Reducing the set on my tenon saw (and becoming a butcher)

This started out as a attempt at minor surgery. Actually it should have been more like taking a couple of paracetamol; perfectly safe and simple enough that anyone could do it. By the end of the process however, it had gone beyond major surgery to what could best be described as savage butchery.

It all started simply enough. I don’t own a good tenon or dovetail saw, and have been vacillating between spending the money on a good new saw (which I’d have to sharpen down the track anyway), or get a used saw and learn to sharpen sooner rather than later, or build a saw from scratch.

Anyway, back to my current saw. It’s a simply Bahco tenon saw with impulse hardened teeth. For those that don’t know what that means, the teeth (not the whole saw plate) are hardened so that the saw stays sharp longer, but when it goes blunt, there’s nothing you can do.

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I’ve been using this saw for a year or so, and while I’ve been able to successfully cut rather good joinery with it, the wide set makes the blade wobble in the kerf whilst trying to cut a straight line. In this case, the 0.75 mm plate was cutting a 1.2 mm kerf. You can see from the photos below how much play there was with the saw in the cut.

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I’d read about this fantastic technique where you fold a piece of normal printer paper over the blade and squeeze the teeth between two steel plates in a vice. The idea being that the teeth pierce the paper as the vice closes but the plate won’t, so you end up with a set the width of a piece of paper. I did refer to several sources and all appeared legitimate (unlike fixing broken porcelain by soaking it in milk… but that’s a story for another day).

Because my vice jaws are rather the worse for ware, I’d need something a little more uniform. Looking around the shed I found some shelf brackets that I’d welded up from RHS. I thought that would be strong enough to do the job. After tightening it nice and hard, at the heal, mid section and toe, I unwrapped with an air of anticipation to see what the procedure had delivered. The tooth perforations on the paper were nice and uniform, so assumed sufficient pressure had been applied along the length of the blade.

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Hmmmm, subsequent measuring showed 0.00 mm reduction in set. Not what I was expecting and a little disappointing if truth be told. Hmmm, what to do? And this is where things started taking a turn for the worse. Rather than meticulously researching my next options, as is my natural disposition, I recalled that I’d read somewhere that you can reduce set with a pair of hammers, and threw caution to the wind.

I dutifully clamped my large claw hammer in the vice, and gently, using my ball-peen hammer ran across all the teeth of my saw. One pass on each side.

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The first test cut was great. I can’t tell you what the set reduction was, because I considered it pointless measuring as any teeth I did measure would provide an unrepresentative sample of the results due to the uncontrolled process. The kerf was noticeably thinner when viewed next to some initial control cuts.

And this is where the sad tale starts it’s downward spiral. There was still some set, and started wondering what it would be like to use a no-set saw (I’d been reading about cutting saw plates you see, and some people like having no set). So back to the hammers. Whoah! Once the cut was started (at the correct angle, hmmm), I could follow a line with eyes closed. This was great! The only issue was that if I did a deep cut, after a while it would try and track to the left and bind. No problem I thought, it just needs a touch up with the hammer on the left side to bring what errant teeth there are into line. And just to be safe, I went over the other side again too. It was about half way through the second side when I noted that rather than hammering to the same plane as the saw plate, I was angling the hammer into the plate. Surely I wasn’t creating the first tenon sword? As it turned out I was. A serrated blade is great for dispatching ones enemies, not so much when trying to cut wood however. Yep, within 5 mm of starting a cut, the saw started to bind. The teeth were now cutting a slot narrower than the plate.

Every downward spiral has a point where it becomes a vertical free-fall. This was that point. Realising I now had no saw that would work, and not owning a setting tool I realised that with nothing left to loose, it was MacGyver time!

Getting out my centre punch, I started the task of running down each side of the saw plate, and punching every second tooth. To be hones I really had no idea if I was salvaging my saw at this point, or just making noise for no purpose.

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Once that was done, running my fingers down the side of the saw suggested that I had indeed introduced some set back into the teeth. Highly inconsistent no doubt, but there was some set. Back to the test piece.

To say I was astonished at the result would be under selling my reaction. This thing cut very nicely as long as I stayed within the front 60% of the blade. There was a horrid tooth that was projecting way out (you can see the results on the image below, with the cuts on the far right showing that errant tooth leaving its mark. Trying to knock it back into place simply snapped it off, but at least I can now use the whole length again. Now I should point out that I consider this a monumental fluke and “phew” moment. There was no skill involved, just blind luck. And I only have a temporary solution. I suspect this is a temporary state of my saw’s terminal lucidity. I doubt it will work well for very long.

