Thread: My First Backsaw Project

Hi Helmut,

Congratulations of making your first saw, very nicely done. Beech is an excellent choice for the handle material, as well, of course, it's the traditional timber for Sheffield made saws.

I have found that a punch works better than cobalt drills for making the holes in the saw plate, the one I use was an ebay cheapie something like this Heavy Duty Sheet Metal Hand Punch (NEW) - eBay, Equipment, Machinery, Metalworking, Industrial. (end time 14-Nov-10 08:20:24 AEDST)

I can't really tell from the pictures, but the bottom of the gullets on the teeth look a bit rounded, you should try and get a swiss pattern needle file for 18 tpi, that will give you a better shaped tooth than double extra slim. Actually with anything from 15tpi and above, a needle file gives better results.

Well done, looks great, and now that you are on the slippery slope, I suspect we will be seeing a lot more saws with the TS stamp!

Regards
Ray
PS How is that 14" tenon saw going? Still holding up?

Very nice work for a first effort Helmut!

What finish did you use?

I see the sides of one of the holes is a bit ragged - I'm not sure what side you drilled from, but if you want a cleaner edge finish on holes try Forstner bits.

I did not have the right file so I used a mill bastard file, I angled the file and formed the bulk of the teeth that way. I will borrow as fine file tomorrow from one of the teachers, to finish the shaping and sharpening of the teeth.

I did use a Forstner to drill the hole one just did not come out very clean. I will sand the handle down a bit so I can get a cleaner rim to the hole.

Good looking saw. I also have to get my first one finished. I came to a confidence block with cutting the small teeth so the project has been sidelined for a few months now. All I need is a kick in the a#$e to get going again.
Regards
John

Excellent effort, Helmut! Very spiffy. But be warned - one more saw & you're hooked - you'll be another member of saw-aholics unanimous before you know it!

Eyeballing those teeth, it seems to me like you have a bit too much negative rake - looks like close to 45 degrees, unless that's an optical de-lusion? When you get hold of the right files, you might want to reduce that to something like 5-8 degrees during the final tooth-forming process.

I agree with Ray - 4" DEST files are a bit too dull on the corners for teeth so fine. I'm sure they didn't used to be. I used up the last Nicholson from a box I bought many years ago, soon after I started serious saw-making. Those files had nice, sharp corners, but the ones I've been buying lately (Grobert) are not as sharp and make more rounded gullets. This is ok for a tooth pitch of 1.6mm (15tpi) or coarser, but not on finer pitches - you end up with more gullet than tooth. The pic is a section of an 18tpi saw I just sharpened, & you can see the gullets are very rounded. (They aren't as assymetrical as they look in the pic - crosscut teeth always look this way in a photograph because of the way the light reflects off the facets). I need to find a source of better files, too!

Been doing a lot of mucking about with saw teeth this last year or so, and I have started to develop a few ideas on tooth profiles & pitches. These ideas will probably change again as I go along, but at the moment, I think that a pitch of 15 tpi is as fine as you need for routine cabinet work. I do have a couple of small 18tpi saws that are very handy for some very small jobs, but for dovetailing small drawers and similar work, 15 tpi is a better choice, in my hands. Fine teeth tend to clog and not cut efficiently in a cut that is more than say 20mm wide (depending on the wood itself).

Anyway, enjoy the jouney, Helmut. The sharpening choices for saws are a lot more varied and complex than handplane blades - it's a long road!!

Cheers,

Lovely bit of work there, as far as I can tell.

I've watched this forum for some time, have learned a lot about hand tools, but rarely post, given that there are so many of you with much more knowledge than I. Please forgive my ignorance, by why would a sharply angled gullet be better than a rounded one? Table saw, chainsaw and band saw blades (can I say that in the hand tool section?) seem to work well with rounded gullets, albeit they move much faster.

Originally Posted by Jack in Nepean

Lovely bit of work there, as far as I can tell.

I've watched this forum for some time, have learned a lot about hand tools, but rarely post, given that there are so many of you with much more knowledge than I. Please forgive my ignorance, by why would a sharply angled gullet be better than a rounded one? Table saw, chainsaw and band saw blades (can I say that in the hand tool section?) seem to work well with rounded gullets, albeit they move much faster.

