Bluekingfisher
Established Member
I bought an old vintage 14" brass back tenon saw made by "Clegg" from ebay a few months ago. I finally got the chance to have a look at it with a bit of refurb in mind.
The saw was in over all decent shape, I'm guessing a mid to late 19th century model? the tote just needed a clean and a light sand to remove some nicks. I removed some of the gunk with a 1/1 white spirit and meths mix, then a couple of coats of shellac followed by three coats of paste wax.
The plate was straight along its lenght, tight to the tote with minimal pitting. For a tool of its vintage it has faired reasonably well. Unfortunately the last owner has made a mess of the lfinal sharpening. The teeth were in a dreadful state with the edge cupped 3 - 4mm, Several of the teeth were also missing.
I never thought to take photos of the saw in its original state however, I decided I would have a go at re-toothing the plate. I had never until this point completely removed all the teeth from a saw, although I have sharpened my own saws for a while now, albeit leaving just enough trace of the tooth to act as a reference point for shaping/filing.
Anyways, I thought some may be interested in my attempts at rejuvinating this old tool.
The saw with the teeth filed off completely. The edge is now jointed straight, or at least as straight as I could make it
With the teeth removed, you are now on your own, as it were, no reference from the old teeth pattern to act as a guide. On the upside I now have the opportunity to decide how many teeth I want. I have several back saws with varying tooth confirgurations, although not one with 10ppi. which was what I decided on. I filed for a rip cut.
I had a look on the web to establish the best way to determine and layout the number of teeth. Paul Sellers has an interesting method on his webpage but I found a series of templates for various tooth configurations on the Norse Woodsmith page. Thanks Norse Woodsmith. You simply print off the chosen template and lay it over your saw plate.
I used double stick tape to hold the template onto the plate. In addition to holding secure, the tape acts as an aid when forming the teeth. Much like when drilling a glazed wall tile, the tape reduces the rick from the file skating or detracting off course as you file.
Here the template is fixed to the saw plate and held in the saw vice ready for the initial laying out of the teeth.
Then filing using the template as a guide. I used a xxslim 5" saw file on this saw, perhaps not ideal but it was what I had on hand. A new and sharp saw file is a must. I found out the hard way that using a used file when shaping the teeth is a receipe for disaster. You will end up forcing the cut which has an obvious and damaging effect on the teeth. The files are £3 - £4 ea. For retoothing a saw you will wear out one file. For subsequent sharpenings a file should sharpen 3 - 4 saws easily.
In case you are wondering how kong should you expect a saw to remain sharp before a touch up. Rob Cosman reckons using the saw regularly for dovetails etc should last around a year, frequent but not continual use would last 3 years. So unless you cut abrasive woods or hit nails, sharpening is in infrequent process.
After the first run.
Then with the template removed, the teeth layout is now established.
The teeth now taking shape, note the small flat spots on some of the teeth, these were removed on the next run.
Then just about ready for setting. I went for minimal set, figuring I can apply a little more if needs be.
Setting the teeth, then a final pass to sharpen the teeth. I apply Paul Sellers methology, a progressive rake over the first couple of inches of teeth, the first inch (10 ppi) shaped 15 degrees off plum, the next inch at 5 degrees. then the remainder filed plumb. It really does make starting the cut very smooth, preventing the need to draw the blade back to start the kerf line.
I used a Veritas saw file gauge this ensures an accurate and easily repeatable angle can be obtained.
The photo shows the gauge set at 15 degrees for the first 10 points.
After the final pass with the file the teeth are dressed with an abrasive diamond plate to remove the swarf from the filing.
Of course this is all very well, will it cut fast and true. The wood is Acacia, very hard and dense timber, no problems.
Of course once you have sharpened your teeth you need to have a means of protecting the newly sharpened teeth, A shrowd made by cutting a kerf in a stick is ideal.
All in all, around 2 hours from start to finish. A very straightforward and simple process. Just make sure you have plenty of light, good magnification and save at least one fresh face on your triangular file for the final pass, or you could of course have a couple of files on hand, which is what I will do in future. The files when new cut very quickly so take your time with a smooth, steady & repetative stroke.
