Over a year ago I picked up this Wenzloff dovetail saw on eBay. It was sold as 'used' with a note that it had some cosmetic issues.
On first using the saw I noted that it really, really needed a tune up. The teeth needed jointing and sharpening in the worst way. I put the saw away, using it only as a pattern.
Today I pulled the saw out to give it a rework. The first thing I noted was that the screws were unbelievably tight. I really thought I was going to break them off in removing them. It's clear that the previous owner also had some troubles as the slots of both nuts were burred. A surprising amount of burring was present on the clock-wise faces of the screw slots, obviously somebody had put some effort into tightening them.
I finally got the screws out and removed the handle to find that the entire surface of the blade under the handle was covered with a smooth layer of orange rust. Obviously something strange had happened here. Using a fine flap wheel followed by diamond lapping I got the blade looking better, though there was still some pitting and remaining stains.
I reassembled the saw, tightened the screws reasonably and found that the handle was now loose on the saw plate. I tried tightening the screws a bit but there was no improvement. Removing the rust and the friction between the handle and the blade had made the saw worse than when I started - the handle now moved about 3/16" of an inch up and down at the top horn.
I pulled the saw apart again and found that the screw shanks measured about 5/32" and the holes in the saw plate measured about 3/16". The slop in the fit-up of the screws combined with the slippery and hard cocobolo (I think) handle allowed the handle to move around far more than I found comfortable.
So rather than consign the saw to a box I decided to make it functional again by adding my stainless steel bushings. The supplied screw shanks were a little smaller than I'd like but I decided to do the retrofit anyway.
The first step was to push the handle onto the plate/back assembly and ensure that the back was fully seated in the slot.
I noted immediately that the toe-most screw hole in the handle aligned the best with the corresponding hole in the saw plate. The heel-most hole was way out of alignment, something like 25% of the radius of the hole.
Starting with the toe-most hole and using a #1 tapered spiral flute reamer I slowly opened out the hole in the plate.
I then progressively opened the hole using successive reamers 2 through 5 until the bushing was close to fitting. I gradually opened the hole using the #5 reamer by turning it about 1/2 turn, testing the fit of the bushing, and then giving another half turn. Finally I got the first bushing seated in the handle such that the face of the bushing was seated just below the square mortise for the screw.
And here's the off-side showing that the bushing stops before intruding into the mortise for the nut.
After seating the bushing I put the front screw and nut in place to hold everything steady while I worked on the second screw hole. This hole alignment was really bad.
Again, using the reamers I re-centered the holes and worked my way up to the #5 reamer.
And seated the second bushing.
Next I decided to see if I could correct some of the cosmetic defects.
Sanding both sides carefully I was able to remove most of the burrs from the nut slots and cleaned up the fit of the heads to the handle.
I then jointed, filed and set the saw, wiped on some Danish oil finish and gave it a test.
Overall I'm pleased with the result. I saved the saw from the creeping rot under the handle and restored it to functionality. Now I need never worry about tightening these screws again so in my opinion it is now better than new.
.
On first using the saw I noted that it really, really needed a tune up. The teeth needed jointing and sharpening in the worst way. I put the saw away, using it only as a pattern.
Today I pulled the saw out to give it a rework. The first thing I noted was that the screws were unbelievably tight. I really thought I was going to break them off in removing them. It's clear that the previous owner also had some troubles as the slots of both nuts were burred. A surprising amount of burring was present on the clock-wise faces of the screw slots, obviously somebody had put some effort into tightening them.
I finally got the screws out and removed the handle to find that the entire surface of the blade under the handle was covered with a smooth layer of orange rust. Obviously something strange had happened here. Using a fine flap wheel followed by diamond lapping I got the blade looking better, though there was still some pitting and remaining stains.
I reassembled the saw, tightened the screws reasonably and found that the handle was now loose on the saw plate. I tried tightening the screws a bit but there was no improvement. Removing the rust and the friction between the handle and the blade had made the saw worse than when I started - the handle now moved about 3/16" of an inch up and down at the top horn.
I pulled the saw apart again and found that the screw shanks measured about 5/32" and the holes in the saw plate measured about 3/16". The slop in the fit-up of the screws combined with the slippery and hard cocobolo (I think) handle allowed the handle to move around far more than I found comfortable.
So rather than consign the saw to a box I decided to make it functional again by adding my stainless steel bushings. The supplied screw shanks were a little smaller than I'd like but I decided to do the retrofit anyway.
The first step was to push the handle onto the plate/back assembly and ensure that the back was fully seated in the slot.
I noted immediately that the toe-most screw hole in the handle aligned the best with the corresponding hole in the saw plate. The heel-most hole was way out of alignment, something like 25% of the radius of the hole.
Starting with the toe-most hole and using a #1 tapered spiral flute reamer I slowly opened out the hole in the plate.
I then progressively opened the hole using successive reamers 2 through 5 until the bushing was close to fitting. I gradually opened the hole using the #5 reamer by turning it about 1/2 turn, testing the fit of the bushing, and then giving another half turn. Finally I got the first bushing seated in the handle such that the face of the bushing was seated just below the square mortise for the screw.
And here's the off-side showing that the bushing stops before intruding into the mortise for the nut.
After seating the bushing I put the front screw and nut in place to hold everything steady while I worked on the second screw hole. This hole alignment was really bad.
Again, using the reamers I re-centered the holes and worked my way up to the #5 reamer.
And seated the second bushing.
Next I decided to see if I could correct some of the cosmetic defects.
Sanding both sides carefully I was able to remove most of the burrs from the nut slots and cleaned up the fit of the heads to the handle.
I then jointed, filed and set the saw, wiped on some Danish oil finish and gave it a test.
Overall I'm pleased with the result. I saved the saw from the creeping rot under the handle and restored it to functionality. Now I need never worry about tightening these screws again so in my opinion it is now better than new.
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