Jack,

I think the issue is not so much how round the bottom of the gullet is but more the depth.
On a hand saw with 18 TPI a round bottom gullet will only hold a small amount of wood shavings (once the gullet is full the saw stops cutting)
On a table saw blade the gullet is nearly 10mm deep so there is plenty of room for wood shavings (also known a saw dust )

Regards,
Chris

Originally Posted by Polie

Jack,

I think the issue is not so much how round the bottom of the gullet is but more the depth.
On a hand saw with 18 TPI a round bottom gullet will only hold a small amount of wood shavings (once the gullet is full the saw stops cutting)
On a table saw blade the gullet is nearly 10mm deep so there is plenty of room for wood shavings (also known a saw dust )

Regards,
Chris

Polie - I was going to say that's not quite right, but from a pure geometry perspective, you are, of course, dead right, when I think it through properly. The larger the radius, the smaller the section area of the gullet, so although it ends up wider with a larger diameter corner, the depth will be a bit shallower by the time the tooth point is formed.

So let me rephrase it a bit by saying that as you file the tooth to depth, you get a shallower, more rounded gullet, and small, flimsy-looking teeth if the corner radius of the file is too great. In practice, there is still plenty of gullet to hold sawdust - it's the flimsy little teeth I don't like.

Jack - you are correct that a rounded gullet is fine, and in fact desirable, as a sharp corner forms a stress point, & renders the tooth more susceptible to fatigue cracking & even breaking off if you hit a very hard knot or bit of metal. To me, the 'right' corner radius for the size of tooth you are making, gives gullets with only slightly smaller surface area than the tooth, and the upper two thirds of the leading edge of the tooth is straight & not concave. The files I have been using give a nice tooth profile for pitches between about 15 to 12 tpi, but I don't like the shape of the tooth I get at pitches of 18-20 tpi. Funny thing is, the files are sold as being suited to those tooth sizes.

Hope that makes sense....
Cheers,

I borrowed a small needle file from the Greg (teacher) today and had a talk about finishing the teeth with him. Greg has made at least 10 saws that I have seen and maintains his saws religiously. I re-filed the teeth this time I got a triangular gullet.

The saw is now cutting, I really like the 18 tpi, its much finer then any of my other saws, and it makes starting the cut much easier. The waste is very very fine, the consistency of sanding dust.

I need to touch up a few teeth that are not just right, and then I will talk to Greg again, about setting the teeth. I will post photos tomorrow.

I showed the saw to some of the other students and they like the feel of the saw and they say the handle is far more comfortable then their Lie-Nielsen saws they have, I find the LN handle to be a little emaciated in places, and I do not even have a big hand, at that.

I did not have time to finish shaping the handle but that will be tomorrows task.

In regards to the round gullet on table saw blades, I would say that they would make far more waste due to their speed, that takes up more space. Also a round hole will also be less prone to crack propagation then a sharp angular hole. A table saw blade with an angular hole would run the risk of snapping if it at a triangular hole.

John try the hack saw blade method. Use a hacksaw blade with the desired tpi. Then use double sided tape, to locate the file to the saw. Then using the file you can, to get the correct teeth spacing, with ease.

As soon as you reach the correct depth the file will start to skid on the HSS in the hacksaw blade;

Originally Posted by orraloon

I came to a confidence block with cutting the small teeth so the project has been sidelined for a few months now.

I made an indexer back in 2006, but it's easier to use a hacksaw blade for standard TPI settings.

Question: is a used hacksaw blade easier on the file than a new blade?

The hack saw blade has a good strip of HSS, you would have to have a very used up blade to make a difference. A new blade has the advantage that it still has all the paint on it, so it helps you see if you have reached the correct depth. But you can use as texter to paint an old hacksaw blade.

Originally Posted by BobL

...........
Question: is a used hacksaw blade easier on the file than a new blade?

I doubt it Bob - they are pretty damn tough all the way through!

I do use a worn one as a template for 18 tpi because that's just too fine for my chronologically-challenged eyes. I clamp both hacksaw blade & saw plate together in the saw vise with the hacksaw teeth sticking up about two-thirds of their depth above the edge of the saw plate. I then use a diamond needle file to make a deep groove on the saw plate. I press lightly against the front of each hacksaw tooth to keep the spaces accurate. Once I have a decent starter groove, I remove the hacksaw blade & file to depth using a piece of wood stuck on an ordinary file to keep the rake angle constant.

For 15 tpi & coarser, I use strips of suitably-lined paper glued to the plate. Then I go along & mark a groove at each point with the diamond file (it tends to catch & skate less, so easier to keep the lines accurate). Once each tooth is marked, I switch to an ordinary file to form the teeth as before. I find a big help is to blue the edge, so I can more easily distinguish the remaining flats from the shiny metal. That way I can keep the flat bits equal as I go to ensure even teeth. (method illustraded here: https://www.woodworkforums.com/f152/d...8-copy-120653/ )

It took me something more than an hour and a half to file my first set of teeth on a small saw, but I can do it in less than that by a long way, now and they are much more even & accurate - if I do this for another 20 years, I reckon I could probably get quite good at it!

Cheers,

Onya Helmut.