Filing dovetail or tenon saws

[Michael Ray Smith]

I'm jointing and sharpening a Cincinnati Saw Company back saw. I'm having to reshape the teeth considerably, but I'm leaving it at the original 13 ppi. What's the best tooth geometry for dovetails saws and for tenon saws?

[Chris Griggs]

Assuming you are filing these for rip cuts, for north american hardwoods, about 5 degrees of rake is a nice compromise of speed and ease of use.

[Jim Koepke]

For dovetails, my saws get a rake of 8º. This is easy to start. Cutting for dovetails is seldom more than an inch, so speed isn't of the essence.

If you are doing more tenons, then maybe 5º as Chris suggests would be appreciated for the quicker, more aggressive, cutting provided.

This is where having a few extra saws comes in to allow for different tooth geometries.

Another consideration would be how deep and thick the saw plate happens to be. If it is deep and thick, make it a tenon saw. It can be used for dovetails until a saw better suited for dovetails comes your way. Conversely, if it has a shallow and thin plate, make a dovetail saw that can cut tenons until a better saw for that purpose comes along.

jtk

[Michael Ray Smith]

For dovetails, my saws get a rake of 8º. This is easy to start. Cutting for dovetails is seldom more than an inch, so speed isn't of the essence.

If you are doing more tenons, then maybe 5º as Chris suggests would be appreciated for the quicker, more aggressive, cutting provided.

This is where having a few extra saws comes in to allow for different tooth geometries.

Another consideration would be how deep and thick the saw plate happens to be. If it is deep and thick, make it a tenon saw. It can be used for dovetails until a saw better suited for dovetails comes your way. Conversely, if it has a shallow and thin plate, make a dovetail saw that can cut tenons until a better saw for that purpose comes along.

jtk

Thanks, Jim, especially for pointing out the additional consideration. The blade on this one is about 4 inches wide, from the teeth to the inside edge of the back, and fairly thick (don't have it available to me right now, so I can't be more precise), so I think I'll take your advice and consider it a tenon saw. Between you and Chris, the consensus seems to be about 5 degrees of rake. I assume I should stick with 0 degrees fleam -- correct?

[Chris Griggs]

I would start out with 0 fleam just because its easier. I like to add a bit of fleam (<5) into my ripping saws sometimes, just because it can smooth out the cut, but its by no means necessary. You get a touch fleam anyway just by the fact that's hand filed and what you get from human error even when you are trying for 0 fleam is often just the perfect amount.

Keep things as simple as possible for now. Work on getting even teeth and a consistent rake angle.

[Jim Koepke]

I assume I should stick with 0 degrees fleam -- correct?

It is like Chris says, easier. Since I have a few saws already at 0º my last saw was given about 5º of fleam. The plate was shallow and thick, ~0.032".

It is aggressive for both ripping and crosscutting. It gets a lot of use for small cuts since it is a rather small saw.

Here is a link to the post on building this saw:

http://www.sawmillcreek.org/showthread.php?180712-Back-Saw-Build

Looking over this old post reminds me that a little fleam on a rip saw does seem to make the exit side of a cut cleaner.

jtk