Made a backsaw

[Justin Green]

You guys have created a monster. I see all these posts about people making their own saws and I had to give it a shot this weekend. I just finished filing and setting and sharpening the teeth, from scratch. This is the drywall knife/14guage steel back saw with maple handle.

It starts easily and cuts fast, but it has a tendency to curve to the right after I get about an inch and a half into the cut. The kerf is nice and thin, but there is a little excessive tear-out on the back side. I probably filed the teeth too aggressively. Aside from the curved cutting and tear-out, I think I like it. I also need to find some proper saw nuts for it. It has aluminum binding screws and posts holding it together now. They're sturdy, but ugly.

I still want a Wenzloff, though. Or a LN. It will happen.

[Bill Rusnak]

[quote=Justin Green;1076945]I also need to find some proper saw nuts for it. quote]

Nice job. Tools for Working Wood sells 7/8" saw nut assemblies. http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=PROD&Store_Code=toolshop&Product_Code=GT-CKIT.XX&Category_Code=TMQ


Can you give us any construction details?

Bill

[Justin Green]

I didn't photo the entire process because I didn't know how it would turn out.

Yeah, the blade is from a borg drywall knife that I disassembled. I shaped the blade a bit near the heel with the grinder. The back was made, based on posts by Robert Rozaieski, from 14 gage steel I also found at borg. It was pre-bent to 90 degrees and I just needed to fold it the rest of the way. Either Robert is 3 times the man I am, or my vise is weak, but my vise would not budge the steel, so I hammered it, leaving a lot of tracks along the back, as you can see. I used a 4 pound hammer and it does a lot of the work for you.

The handle was fun, too. I drilled the radiused parts like other tutorials here have shown and I rough cut the rest out with my jigsaw. I don't own a bandsaw. I cut the slot for the blade and chiseled out the spade for the back. To get in close on the rest of the curves, I used the coping saw, and then went at it with rasps, files, small sanding drum on the drill press. The sanding drum makes quick work of the curves, but it will easily mess up a nice line in a hurry.

I haven't really finished the saw yet. I have a couple of coats of minwax oil finish and snapped the photos in between coats, so the handle is getting more coats of finish.

It's pretty rudimentary, and since it's not tracking great, I don't trust it to use it just yet. I need to play with the set a bit more.

[Bill Rusnak]

Wow, a drywall knife saw blade. Is your middle name MacGyver?

[Justin Green]

Ha! No, twas not my idea! I found this post from a while back and was inspired:

http://www.sawmillcreek.org/showthread.php?t=96443&highlight=dovetail

Also, it's 15 teeth per inch. I work with Microsoft Excel all day long and you can resize the columns and add borders and print it out. Nice tooth spacing guide that I just taped on the blade. It worked well. I did completely lay waste to a small Nicholson file while making the teeth.

[Ray Gardiner]

Hi Justin,

Nice work, congratulations! it's a nice looking saw.

Provided everything else is ok, you can straighten the cut (tracking) , by lightly stoning the side that it's cutting towards.



Regards
Ray

[Robert Rozaieski]

Nice job Justin! Glad it worked out for you. As Ray said. Stone the offending side one pass from heel to toe and try the cut again. You likely have more set on the offending side and this will make it track in that direction. Just make one light pass at a time between test cuts and use a hard, fine stone (the saw teeth will groove a waterstone). I use a hard Arkansas slip.

[Tony Zaffuto]

Another push down the slope to the rest of us thinking about making a saw! Very nice job, especially since this is your first try!

Tony Z.

[Justin Green]

Thanks guys! This was a fun project. I wish I was a little better at getting the fit and finish right, but I suppose that comes with having some practice under the belt!

Oh, and evaporust takes the bluing off of the blades, if anyone needs that tidbit of information. Just make sure you have a container long enough for the saw to be fully immersed, or you end up with lines on your blade like the ones in the photo.

I'll try stoning off one side a hair to see if that works. Even though I went slowly cutting the teeth, some of them ended up a bit uneven, so I might joint the saw again and resharpen and reset the teeth. Better practice on this than an expensive saw!

[Cliff Rohrabacher]

Also, it's 15 teeth per inch. I work with Microsoft Excel all day long and you can resize the columns and add borders and print it out. Nice tooth spacing guide that I just taped on the blade. It worked well. I did completely lay waste to a small Nicholson file while making the teeth.

I tried that approach and failed entirely. I failed over and over. I failed every time.
My work around was to build a saw-toothing machine that relied on the thread pitch of the All-Thread lead screw to get the teeth cut. I can swap the lead screw out for a different thread pitch. Nothing like mechanical certainty.

I too built mine from a drywall blade.
http://www.sawmillcreek.org/showthread.php?t=98825&highlight=cobbled

I rather suspect that the "drift" you experienced is more from burrs that needed to be stoned off before you set the teeth. My toother only cuts from one side so all my burrs were all on the one side. A good Stoning took care of that just fine. Some people will flip the saw blade and file from the other side to remove, neutralize, or even out the application of the burs

[Justin Green]

Wow, Cliff! That's an impressive machine!

I can't see any curves in the blade, but I'm really concerned that the blade's crooked. It doesn't appear crooked next to a straight edge, but when it gets about an inch to an inch and a half into the cut, it starts the drift. I will stone the sides when I get home, and I'm considering practicing a complete jointing and resharpening session just for practice anyways.

I filed all of my teeth from one side, and I did notice some burrs on the back side. Let me get this straight - the burr was on the left hand side of the blade, but the saw drifts to the right. Isn't that backwards?

