Crosscut Saw cutting slow - sharpening advice

[tibi]

Hello,

I have bought a 26" 7 ppi crosscut saw and I have sharpened it. I have watched multiple videos on sharpening both rip and crosscut saws (Paul Sellers, Frank Strazza, Wood By Wright, etc.)
I have used around 10° of rake and 12,5° of fleam. I will cut mostly hardwoods. The saw has a relatively thin kerf and it cuts straight. The saw was first jointed to level, because there was a 2,5 cm hollow in the middle, so I had to joint and sharpen multiple times not to lose the tooth pattern completely. I have taken care to have almost all teeth at the same height.

When I compare my saw to this Badaxe 8ppi, I have cut a similarly thick board of dry oak and my sawing speed was 4-5x slower when taking full strokes. When cutting silver fir, it was also slow.


The saws that I have sharpened rip cut relatively fast.

What are some good tips to make the crosscut saw cut faster? The finish quality is not that relevant, because I will always use the shooting board to make everything square and clean.

I do not have an option to send the saw to someone who actually knows how to sharpen it, unless I want to send it to the USA, that would make it too expensive. When I started woodworking, I took my all plane blades and gave them to a local professional sharpening specialist who sharpens table saw blades, drill bits, etc. and all he did was he used a machine to sharpen them at the required angle. I do not need to say that they were not sharp enough from the grinding wheel. In my country I have not heard of anyone still using hand saws, so the sharpenings skills might be also gone.

Thank you for your tips.

 

[D_W]

sharpen it rip with a 10 degree rake first and then see how fast it cuts in something 8/4. That should give you a good starting point - you have relatively little fleam on the saw, so it should cut almost as fast as it would set rip.

Aside from tooth geometry, two things can go awry sharpening saws - too much rake and fleam leading to rasping instead of cutting (that shouldn't be the case with your numbers) and something awry at the tooth tip - something not sharp). The saw should pretty much pull itself into the cut and be just a bit sticky the first few cuts after you sharpen.

 

[tibi]

sharpen it rip with a 10 degree rake first and then see how fast it cuts in something 8/4. That should give you a good starting point - you have relatively little fleam on the saw, so it should cut almost as fast as it would set rip.

Aside from tooth geometry, two things can go awry sharpening saws - too much rake and fleam leading to rasping instead of cutting (that shouldn't be the case with your numbers) and something awry at the tooth tip - something not sharp). The saw should pretty much pull itself into the cut and be just a bit sticky the first few cuts after you sharpen.

Thank you very much D_W,

The problem might be that there could be some teeth where the front and back of the tooth do not meet at a single point ( there could be a little flat spot). I will check the saw tomorrow.

What is a bigger issue in speed? Not to have all the teeth sharpened to a sharp point or not having an equal height of the tooth, i.e. to have all the teeth at the same level. This way only some of the teeth will actually cut. It is tricky to achieve perfectly both.

 

[D_W]

The flat top on a tooth is toxic. I'm not meaning to exaggerate it, but it has no way of biting in no matter what. It can't dig in to sever fibers forward like a rip tooth, nor can it sever fibers at the side like a crosscut tooth - it will skid and as long as its in the cut, so too will the teeth around it.

If you only successfully do two things sharpening, you want:
1) no flats on teeth
2) teeth to be the same height

Everything else is behind that. The first will make teeth cut fast, the second will make them cut smoothly. unsharpened flats can be tricky to see on a crosscut saw or a rip saw as they get small. Take a saw out of the vise when you sharpen it and turn slowly in a 360 circle moving the saw around - under intense light, it can be hard to see small flats, but against some varying light, you can see them. Of course you can also mark the teeth on the tips with a good marker or with marking fluid when sharpening. Once you have those flats off, it's a one and done thing - you want to sharpen like a robot after that - which will achieve 1 and 2 over and over (no jointing, no flats).

you will get to the point that you build a rhythm with the file that you don't break and concentrate on staying in that rhythm and making each stroke feel identical (which will lead toward metal removal being close to identical).

