reworking Bowdon & Sons backsaw...

Re: reworking Bowdon & Sons backsaw... PICS

L. Hanson

>I've made a few back saws, but haven't rebuilt one using the method you're describing, so take the rest of this with that in mind...

You have the option of getting some new steel that is the same thickness as the old one - .025" thick steel is available from McMaster Carr (among others) and look for:

Item #9075K274

Blue-Tempered and Polished 1095 Spring Steel .025" Thick, 6" X 24" Sheet

In stock at $33.38 Each

It's good steel, hardened to the Rc48 to Rc52 range. You'd need to sand and polish the steel to remove the bluing, but that's not too tough to do.

If you decide to use the thicker piece you have, it most likely won't split the existing back unless the brass is very hard. If you want to be cautious, you can anneal the brass just as you would steel - heat it up to red hot, then let it cool slowly in a pile of ash overnight.

To get the thicker piece started into the existing back, file a slight bevel onto the top of the new blade, then mount it into a machinist's vise between two cauls and tap the back onto it:

The biggest problem you will run into is the thicker stock will drive apart the back, splitting it into a slight "V" shape - it won't want to hold the blade correctly anymore. You'll need to get out the flat hammer and re-tension the brass onto the blade again with some carefully placed hammer blows. I've got some stuff on making back saws, including installing the backs onto the blade, on my web site that might interest you. The article deals with making a saw from scratch, but at least some of it should apply in this case. See the article on Making Back Saws on my site, and click the link on the left that says "Back" to go directly to the section I'm referring to.

You'll need to be extra careful not to ding up the brass with a hammer, especially if it has a logo on it. You could maybe try using a caul of some sort, otherwise you'll need to sand and polish the brass back down to remove the hammer marks. Too much of that could remove or reduce any manufacturer's marks.

Make sure you tension the blade properly - it's not too hard, mostly just involves just making sure you get the back on straight and hammer it evenly across it's length while your installing the new blade. This would all go much easier if you use a blade that's the same size as the existing one...

Those are my thoughts on it, anyway - I hope it's of some help. YMMV.

Leif

www.norsewoodsmith.com

Re: reworking Bowdon & Sons backsaw... PICS

Ed DeLauter

>Leif,

Thanks for input. I'm thinking about relieving the top of the blade with a slight bevel. The gap at the top of the brass spline is actually just a little wider than the new blade. So the bevel would have to be at the "pinch point" to help any.

If I'm able to slide the back on and it's tight would it still be necessary to "hammer set" the brass? I'd hoping to avoid that if at all possible. The back closed shut when I took the old blade out.

I really like the Bowden Company handle otherwise I would just make a new saw entirely.

The saw you made has a very stylistic handle! Is that cherry?

Another "opportunity" I'm having is reusing the original handle bolts. They're brass with a very old screw pattern. The brass nuts just barely thread on and it is somewhat fragile. I had to drive the square shank bolts out with a small punch and that slightly deformed the end of one. A magnifying glass and super small file was needed to correct that.

Cheers,

Ed

Re: reworking Bowdon & Sons backsaw... PICS

L. Hanson

>"If I'm able to slide the back on and it's tight would it still be necessary to "hammer set" the brass? I'd hoping to avoid that if at all possible. The back closed shut when I took the old blade out. "

Oh, absolutely! That's a bonus - as long as the back is on, holding, and is straight, it's golden. I just presented some of the stuff I've run into - it might not always be the case, esp. when fixing an existing one. Just thought I'd bring it all up as things to look out for, that's all.

There are a couple methods to how the back holds the blade, and I think the method you describe on your saw is the most common on the older saws... It definitely makes repairs such as you are attempting much easier.

You can use a "starter" shim to help you get the blade started, too... Have a 1" wide (or about) piece of steel, with a long bevel on the edge - basically ground to a point - and start that into the pinched back at one end. Follow it with the blade directly behind, and remove it once the blade is started. You should be able to tap the blade into it's final position. Watch that the blade doesn't start gouging into the brass, bringing shavings of brass up - if you slightly dull the edge of the blade before you start it into the back using a muslin or deburring wheel, this can be avoided. It's the sharp edges that can "scrape" brass as you instert the new, thicker blade.

"The saw you made has a very stylistic handle! Is that cherry? "

Thanks! That one is... I made saws using cherry, walnut, and beech. The pattern was taken mostly from a 100 yr. old J. Buck saw, modified a bit to my tastes.

"Another "opportunity" I'm having is reusing the original handle bolts"

Don't you love those "opportunities"? Sometimes you can get lucky and find a similar bolt and nut off of another saw... not all were the same length. There were minor differences in the thickness of the handles amongst the different manufacturers, and in how they were made as well, with some longer than others. Sometimes, you get lucky and find a match for the diameter of the nut... and, of course - sometimes you don't. Watch it, though, not all manufacturers used the same threads, so mixing and matching doesn't always work.

If it just won't grab enough, sometimes you can tease just a bit more depth into the recess in which the head fits into a bit using a forstner bit and some careful work with a carving gouge without making it too obvious. It's a nerve-wracking process, but one option.

I hope I've been of some help. Maybe someone else will pop in with more experience than I... But in any case - good luck!

Re: reworking Bowdon & Sons backsaw... PICS

Todd Hughes

>When you aneal Brass unlike steel you heat it up and then quench it in water or let it cool in the air. No need to let it cool slow like you do steel......I think most users want a thin blade on thier dovetail saws and I would look around for for a donor blade off an old Jackson or other saw with a bad handle. Beside I would think this would look better and more realistic then a new shiny blade on a worn older vintage saw which I feel would be out of place...Todd

Way to go, Leif!

Bob Smalser, Seabeck, WA

>nm

This saw won't be used for

Ed DeLauter

>dovetails. I use japanese dozukis for that.

It will cut tenon cheeks and what have you.

As for the aesthetics you make a good point.

Finding an old "Jackson" with a bad handle around here is pretty rare. This area (Ozarks N. Arkansas)is running very short on old ww handtools. It used to be frustrating. The folks who live in the northeast are spoiled in this regard.

I am foregoing the annealing process. I'd probably screw it up with my acetylene torch. Ha.

The metalurgical differences in steel/brass are interesting.

One cool thing about ww & tools is that you constantly are learning something new!

Cheers,

Ed

Re: This saw won't be used for

Fred Peake

>Ed, you might try the upcomming Annual Ground Hog Day meet on Feb 12, in Bentonville, AR. It is a joint SWTCA and MWTCA old tools meet. Usually has lots of tables and I've gotten some really nice saws there in the past.

Thanks Fred. It's 150 miles or

Ed DeLauter

>so over there but I make go anyway.

Cheers,

Ed