a tale of five kerfs

As a continuation from this post, there are times when you’re doing tool surgery when you have to make choices. In my experience, however, decisions about how long the saw should be, how much cant it should have, the hang of the handle, etc. are much more about looks and feel than a series of correct measurements and so I like to do the bulk of that work visually.

In restoring this chopped down miter saw I made most of the choices based on what I had to work with. The length of the spine was made clear by what was already missing. The overall length was based on that and tweaked until the saw felt more balanced. The hang of the handle is not optimal, but adequate, so I’m leaving that alone for now.

image

The worth of a saw, however, is primarily in what is not there. Specifically, what is not there when the saw has finished its work.

Can it cut straight and true? What is the size of the kerf? What surfaces are left behind?

The plate on this saw is thicker than I would like, so I’ll just start there. I ground it down a little on the belt sander (confession) and then did some more material removal by hand, but it’s not enough. There is still more steel to go. I’ll probably get some aggressive grit paper and see if I can’t take the width down some more.

That concern has a lot to do with how the saw performs in the cut. The reason for taper grinding is so that the saw is thinner at the back than at the teeth allowing it to move more freely in the kerf. This saw seemed to have absolutely no taper on that thick plate.

The next consideration is tooth geometry. For the time being I have decided to file this one rip, at about 10 ppi. The teeth had no discernible filing pattern when I got the saw. It was as if someone started to file it cross-cut, got half way through and then quit. There’s plenty of steel there so I have options should I ever want to change it, but in my experience a rip saw is loads more versatile, and with the thickness of this plate it made sense to turn it into a beefy tenon saw for larger work.

After a quick file and set here’s the verdict. The no.4 is second in from the right. I stacked it up against other (rip filed) saws in my shop just for reference. From the left the kerfs are made by my Veritas dovetail saw, my normal tenon saw (no name rescue), my Disston no. 7 panel saw, the no. 4 and finally my D-16 rip saw.
image

As you can see it’s not the finest of the bunch, but it does drop comfortably into the kerf left by my D-16. It is virtually identical to the kerf left by my no. 7 panel saw. It cuts with relative ease (to when I first started) but it still binds a little in the kerf so my hope is to taper the plate a little more and see if I can’t tune it up to be a regular user.

Advertisements

One thought on “a tale of five kerfs

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s