Good luck should you try to bring that old saw back to life. I must admit I found the whole process very therapuetic.
David
The saw was in over all decent shape, I'm guessing a mid to late 19th century model? the tote just needed a clean and a light sand to remove some nicks. I removed some of the gunk with a 1/1 white spirit and meths mix, then a couple of coats of shellac followed by three coats of paste wax.
The plate was straight along its lenght, tight to the tote with minimal pitting. For a tool of its vintage it has faired reasonably well. Unfortunately the last owner has made a mess of the lfinal sharpening. The teeth were in a dreadful state with the edge cupped 3 - 4mm, Several of the teeth were also missing.
I never thought to take photos of the saw in its original state however, I decided I would have a go at re-toothing the plate. I had never until this point completely removed all the teeth from a saw, although I have sharpened my own saws for a while now, albeit leaving just enough trace of the tooth to act as a reference point for shaping/filing.
Anyways, I thought some may be interested in my attempts at rejuvinating this old tool.
The saw with the teeth filed off completely. The edge is now jointed straight, or at least as straight as I could make it
With the teeth removed, you are now on your own, as it were, no reference from the old teeth pattern to act as a guide. On the upside I now have the opportunity to decide how many teeth I want. I have several back saws with varying tooth confirgurations, although not one with 10ppi. which was what I decided on. I filed for a rip cut.
I had a look on the web to establish the best way to determine and layout the number of teeth. Paul Sellers has an interesting method on his webpage but I found a series of templates for various tooth configurations on the Norse Woodsmith page. Thanks Norse Woodsmith. You simply print off the chosen template and lay it over your saw plate.
I used double stick tape to hold the template onto the plate. In addition to holding secure, the tape acts as an aid when forming the teeth. Much like when drilling a glazed wall tile, the tape reduces the rick from the file skating or detracting off course as you file.
Here the template is fixed to the saw plate and held in the saw vice ready for the initial laying out of the teeth.
Then filing using the template as a guide. I used a xxslim 5" saw file on this saw, perhaps not ideal but it was what I had on hand. A new and sharp saw file is a must. I found out the hard way that using a used file when shaping the teeth is a receipe for disaster. You will end up forcing the cut which has an obvious and damaging effect on the teeth. The files are £3 - £4 ea. For retoothing a saw you will wear out one file. For subsequent sharpenings a file should sharpen 3 - 4 saws easily.
In case you are wondering how kong should you expect a saw to remain sharp before a touch up. Rob Cosman reckons using the saw regularly for dovetails etc should last around a year, frequent but not continual use would last 3 years. So unless you cut abrasive woods or hit nails, sharpening is in infrequent process.
After the first run.
Then with the template removed, the teeth layout is now established.
The teeth now taking shape, note the small flat spots on some of the teeth, these were removed on the next run.
Then just about ready for setting. I went for minimal set, figuring I can apply a little more if needs be.
Setting the teeth, then a final pass to sharpen the teeth. I apply Paul Sellers methology, a progressive rake over the first couple of inches of teeth, the first inch (10 ppi) shaped 15 degrees off plum, the next inch at 5 degrees. then the remainder filed plumb. It really does make starting the cut very smooth, preventing the need to draw the blade back to start the kerf line.
I used a Veritas saw file gauge this ensures an accurate and easily repeatable angle can be obtained.
The photo shows the gauge set at 15 degrees for the first 10 points.
After the final pass with the file the teeth are dressed with an abrasive diamond plate to remove the swarf from the filing.
Of course this is all very well, will it cut fast and true. The wood is Acacia, very hard and dense timber, no problems.
Of course once you have sharpened your teeth you need to have a means of protecting the newly sharpened teeth, A shrowd made by cutting a kerf in a stick is ideal.
All in all, around 2 hours from start to finish. A very straightforward and simple process. Just make sure you have plenty of light, good magnification and save at least one fresh face on your triangular file for the final pass, or you could of course have a couple of files on hand, which is what I will do in future. The files when new cut very quickly so take your time with a smooth, steady & repetative stroke.
Good luck should you try to bring that old saw back to life. I must admit I found the whole process very therapuetic.
David
