Who cuts new saw teeth?

[Jim Paulson]

Hi Guys,

I confess I'm less of a machinist than some of you so maybe you'll not mind if I ask this: what would be a good approach to get new teeth cut on an old saw? I have an old backsaw that is crosscut and I'd like to change it to a rip. I am also less concerned with some of the nuances of blade thickness although I love the performance of my LN dovetail saw.
Should I send to someone who does that or should I try to file new teeth? Who does that? I'd be a complete novice on filing new teeth, but filing a 10 tpi rip seems a bit of a challenge. I'd be happier trying to file teeth on a panel saw, but I haven't done that yet either.

Jim

[Robert Rozaieski]

Jim,

If all you want to do is change from crosscut to rip, you don't need to have new teeth cut in. In fact, your 10 point saw would be the perfect saw to learn this on. The teeth are not too small and not so big that you will have to file a lot of metal off. I suggest trying it yourself. The worst that will happen is that you screw it up and THEN have to send it out. But really, try it out yourself before immediately sending it to someone else. Rip teeth are a piece of cake to file. And if you aren't changing the number of teeth or the rake angle it's even easier. Here's a brief description of how I would do this.

First, get yourself a saw file. For a 10 point saw you can use a 6" extra-slim, a 6" double-extra slim or a 5" extra slim all successfully. These are available for a couple of bucks from a lot of places. Home Depot even carries the 6" extra-slim I believe. You will also want a mil-file for jointing. Anything from a 6" to a 12" flat mill file will work. Forget a saw set for now. The saw you have likely has too much set as it is so filing the teeth will likely remove just the right mount to make the set right.

Next, get three scraps of wood. Two should be flat and at least as long as your saw plate. These will be your make-do saw vise. The third piece of wood should be square on two adjacent sides. This will be used with your mil file to make sure you joint your saw teeth square.

Now, take a bevel gauge and gauge your saw's rake angle. This is the angle that the front of the saw tooth makes with the bottom of the saw plate. Just get close. It doesn't need to be perfect. This is the angle you want to file at. Don't worry about what the exact angle is now, just use whatever angle you gauge from the the saw with your bevel to make a rake angle alignment block for your file following Pete Taran's directions here (half way down the page look for "Making a Rake Alignment Jig):
http://www.vintagesaws.com/library/primer/sharp.html
If you really want to change the rake angle, feel free to do so but you may need to joint the teeth a little lower and file a little more to do so. No big deal but not neccessary for your first go round.

Now you are ready to get started. First you need to joint the teeth so they are all the same height. place one stick of your make-do saw vise on either side of the saw plate and clamp the whole thing in your bench vise with as much of the blade above the bench top as you can get. Now hold the mil file on top of the third piece of wood and using the wood as a fence to hold the file flat, file the tips of the teeth from the heel of the saw to the toe. Just make enough smooth strokes to get a small flat spot on the top of each tooth. This will make all the teeth the same height. It should only take two or three strokes with the mil file if your teeth are not that bad to begin with.

Now, reset your make-do saw vise so only a very little of the blade sticks up above the vise. You want the teeth to be as close to the vise as they can be and still have access to file them. This will reduce vibration as you file across the the saw plate. Place your file in the rake alignment block as instructed in Pete's directions. Make sure the arrow points at the handle so you get the rake angle right.

You now want to file the front side of all the teeth that are leaning away from you. Start at the toe and work towards the handle filing every other tooth straight across (i.e. zero fleam). Don't worry about getting this perfect. A little bit of fleam from hand filing makes the saw cut smoother so it's perfectly ok. When you file, concentrate on putting the file into the corner of the gullet and keeping your rake alignment jig level. Go slow and file only the fronts of the teeth that are set away from you until the flat spot from jointing almost dissappears...ALMOST but not completely.

Now turn the saw around in the vise to prepare for filing the teeth you skipped. Remember to flip your rake alignment gauge as well so the handle arrow is pointing in the other direction. Now file the fronts of the teeth that you skipped before, which will be the ones that are set away from you (they were set toward you before you turned the saw around ). File just until the flats on the tips disappear and no further. This will also take care of the tiny bit of flat left on the teeth you filed the first pass since you are filing the back of those teeth now.

Finally, take the saw out of the vise and make one very light pass with a fine honing stone on each side of the saw plate from heel to toe to remove the filing burrs.

Now make a cut with your saw and be proud that you did it yourself . It is actually harder to write about it than it is to do it. And it's not a big deal if you screw it up a little. If it cuts ok you're good. If it needs more work, you can simply rejoint the teeth and try again. If the saw needs more set, you can get an inexpensive saw set and add just a little but it likely won't need it right away.

Try it, really! It's really very easy to do. Make it your new skill learned for 2009 !

[Jim Koepke]

Robert is right.

My first saw was done without any instructions. It was a tree saw. The improvement was so good, that I figured I should learn how to really sharpen a saw.

I am now getting to the point after just a few sharpenings that my next saw project is likely to be making new teeth on a saw that has none.

Read the instructions that Robert linked and you will be well armed for the task.

Good sawing,

jim

[Jim Paulson]

Thanks Robert and Jim for your encouragement. I should have given more information I guess especially with the thoroughness that Robert produced in his comment. I gather you both might suggest now that if want a rip saw it might be advantageous to make it a 12 or 13 point rip for now. I have two candidate saws that are Disstons, one 12" with 12 tpi and another at 14 inches with 13 tpi. That might be what I do and I'll certainly follow your advice. Eventually, I am hoping to have a 10 point rip to use as a tenon saw. LN and others have nice ones, but the practical side needs to be there for me these days.

