saw can give an excellent cut, but just be a little inefficient. For me, there is a threshold effect. I must get to the point of the saw not skating on my layout line (a matter of jointing and having enough jointed teeth sharp plus a little bit of being aggressive enough shape), and it should cut straight. That one is almost a must, but I’ve faked it in a pinch. Once you can get those, cutting without making a jagged kerf becomes important and, as your skill builds, becomes a must. I’ve achieved all of those on a saw that had imperfect teeth sizes and wasn’t perfectly efficient. If this paragraph is confusing, imagine a tenon saw that is convex or, worse, wavy in tooth height. It will want to skate. By contrast, if I joint it so that it is mostly flat but random teeth are low, I can get into the work without skating, but the random teeth won’t help cut, so the efficiency is a little less. This can be made good enough to get to work.

    Please, please tell me you are practicing with a rip, not a crosscut. 🙂

    I have seen so many cows and calves in the wild, and have seen them so uniform, that I honestly wonder if it was done deliberately for reasons that we collectively no longer remember.

    • This reply was modified 5 months, 3 weeks ago by Ed.
    • This reply was modified 5 months, 3 weeks ago by Ed.
    #715901
    Ed
    Participant

    I better say what I mean by, “skate.” When I cut, I somewhat unweight the saw and gently rub at the far side of my layout line until I’ve gotten a couple teeth exactly where I want them next to the line _and_ I’ve established my arm motion. At this point, I drop the heel of the saw. Especially on wider cuts, when I drop the heel of he saw to make contact with the layout line (especially longer ones), I want the saw to immediately enter the wood along its length. I don’t want it to take two or three passes dropping the heel more as I go or waiting for the saw to enter the line and I don’t want dropping the heel to cause the nose to jump and chatter out of the cut. Failing in this way is what I mean by skating. Saws that are reasonably called sharp (at the tooth level) can do this (bad) thing. For me, this is the Holy Grail of sharpening. One of Paul’s class saws did this better than any of his others and he sharpened all of them, so it is a bit elusive. I coveted that saw.

    #715996
    bow
    Participant

    I’d like to point out a question I asked Paul on that blog post:

    When dealing with tall teeth, would you estimate that you remove the flat equally from the top and front of the tooth? This post was an Aha! moment for me. Thank you! I’ve been jointing too heavily when fixing saws! I see now that, rather than going right for a nice flat profile and then dealing with sorting out how much to file each tooth, it may be much easier to take a moderate jointing pass, leaving some or even many teeth untouched, sort out the teeth that were hit, then repeat. This will naturally cause some teeth to be filed more as you repeat. That’ seems so much better than what I’ve been doing, which is to joint heavily and have various sized flats so that one must guess how much extra to give the wider ones vs. the medium and smaller flats. You remove a staggering amount of material in a single 2 1/2″ stroke based upon those two photos! That would have been half a dozen strokes for me. Maybe I need more hand pressure!

    Paul’s answer was:

    It is a question of gently, stealthily approaching the enemy in the land of the giants.They don’t mean to stand out. File off the tops of the highest ones and take down the big giants first; less to be overwhelmed by. File the tooth from both sides but remember too that you may want some to take off the adjacent tooth with a final stroke or two.

    Saw sharpening is the hardest sharpening activity for me. I’m still unhappy with my ability, but my saw is usable. I’ve used saws sharpened by Paul and, while mine are okay, they aren’t like his. With that caveat, here’s my suggestion: Don’t try to get to a perfect saw like Paul does. Ideally, we want sharp teeth, equally spaced, equally shaped. My suggestion is to focus on sharp teeth, even if they are not equally spaced and sized. Let some be imperfect. Over time, as you sharpen more, aim for getting more as you want it. In the interim, the saw will be useable, even if not as good as Paul’s. So, get what you have sharp (meaning no flats, but maybe teeth vary) and properly set for your work. Make a test cut and ensure that it cuts straight. Even if the teeth are somewhat wonky, let it be and get to work. Resharpen often. You will gain confidence from this. For me, the key thing is that many of the teeth are sharp and level, even if not all, that I have the right amount of aggressiveness for the teeth, that the set is as small as I dare for the work and that I get a clean cut, not a jagged one. Trust me, you can achieve that even with imperfectly spaced teeth.

    You don’t need a perfect saw to get a good or even perfect cut. An imperfect saw can give an excellent cut, but just be a little inefficient. For me, there is a threshold effect. I must get to the point of the saw not skating on my layout line (a matter of jointing and having enough jointed teeth sharp plus a little bit of being aggressive enough shape), and it should cut straight. That one is almost a must, but I’ve faked it in a pinch. Once you can get those, cutting without making a jagged kerf becomes important and, as your skill builds, becomes a must. I’ve achieved all of those on a saw that had imperfect teeth sizes and wasn’t perfectly efficient. If this paragraph is confusing, imagine a tenon saw that is convex or, worse, wavy in tooth height. It will want to skate. By contrast, if I joint it so that it is mostly flat but random teeth are low, I can get into the work without skating, but the random teeth won’t help cut, so the efficiency is a little less. This can be made good enough to get to work.

    Please, please tell me you are practicing with a rip, not a crosscut. 🙂

    I have seen so many cows and calves in the wild, and have seen them so uniform, that I honestly wonder if it was done deliberately for reasons that we collectively no longer remember.

    • This reply was modified 5 months, 3 weeks ago by Ed.
    • This reply was modified 5 months, 3 weeks ago by Ed.

    I better say what I mean by, “skate.” When I cut, I somewhat unweight the saw and gently rub at the far side of my layout line until I’ve gotten a couple teeth exactly where I want them next to the line _and_ I’ve established my arm motion. At this point, I drop the heel of the saw. Especially on wider cuts, when I drop the heel of he saw to make contact with the layout line (especially longer ones), I want the saw to immediately enter the wood along its length. I don’t want it to take two or three passes dropping the heel more as I go or waiting for the saw to enter the line and I don’t want dropping the heel to cause the nose to jump and chatter out of the cut. Failing in this way is what I mean by skating. Saws that are reasonably called sharp (at the tooth level) can do this (bad) thing. For me, this is the Holy Grail of sharpening. One of Paul’s class saws did this better than any of his others and he sharpened all of them, so it is a bit elusive. I coveted that saw.

    I’m restoring a small Bahco gent saw with 13 tpi. it had an hybrid cut teeth taht performed equally bad ripcut and crosscut wise. I reshaped all the teeth in rip configuration and added 12° rake. Nothing more than this.

    A saw taht starts as you described makes easier to perform a plumb and straight cut . a pleasure to use. I got your meaning: we have good cutting saws withouth too much effort on perfection !

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