Saw sharpening.

[Honest John]

Spent some short time sharpening a couple of back saws that I had picked up for a few pounds today. The results were better than I had expected, due mainly I believe because I had made a myself a saw vice so that I could mount the saw plates at a height that I could see clearly even with my less than perfect eyes, and manage better the tooth geometry. Any way, the point of the post. I inherited a couple of hard point saws from my dad after he had died some years ago and I had not thrown them out sort of because they were his? My query is,... is it possible to grind off the teeth and then recut and sharpen the plate? I'm thinking that it's only the teeth that are hardened and the rest of the plate could be used. Has anyone tried this?

 

[ColeyS1]

Not sure, but I'm watching with interest. I found my first ever hardpoint saw a few years ago- it'd be nice if I could get it sharp again.
Coley

 

[Derek Cohen (Perth Oz)]

How will you grind away the teeth without affecting the hardness of the saw plate?

Regards from Perth

Derek

 

[undergroundhunter]

As I understand it the plate of the saw will not hold a good edge as the steel is not the same as a resharpenable saw. One of the advantages of hardening the teeth like they do is that they can use lower quality (and cheaper) steel. BY all means give it a go but I don't think you will have much success. Maybe just hang them on the wall.

Matt

 

[Dovetaildave]

A very interesting idea, especially for those who do a bit of rough work or are just starting woodworking, or moving into finer woodworking, as it always seems to come down to money invested in tooling and equipment at the outset.

If a handsaw, a quick test to find out the steel quality question, by sharpening the non hardened side...............and flipping the handle for the test cut :wink:

if quality and flipping works, maybe a tenon saw plate can be released from it's "Back" and flipped :?: might have to loose a little length to allow for new bolt and handle connection tho.

I'm not experienced enough to sharpen well, let alone re-cut some teeth.

Regards,
Dave

 

[Sheffield Tony]

I would say yes. Hardpoint saw steel makes perfectly good scratch stocks and cabinet scrapers so it can't be all bad. I'm sure the reason for hardpoint saws was avoiding the needed for the user to sharpen them, not particularly to use cheaper steel. Can't imagine a modern spring steel amounts to much of the cost.

Grinding the teeth off could be a problem. If you don't mind losing a bit more metal, you could hacksaw it off behind the hardened toothline. Or it might be possible to grind them off with the plate clamped between heavy bits of angle iron as a heatsink ?

 

[Cheshirechappie]

It may be possible, but is it worth it? There's a fair bit of work involved, plus the cost of a saw file and whatever grinding consumables it takes to remove the old teeth.

It has been suggested in the past that some hardpoints can have another life by sharpening them with a diamond file. However, there's a limit to how much you can file off without getting into the softer metal, so there's maybe only one more life to be had that way - at the cost of a diamond file.

My inner tightwad rather likes the idea of cheating the big corporations by extending the life of a disposable, but my inner Scrooge grumbles about the cost of the tools required and the time it would take. If you're going to invest the time in sharpening a saw, it might as well be a 'nice' one.

Maybe the pragmatic approach is just to buy another hardpoint and get on with some woodwork.

 

[pedder]

You can temper the saw blades at 220°C -250°c in the oven till they get blue. Then you can file the teeth.

Or cut the old teeth of with a shear

Or use a diamond triangular file and file them.

 

[Mike Jordan]

Think about it! Hard point saws were only a success in the first place because the time taken to sharpen and set a conventional saw costs a tradesman more than the cost of a new hard edge.
Mike.

 

[Honest John]

Thanks to all for your replies. I don't believe you could make any economic case for this proposed action. My days of paid employment are behind me and I look forward to being creative in my retirement . I spend quite a bit on tools ( wife not reading this !) and although I woodnt consider myself wealthy, I have no problem funding any tool purchases I want. What I was really interested in was whether it was possible to recondition and sharpen these throw away items thereby making them useful again. Cost in terms of time spent is unimportant. My understanding is that just the teeth are electrically heated and hardened. I would expect the plate to be similar to many other saws, on the basis that that is what would be available to toolmakers? I would expect to either hacksaw 6mm off the plate behind the teeth, effectively cutting off the teeth, or my more likely approach of clamping between steel bar or angle as has been suggested, with about 6mm extending, and grinding off with an angle grinder. Il put this project on to the back boiler and when I get a moment il give it a go. As I get older I get more suspicious about manufacturers that make things by the million, sell them very competitively, and then expect you to buy another one when it gets blunt. That makes sense if your living depends on it. **** the saw probably costs less than a "sawdoctor" would charge for a sharpen.....if you could find a saw doctor!

 

[ED65]

You can temper the saw blades at 220°C -250°c in the oven till they get blue. Then you can file the teeth.

This is an air-hardening steel, does tempering work the same way as on quenching steels?

Very easy to find out empirically of course, just wondering out loud

 

[ColeyS1]

Perhaps a diamond file is the solution for me. I think the handles moulded onto the blade, so I wouldn't be able to put it in the oven.
I quite like the idea that instead of it being a rusty ornament on the wall, that it could actually cut again.
It was a nice handsaw to learn with. I use to sit on my dad's car bonnet in the garage and saw wood in the engineering vice. I remember this one time, I was in full swing, sawing away and managed to cut my knee with it. I never sat down on the job after that ! Instead I use to push the car out the garage and up the hill,far enough so I could close the garage door.
Sometimes it'd take 2 or 3 trys to get it far enough up the hill,the final challenge was wedging a log under the wheel so it didn't roll back down again :lol: Oh the memories- Happy days!
Coley

 

[pedder]

You can temper the saw blades at 220°C -250°c in the oven till they get blue. Then you can file the teeth.

This is an air-hardening steel, does tempering work the same way as on quenching steels?

Very easy to find out empirically of course, just wondering out loud

I don't know how it works (and I don't care). I tried it, it worked, I was happy.
(First test was on laser toothed blades from a friend).

 

[ED65]

I don't know how it works (and I don't care). I tried it, it worked, I was happy.

Good to know, ta!

 

[Eric The Viking]

Or use a diamond triangular file and file them.

Which is what I've done in the past, with mixed results, including some success.

The problem with it, I find, is the files: the cheap ones use diamond dust that isn't very well graded, and mine have lumps sticking out above the main line of chips. If you know where those are, you can avoid them.

It works for me: I've even done it with the strange teeth on a multi-tool blade (needed a certain profile in a rush over a week-end). You won't get as good results as either the originals or doing a traditional saw with good files, but it does work.

I guess if you spent a lot on decent diamond needle files that would yield better results.

E. (the ole' skinflint!)

PS: I certainly wouldn't risk my few remaining decent saw files on hardened teeth: best outcome, they won't cut, worst: you'll ruin the files. You might try abrasive discs in a Dremel-type tool though, as people seem to get those to work well with bandsaw blades...