Jim

[Alan DuBoff]

10 ppi is pretty course for a tenon saw. I would suggest 12 ppi, but all of our mileage varies.

I use a Foley to stamp teeth, but the method Robert links to and describes above works fine.

Your 12" with 12ppi sounds like a good saw to use for that. My $0.02.

[Robert Rozaieski]

Jim,

Keeping the TPI you have now is the best way to learn to sharpen. However, once you've done it once or twice, cutting in completely new teeth is not hard to do with a file. I will say that you will likely grow tired of the slow cutting of a 14 PPI (13 TPI) tenon saw after some use. My current tenon saw is 14 PPI (13 TPI) and I don't like the slow cutting. It's fine in narrow tenons but clogs badly in wider tenons. I'm currently making a new tenon saw that will be pitched at about 11-12 PPI (10-11 TPI).

To cut in new teeth you would first obviously need to file off all the existing teeth using the mil file. Then you need to mark the spacing for the new teeth and file them in. There are two ways I have used to do this.

With the first method, you print out a template. You can use a CAD program or other drawing program to draw a bunch of lines all spaced for your particular tooth spacing. For a 10 PPI (9 TPI) saw you want the spacing to be...wait for it...1/10th of an inch. For an 11 PPI (10 TPI) saw, the spacing is 1/11th of an inch. Pretty simple right. Next you use this template, clamped into your saw vise with your saw, to guide your file. Just place the corner of the file on the line and file in a new tooth. Just go a little bit until you have all the teeth marked but not completely shaped. Then go back and file away the flats like you would sharpen. You may need to make several passes just taking a few swipes on each tooth each pass and gradually sneak up on the final tooth shape to avoid filing too deep and changing the tooth spacing.

The beauty of this though is that you can cut all the teeth from one side of the saw without having to turn it around since there is no set yet. Once you have the teeth cut, following the sharpening instructions, starting with the jointing, but this time, after you joint the teeth, set them before you file them. Pretty simple.

The other way to mark the position of the new teeth is to clamp a hacksaw blade with the same PPI that you want for your saw along side your blank saw plate and use it as a template to establish the spacing. I like the lines better myself as I feel like the slightly irregular spacing that comes from freehand (kind of) filing the teeth into the saw plate make it chatter less in use, however, this may just be me.

Good luck with your filing. Be sure to post your results.

[Bill Hays]

Filing saw teeth is no doubt fun, but not as much fun as working with wood for me. I send my saws out on the rare occasion they need sharpening. The precision of mechanical filing seems to pay off in the accuracy of the cut.

If you are going to file though, think about getting a saw vise and set. They are common at tool auctions and cost very little; not much in demand I guess. Any general sharpening shop ought to sharpen saws, at least the common tooth sizes. The last time I had it done it was just a few dollars per saw.

Bill

[Matt Edwards]

Its true that saw sharpening isn't for everyone. It requires lots of patience in developing the the skill to do it effectively. IMO its a skill worth learning. Granted, I have no desire to sit in my shop joint and sharpen panel saws by hand all day. But, there are times that I enjoy the break from working with tools and enjoy working on them.

There is a pretty fair amount of satisfaction when the patience and practice yields a saw that performs better than any other in the till. I would recommend starting simple as Robert suggested, no need to run out and break the bank. Changing from cross cut to rip is pretty minor, and will go a long way in the practice it will give you. Actually, if you can joint and sharpen a saw, you can cut new teeth. Cutting teeth by hand is more layout, touch and repetition than super skill.

I'm not at all an expert, but I do maintain my saws, and I have made several of my joinery saws and re toothed the other joinery saws that I referbed.

Regards!
Matt

[Jim Paulson]

Hi,

I am still thinking about Robert's comments on sharpening. I love his idea of using a hacksaw blade as a guide to cutting new teeth. That would be more my style. Who knows maybe 2009 is the year to learn about refurbishing saw blades. I have a saw vise and set thanks to a relative, but I confess that I haven't put them much to use. This forum is great for motivating another person to try something.

I am also thinking that this gives me the excuse to pick up a couple old saws for learning sake.

God bless all of you,
Jim

[Jim Paulson]

Hello again,

Last night was our mall trip and the reason I was delayed in responding.
Hope you have warmer temps than us here. Our outside temp this morning is 1 degree Farenheit.

Jim

[Alan DuBoff]

I have a saw vise and set thanks to a relative, but I confess that I haven't put them much to use. This forum is great for motivating another person to try something.

Your half way there, get a file and your ready to give it a whirl. If you have any questions, ask.

[John Schreiber]

. . . I love his idea of using a hacksaw blade as a guide to cutting new teeth. . . .

Has anyone tried to use threaded rod as a guide? It was just an idea I had.

[Jim Koepke]

Has anyone tried to use threaded rod as a guide? It was just an idea I had.

I think any thing with a regular spacing has likely been used at one time or another.

Alan posted a link to a site that has patterns you can print for spacing, but for some reason it is now telling me I am not authorized to access the page. May be late night site administration.

If it continues to keep me out, I will have to make my own with computer and printer.

jim

[Alan DuBoff]

Alan posted a link to a site that has patterns you can print for spacing, but for some reason it is now telling me I am not authorized to access the page. May be late night site administration.

I sent Leif an email, he must have changed something and blammo! It happens...:-) I'm not sure what the direct links were to the ppi charts, they're PDFs I think.

I'll look and see if I can find them on my computer.

[Daren K Nelson]

I have posted this link here before. Like Allen I have one of the Foley retoothers, this is a video of it running. It normally sets on the bench, but to film it by myself I had to put it on the floor and mount the camera to the bench (clamped the camera in my saw filing vise of all things ) http://www.youtube.com/watch?v=lkeLXXwxRek