 

[IWW]

Tibi, in my view you have not put enough rake or enough fleam on those teeth for a crosscut saw. The generally-advised starting point is 15 degrees of rake and 15-20 degrees of fleam. The amount of rake is far less critical on crosscut teeth compared with rip teeth, where a change of just a few degrees will make a noticeable difference. You have to change rake angles by about 5 degrees at least to notice a difference with crosscut teeth, but 5 more degrees of fleam should make a bigger difference. That's because of the completely different action of the teeth in each case. Rip teeth are ofen referred to as having "chisel points" but I think "scrapers" is a far more apt comparison, while crosscut teeth act like a series of vertical knives. The rake angle in their case gives a slicing action equivalent to slewing a plane, while the fleam gives the teeth their "knife" edges.

Theoretically, therefore, the more acute the fleam angle, the sharper the knife, and the more laid-back the rake, the more slicing action you get as they are dragged across the fibres. As with everything in life, there has to be compromises, and years of experience have shown that the angles mentioned work well enough across a broad range of conditions. When you are more familiar with saws & sawing you can play with tooth configuration & figure out what works best for you. Fleam angles can be as extreme as 45 degrees for certain applications (like on the tapered, "no-set" saws), but I think it's wise to begin at a good median start-point.

My advice would be to first increase your fleam angle to 15* and see if it makes a difference. That is a relatively easy "correction" to make, it should take no more than 2 strokes per tooth, followed by a very light "clean-up" stroke, if your file is sharp. I suspect it will make a big difference to your speed of cutting. The next time you sharpen, try & increase the rake by applying a little more pressure to the leading side of each tooth as you go. This is a more tricky correction for a novice; as it is, you probably struggle to keep even pressure on leading & trailing edges as you file when you switch sides, which results in alternately smaller & larger teeth. This was my greatest difficulty in sharpening crosscut teeth when I started, and I still have to concentrate on that aspect to get them even. With ripsaws, you can file all of the teeth from one side, & although most old texts say you should do alternate teeth from opposite sides, as a beginner you'll likely get much better results doing them from one side only, as long as you keep the file square & perpendicular to the blade. Small rip teeth are far easier to keep even if filed from one side only.

I would not advise converting the teeth to rip profile, unless you really need a ripsaw. For sure, it's much easier for a novice to do a decent sharpening job on rip teeth, and a well-sharpened ripsaw can cross-cut almost as fast, if not as fast, as a well-sharpened crosscut. For saws of around 15tpi & higher, the difference between speed & quality of cut is too small for most people to worry about. However, for larger tooth sizes crosscutting hardwoods with teeth optimised for ripping is not a pleasant exercise. The action is rougher and more fatiguing, the cut surface is rougher, & the tear-out may be intolerable. A well-sharpened crosscut usually cuts noticeably faster & more smoothly in dry, hard woods and is far more pleasant to use.

Rome wasn't built in a day, and learning to sharpen saws well is not something you will achieve in one easy lesson! But if you are fully aware of what you are trying to do, & persist, the skill will come; stick at it!

Ian

 

[IWW]

David, I agree in principal with what you say - a steady rhythm, constant file angle & even pressure is what it's all about and a skilled sharpener does not need to joint well-maintained teeth as a rule. Most people nowadays don't use files much so they have to acquire a feel for efficient filing as well as develop the fine motor coordination necessary to produce consistent angles & gullets. I've coached a few would-be saw sharpeners & like any skill, some learn quickly, others struggle to make any headway. And because of the small number of saws sharpened at erratic intervals, most amateurs are never going to be brilliant at it, but most can at least learn to do an acceptable job.

With practice, the process becomes more & more easy & intuitive, but a novice will not have that touch, and needs all the help they can get. Imo, regular light jointing every couple of sharpenings is something that can help. It removes a negligible amount of metal, but makes it much easier to see any teeth that need more attention. If the saw hasn't been sharpened for a while, the shiny flats stand out very clearly against the dull gullets, but if you've had to re-form very irregular teeth, which often involves re-jointing during the process, of course everything will be shiny & they won't stand out nearly as well. A good light positioned at the right height & the right angle can make the flats much easier to see clearly, as does a head loupe (mandatory, for my aged eyes for anything finer than about 2tpi!).

