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Rehabbing an 8" Disston backsaw

The smaller Disston 8" backsaws don't show up at an affordable price too often (at least for me they don't!) and when I saw this mis-labeled saw (it was advertised as a 10" saw, the seller had measured it's total length rather than blade length) on ebay some time ago I placed a lowball bid, fully not expecting to get the saw. Yet, I won - I think I got it for around $18 including shipping. Here's the saw as it arrived:

The saw: bought for under $20 - though the price turned out too good to be true.|

The saw: bought for under $20 - though the price turned out too good to be true.|

Upon closer inspection, my elation was short-lived. The saw had some serious flaws. What I though was simply dirt or discoloration turned out to be pitting, and quite severe, as you can see in the next photo.

Really the pits.: You can see the extent of the pitting better in this photo

The pits: The saw showed evidence of heavy rust - the steel of the back and the blade was severely pitted.

The pits in the steel back don't hurt anything, but the blade was simply too pitted to use. It would have to be replaced - a bummer, because I was really hoping it was only discoloration. You can't really see from the photo just how bad the pitting truly was, but trust me - it was bad.

But - there was another problem that was also troubling - both sides of the handle had stress cracks from the front nut to the front edge of the handle:

The splits: the handle had stress cracks on each side.

The splits: the handle had stress cracks on each side.

Since I was already replacing the blade - well, it just didn't seem right to replace the handle too - there wouldn't be much of the original saw left. I decided to repair the cracks.

Often I would use hide glue to make the repair - but this time I went with a good CA glue. Both will work fine, but tonight I wanted to work quickly - and the CA was handy. I worked the glue into the crack with a piece of paper, and poured enough onto the crack to fill into the crack, then clamped the crack together with a spring clamp.

Glue up: CA to fill the cracks

Glue up: CA to fill the cracks

Once the glue dried, I used a file to remove the excess glue, filing down to the surrounding wood. It looks quite obvious - but that's just how it will be. The crack was old enough that a seamless join wasn't really possible anyway. The finish will reduce it's visibility, though.

Repaired: Excess glue is removed using a file.

Repaired: Excess glue is removed using a file.

To reduce the pitting and improve the appearance of the back, I used a deburring wheel to polish it. I cut a new blade and cut new teeth at 15 tpi (rip profile) in it. I also tried a new etching method - more on that another time - that wasn't completely successful, though I believe that I just didn't give the etchant enough time. I also took the time with a chisel to shave off the inside of the mortise so the handle would fit better onto the blade - that way the crack wouldn't be under undue pressure and possibly crack again.

Etching: A new logo for a new blade.

Etching: A new logo for a new blade.

I finished the handle with an amber shellac - it closely approximates the original color, is easy to apply, and helps to cover the cracks - of which here's a photo:

The repaired handle: the crack is still evident, but structurally sound.

The repaired handle: the crack is still evident, but structurally sound.

You can still see the crack - but it's structurally sound now and shouldn't be a problem.

Here's a full shot of the two sides of the finished saw:

The repaired saw: ready for action.

The repaired saw: ready for action.

So - with a new blade, it's not technically a Disston anymore - but it's a good saw, and is very comfortable. This is my favorite Disston backsaw model, the one I find most comfortable for using when cutting dovetails. It's too short, and too fine for most tenons, so it's pretty much a single-purpose saw - but it's the type I reach for almost without fail when the need arises.

 

Comments

Very nice, as usual. When do we get the details on the new etching process? I'm very interested to see how you feel it compares to the etching you've already written about.

Thanks...

 Might be a bit before I do a thing on the new etching process - however to whet your appetite, you can take a look at the homemade electro-etching apparatus I built using plans available on the web:

Etching Machine

 Leif

Leif-

Any experience with trying to joint/retooth a saw plate that is pitted? Looks like some of my teeth were broken off, either through abuse or weakened due to severe pitting in that area. Trying to decide if jointing and re-toothing would work, or if I need to get a new plate.  Based on your decision, I guess I know the answer, but thought I'd ask in case you just went that route because you were super OCD/retentive (^:

Thanks,

Sean

OCD?  Me?  ;-)    I think anyone with the patience for sharpening saws can benefit from a bit of OCD...

If the pitting isn't too deep, then it's not too big of a deal.  It's when it gets deep enough that it can effect both the strength of the plate and how sharp you can get it - there is a point beyond where it's not worth it.  If it's a common saw, that line is easier to determine. 

On the saw in this article - while it doesn't show too well in the photos, the pits were *really* deep.  I think I could have just went ahead and sharpened it and still had a pretty fair performing saw, though...  Just that it sure wouldn't have been very purty...  The pits were deep enough too - on both sides - that it did cause me some concern, so this blade had to go, IMO.

HTH

Leif