[george wilson]

I never stone the burrs off saw teeth. I did when I was young and excessive. If the teeth are properly set,and the blade is flat,it will not drift. Stoning will only serve to thin out the metal's gauge at the teeth. Once the teeth are set,how are you going to ever stone it again? You would have to hammer the set down flat,and later re set the teeth,which would cause teeth to break off. If you must demand to equalise the burr,file every other tooth from 1 side of the saw. Then,turn the saw around and file the in between teeth from the other side.

That little burr will very soon get wiped off by sawing wood. If you are getting drift,something is wrong with the set of the teeth,the teeth themselves,or a bend in the vertical plane,of the saw.

The only application of using a burr on saw teeth,was in the marquetry maker's blade. They made their own blades from watch springs,and left the burr on the teeth to serve as a set ,because their teeth were too tiny to set in the usual way. With the very large number of teeth per inch,and only sawing veneer,the "rag" of the blade,as they called it,lasted longer.

[Justin Green]

If something is wrong in the vertical plane, is that a correctable situation? It certainly doesn't appear to have a bend between the back and teeth.

The other odd thing that happens is that one or two cuts will be straight, and the next couple drift. Could be user error (there's always the high possibility that I don't know what I'm doing).

[Zahid Naqvi]

Justin that is a great post. I had seen that post you referenced but never got the courage to go out and make a saw from a drywall knife.

So George what is the recommended fix if the saw drifts one way or the other. Assuming the blade is vertical and without bends.

[george wilson]

Zahid,carefully look at the saw teeth from both sides. Sometimes they look different from each side. This is due to not filing the teeth with the file held perfectly horizontal. Of course,I can't examine the saw in question,but have seen quite a few saws with teeth that were filed with the file held uphill.

The set must be equal on both sides.If the set is wider on one side,the saw will drift towards the wider set side,as it is the path of least resistance.Properly setting up a saw's teeth requires careful observation,and development of skill. I have seen plenty of otherwise competent craftsmen who cannot properly file and set saws.

It was so bad at the museum,I had to get the director to issue an edict that all saws had to be sharpened by the toolmaker. I had to cut teeth off and punch new teeth,wasting 1/2" of saw blade from the mess some people made of our handmade saws. There was 1 shop that could handle it,and I had trained that person,Marcus Hansen,my old journeyman.

[Justin Green]

Now that I'm home to look at the saw, I believe set is the issue. Learning to set a saw with small dovetail teeth is probably not the best starting point.

Believe me, Zahid, you will probably end up with a product much nicer than mine. There's a huge gap between making a saw and making something that looks like a saw! But it's a cheap way to learn without ruining a nicer saw or an old saw. It's a drywall knife, afterall!

[george wilson]

Justin,I recommend that the back edge of the saw blade should not extend back so far that the hand can come in contact with it when sawing. Take a careful look at some real good backsaws.

[Justin Green]

Thanks George. I did manage to joint the initial teeth a bit and cleaned them up, filing every other tooth from one side and then the other. Works much better now!

[Dan Carroll]

Thanks guys! This was a fun project. I wish I was a little better at getting the fit and finish right, but I suppose that comes with having some practice under the belt!

Oh, and evaporust takes the bluing off of the blades, if anyone needs that tidbit of information. Just make sure you have a container long enough for the saw to be fully immersed, or you end up with lines on your blade like the ones in the photo.

I'll try stoning off one side a hair to see if that works. Even though I went slowly cutting the teeth, some of them ended up a bit uneven, so I might joint the saw again and resharpen and reset the teeth. Better practice on this than an expensive saw!


I find wall paper soaking vats work for this job and they are cheap!

[Justin Green]

I find wall paper soaking vats work for this job and they are cheap!

I will definitely look into that! I had the evaporust in an old kitty litter container because it was a good size for plane parts, frogs, etc., but it's not so good for long, narrow objects.

[David Gendron]

I have two LN saws for sale, one is a dovetail filedrip and the other one is a carcass saw filed xc, allmost new and in original box(the dove tail sawhave some tarnish on the blade! but looking at the saw you made, I'm not sure you need a LN...
David

[george wilson]

We have a tupperware type container that seems to be for loaves of bread. It would hold most backsaw blades,except for tenon saws,and would take a lot less solution. There may be less expensive chemicals than Evaporust available. I know a guy who took off gun blue by soaking them in vinegar. Gun blue is a lot harder to remove than fire blue,which is exceedingly thin.I haven't tried it myself,but it worked for him.It would be less hard to "kill" than dilute muriatic acid,or other more powerful acids,too.

[Ray Gardiner]

Hi Justin,

A better way to remove the bluing is weak phosphoric acid, just a tiny bit on a rag and it wipes off like magic. (I should acknowledge that Mike Wenzloff put me onto this little bit of magic). After wiping, scrub thoroughly with running water and then dry and a bit of WD40 and follow up with a wax polish.

Regards
Ray

[george wilson]

Probably even lemon juice would remove the blue in a pinch.Lemon juice is used by some damascus steel knife makers to etch the blades,showing the layering. Actually,I've done the same thing with Clorox,and found it to be more agressive than the lemon juice,in bringing out the damascus pattern. Probably would take off the blue,too,although I'd test it on a scrap of spring steel first. Some chemicals will turn the steel an unsightly gray color instead of leaving it bright.

[Justin Green]

Thanks again! I'll try that. I had bought enough materials to make two saws, and there's still one that's in the blue.