Anyway, regular light jointing as a way of keeping teeth even is my recommendation to all occasional saw-sharpeners...
Cheers,
Ian

 

[tibi]

Tibi, in my view you have not put enough rake or enough fleam on those teeth for a crosscut saw. The generally-advised starting point is 15 degrees of rake and 15-20 degrees of fleam. The amount of rake is far less critical on crosscut teeth compared with rip teeth, where a change of just a few degrees will make a noticeable difference. You have to change rake angles by about 5 degrees at least to notice a difference with crosscut teeth, but 5 more degrees of fleam should make a bigger difference. That's because of the completely different action of the teeth in each case. Rip teeth are ofen referred to as having "chisel points" but I think "scrapers" is a far more apt comparison, while crosscut teeth act like a series of vertical knives. The rake angle in their case gives a slicing action equivalent to slewing a plane, while the fleam gives the teeth their "knife" edges.

Theoretically, therefore, the more acute the fleam angle, the sharper the knife, and the more laid-back the rake, the more slicing action you get as they are dragged across the fibres. As with everything in life, there has to be compromises, and years of experience have shown that the angles mentioned work well enough across a broad range of conditions. When you are more familiar with saws & sawing you can play with tooth configuration & figure out what works best for you. Fleam angles can be as extreme as 45 degrees for certain applications (like on the tapered, "no-set" saws), but I think it's wise to begin at a good median start-point.

My advice would be to first increase your fleam angle to 15* and see if it makes a difference. That is a relatively easy "correction" to make, it should take no more than 2 strokes per tooth, followed by a very light "clean-up" stroke, if your file is sharp. I suspect it will make a big difference to your speed of cutting. The next time you sharpen, try & increase the rake by applying a little more pressure to the leading side of each tooth as you go. This is a more tricky correction for a novice; as it is, you probably struggle to keep even pressure on leading & trailing edges as you file when you switch sides, which results in alternately smaller & larger teeth. This was my greatest difficulty in sharpening crosscut teeth when I started, and I still have to concentrate on that aspect to get them even. With ripsaws, you can file all of the teeth from one side, & although most old texts say you should do alternate teeth from opposite sides, as a beginner you'll likely get much better results doing them from one side only, as long as you keep the file square & perpendicular to the blade. Small rip teeth are far easier to keep even if filed from one side only.

I would not advise converting the teeth to rip profile, unless you really need a ripsaw. For sure, it's much easier for a novice to do a decent sharpening job on rip teeth, and a well-sharpened ripsaw can cross-cut almost as fast, if not as fast, as a well-sharpened crosscut. For saws of around 15tpi & higher, the difference between speed & quality of cut is too small for most people to worry about. However, for larger tooth sizes crosscutting hardwoods with teeth optimised for ripping is not a pleasant exercise. The action is rougher and more fatiguing, the cut surface is rougher, & the tear-out may be intolerable. A well-sharpened crosscut usually cuts noticeably faster & more smoothly in dry, hard woods and is far more pleasant to use.

Rome wasn't built in a day, and learning to sharpen saws well is not something you will achieve in one easy lesson! But if you are fully aware of what you are trying to do, & persist, the skill will come; stick at it!

Ian

Thank you Ian for your response. I always thought that less rake and fleam = more aggressive cutting, thus faster speed and less clean cut. I did not think that having more fleam can make my cutting faster. So my next configuration will be 15° of rake and 15 ° of fleam. I will try to maintain both a sharp point and equal height of all teeth. I will make this jig for sharpening with the wooden body with two tapered sides with the angle of fleam angle and a hole where a side of the triangle will be colinear with 15°rake angle. This is the standard DYI version of the sharpening jig for crosscut saws. I would improve it a bit by attaching two steel angles to the sides, so when I start filing the angle will touch the saw plate and I will get the tapered side exactly 90 degrees perpendicular to the saw plate and subsequently getting the exact fleam angle that I want. I could then make those jigs for every filing configuration and file size that I need.

 

[deema]

If I heard correctly on the video, the Bad Axe saw is cutting maple not seasoned oak. Maple is far easier and faster to cut.
I don’t believe there is any issue with the fleam or rake you have, anything varying away from RIP just makes sawing slower. If it’s cutting slower the main issue is that you haven’t got the teeth ‘sticky’ sharp. If the saw teeth when laid on your hand and then pulled away don’t seem to stick to your hand it isn’t sharp enough. Difficult to describe, but once you’ve experienced it you know what ‘sticky sharp’ feels like.

 

[D_W]

your oak may be different than ours. red and white oak here isn't a big deal to cut compared to hard maple. I don't know if they're equal, and maybe the oak feels more stringy, but it rips easily and isn't that bad to crosscut.

 

[IWW]

Have I misunderstood? Tibi, are you wanting a rip saw or a crosscut saw? I had the impression you wanted a crosscut, so my advice was aimed at achieving an efficient crosscutting tooth profile.

Your proposed guide is way more elaborate than necessary & not very practical, imo. It's better to have a narrow guide because the saw should sit as low in the vise as you can get it to prevent the blade from flexing as you file, and a thick thing like you show will foul on the vise. A stick about 6-8mm square (depending on the size of file you are using) and 75-80mm long is adequate (the longer the stick, the easier it is to see if it's square & parallel to the vise, but over 80mm gets a bit awkward for me). This takes about 30 seconds to make, just mark the desired angle(s) on the sick, drill a small hole beside it & jam the file in with one side matching your line:

This one is for a ripsaw, so the stick is perpendicular to the file. For a crosscut, drill the hole at the fleam angle. It doesn't have to be clockwork precise, a degree or even two either way won't matter. You don't need to start the file with the guide touching the saw, you'll soon get the hang of holding it close enough to check at a glance that it's parallel before starting the stroke. What is most important is consistency.

I have a Veritas filing guide, which is quite good, as you can just dial in whatever rake & fleam angles you need, but it's an unnecessary expense for an occasional filer and as often as not I can't be bothered fiddling with it & just grab a stick I've used before when re-forming teeth or cutting new ones. The stick is actually easier to hold straight than the small finger knob on the Veritas, which makes my fingers cramp when doing a lot of teeth. The hole in the stick will get a bit loose after a few uses; just toss it in the fire & make a new one.

You won't need a guide for light re-sharpening, once you have good gullets they become your guide....

Cheers,
Ian

 

[tibi]

Have I misunderstood? Tibi, are you wanting a rip saw or a crosscut saw? I had the impression you wanted a crosscut, so my advice was aimed at achieving an efficient crosscutting tooth profile.

Your proposed guide is way more elaborate than necessary & not very practical, imo. It's better to have a narrow guide because the saw should sit as low in the vise as you can get it to prevent the blade from flexing as you file, and a thick thing like you show will foul on the vise. A stick about 6-8mm square (depending on the size of file you are using) and 75-80mm long is adequate (the longer the stick, the easier it is to see if it's square & parallel to the vise, but over 80mm gets a bit awkward for me). This takes about 30 seconds to make, just mark the desired angle(s) on the sick, drill a small hole beside it & jam the file in with one side matching your line: View attachment 107076

This one is for a ripsaw, so the stick is perpendicular to the file. For a crosscut, drill the hole at the fleam angle. It doesn't have to be clockwork precise, a degree or even two either way won't matter. You don't need to start the file with the guide touching the saw, you'll soon get the hang of holding it close enough to check at a glance that it's parallel before starting the stroke. What is most important is consistency.

I have a Veritas filing guide, which is quite good, as you can just dial in whatever rake & fleam angles you need, but it's an unnecessary expense for an occasional filer and as often as not I can't be bothered fiddling with it & just grab a stick I've used before when re-forming teeth or cutting new ones. The stick is actually easier to hold straight than the small finger knob on the Veritas, which makes my fingers cramp when doing a lot of teeth. The hole in the stick will get a bit loose after a few uses; just toss it in the fire & make a new one.

You won't need a guide for light re-sharpening, once you have good gullets they become your guide....

Cheers,
Ian

Ian, I want to have a more aggresive crosscut saw for initial trimming rough material, not for final work. Thank you for the stick guide, I will make one today and try it out.

 

[tibi]

The mystery is now resolved. I had a substantial amount of teeth where little triangular flat spots were on the top of the tooth. I will try to sharpen them in a way that a sharp point will be made on every tooth and try to make all the teeth level at the same time.

 

[Jacob]

No mystery! It is what is known as a "blunt" saw. Very blunt in your case!
Might help if you run a black marker felt tip along the edge before you sharpen - when the black is all gone so have the flats. And it's easier to see where you have been with the file.

 

[pe2dave]

From the photographs, it would seem your file isn't steep enough? Apart from not finishing each tooth,
that lesser angle will reduce cutting angle.
Paul, about 6 minutes in?

 

[tibi]

No mystery! It is what is known as a"blunt" saw. Very blunt in your case!
Might help if you run a black marker felt tip along the edge before you sharpen - when the black is all gone so have the flats. And it's easier to see where you have been with the file.

I was afraid to proceed with further sharpening because when I sharpen each tooth to a point, some teeth requires more strokes to remove the flat and some less - thus making them of unequal height. I can sharpen partially from one side and partially from other side, so I will not remove the flat by sharpening from one side only. But it requires skill to know how much to sharpen from one side and from the other so that the tooth maintains the consistent height.

 

[Jacob]

I was afraid to proceed with further sharpening because when I sharpen each tooth to a point, some teeth requires more strokes to remove the flat and some less - thus making them of unequal height. I can sharpen partially from one side and partially from other side, so I will not remove the flat by sharpening from one side only. But it requires skill to know how much to sharpen from one side and from the other so that the tooth maintains the consistent height.

You file half of each flat from one side, working up the saws whole length from one side, then the other half from working from the other side.
The flats are the same height. When the flats have just disappeared and become points, then the points are the same height.
But a bit of variation doesn't matter too much. It's much more important to have sharp points rather than a dead straight edge.
You may also need to set the teeth but try it first, you don't always need to set every time you sharpen.
PS a neat description here of tooth geometry. Blackburn Tools - saw tooth geometry See figure 4.
Maybe you also need more slope with your file? See this link:http://www.blackburntools.com/articles/saw-tooth-geometry/index.html#point-slopePS I'd avoid all guides and jigs, they just add another element to have to pay attention to. Just look at the file and keep it at same angle

 

[tibi]

You file half of each flat from one side, working up the saws whole length from one side, then the other half from working from the other side.
The flats are the same height. When the flats have just disappeared and become points, then the points are the same height.
But a bit of variation doesn't matter too much. It's much more important to have sharp points rather than a dead straight edge.
You may also need to set the teeth but try it first, you don't always need to set every time you sharpen.
PS a neat description here of tooth geometry. Blackburn Tools - saw tooth geometry See figure 4.
Maybe you also need more slope with your file? See this link:http://www.blackburntools.com/articles/saw-tooth-geometry/index.html#point-slopePS I'd avoid all guides and jigs, they just add another element to have to pay attention to. Just look at the file and keep it at same angle

Thank you very much Jacob for precious advice. I have already set the teeth, because I needed to file at least 2 cm in incremental steps, to remove the hollow in the middle of the saw, so not much set was left. The kerf was too thick, so I used a hammer and anvil and evened it out. Now it is much better.

So I will resharpen the saw according to your instructions and instructions of others ( a mix of it

 

[Jacob]

Thank you very much Jacob for precious advice. I have already set the teeth, because I needed to file at least 2 cm in incremental steps, to remove the hollow in the middle of the saw, so not much set was left. The kerf was too thick, so I used a hammer and anvil and evened it out. Now it is much better.

The 2cm hollow sounds mysterious! I think I would have left in - it would not have made much difference to your sawing

So I will resharpen the saw according to your instructions and instructions of others ( a mix of it

Take your pick! The felt tip marker is a good tip though.
There can be a big difference between making a saw perfectly usable and/or restoring it to near manufacturers spec.

 

[tibi]

I have sharpened the saw again and the difference is remarkable

 

[Jacob]

I forgot to add - the simplest way to sharpen a saw (if it was OK before it needed it) is to pick up the angles already used by laying you file into the gullet until it's a close fit, then carry on filing at that angle. Work alternate gullets one side, turn and do the other side. You get a feel for it - best if you work from end to end without stopping so that you don't change the angle, nor file the same gullet twice. A missing tooth or two - just carry on as if they were still there, pressing down into the gullet. After a few sharpenings the tooth will have reappeared.
Don't set it until you have tried it - it might not be needed.
Much easier than trying to impose your own chosen angle or other radical saw doctoring