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There is however good to come out of this. I now have a saw that is in dire need of work, so plan to cut off the hardened teeth, and follow the process of filing in new teeth from scratch as a learning process (unless someone tells me that’s a dumb idea). If that goes reasonably well, I’ll progress on to making my own saw from scratch. So my emotional state went from anticipation to devastation to find a resting place at excitement.

Lance

Nothing like hands on learning and as you say when you get a decent saw you will have to sharpen and set it at some stage. I am surprised the hardened teeth did not all break off. I have heard of people using those blades with the hard teeth cut off to make another saw but have not tried it myself. I do have an old one laying about someplace and may try one day. Like your's was it's horribly over set. Always thought of the waste chucking those things away.
Regards
John

Lance, I think you're about to become a saw-maker! :D

Indeed, there's nowt wrong with the steel of the hard-points. As far as I can discover, the material they use for most hard-point saws is equivalent to 1080, and tempered the same as regular saw material. I've repurposed quite a few old HPs, and I couldn't pick any differences between the plate from these & stuff bought as 'genuine' saw plate. About the only difference is the rough finish on the cheap saws, but a bit of W&D and a good dash of elbow grease & you can polish the steel up to a near-mirror finish if you're so inclined.

So once you slice the hardened teeth off you can make a perfectly functional saw from it. The hardening only extends as far as the blueing, which is barely more than the bottoms of the gullets. Just put it between two bits of straight steel to act as a guide & heat-sink, & whizz the teeth off with a 1mm cutoff wheel in your angle grinder. Running a file over the cut edge will immediately tell you if you've removed all if the hard stuff.

For my first few saws, I was nervous about cutting teeth, so I took my blanks to a saw-sharpening place & they cut them in for me for a very reasonable fee (no setting or sharpening). Once you get the courage to make your own fangs, the next discovery you'll make is the poor quality of many saw files. There's a 'sticky' on the top of the hand-tools page with the 'great file test' results, that you might find wort reading. It's getting a bit dated now; there was a more recent thread on saw files that you'll turn up with a search, & it seems a few makers are beginning to realise they need to sell files that are fit for purpose if they wish to remain in business.

No turning back now, you are on the slippery slope & gaining speed....
Cheers,

Thanks Ian. I have tomorrow off, so in preparation I’ve already bookmarked an article you wrote for Aus Wood Review (I think) which demonstrates the cutting of the plate.

Thanks for confirming that the plate should be suitable. If it turns out nicely I will indeed polish it up, and make a nice handle for it. I believe Adam has a set tool, so may be knocking on his door in the near future.

Regarding the files, thanks for the pointer. I must admit that trying to work out what files I need has been a real struggle when you know nothing. Even the flat types, so many terms I have no idea what they mean. There a a couple of local outlets that are listed as Pherd file distributors, so will try them as I believe they make good stuff.

I’ll keep you all posted.

Lance

Lance

That's a good yarn and nowhere near as disastrous as I was expecting. Just the fact that you did what you did means that you have the courage to "go for it."

Consequently I fully expect that you will take up Ian's suggestion, which is both viable and cheap. I can't really add anything sensible to his comments other than suggesting you make up a new handle to go with it. There are plenty of patterns from which to choose: Just pick one you like.

This might assist:

https://www.tgiag.com/saw-handle-scans.html

The saw screws might be an issue. You could use the screws from the abomination the OEM intended you to hold the saw by, but a better option would be to find the traditional glover pattern saw screws, possibly salvaged from another damaged saw. Good luck with all this. It will be very worthwhile and we expect to see the results posted here along with another entertaining story.

Regards
Paul

Ps: It is always so refreshing to welcome another addict.

Just seen your post from while I was typing. All reference to Bahco can easily be removed with W & D paper and a suitable lubricant. WD40, turps or water (don't leave water on the blade for any length of time. It has to be dried off) can be used. Wrap the W & D around a small block of wood. I use a plywood board under the blade and possibly paper or cardboard under that as it can get messy. Try to avoid doing this on the kitchen table unless SWMBO is away for a considerable period of time. Start with 240g and work up to whatever you want. Most of the work is done with the 240g: The rest is just polishing.

Regards
Paul

Hi Lance, if you mean the article AWR recently made available online, it's been edited down a bit from the original printed version, but I hope you will get a few helpful ideas from it. Making a saw is not as difficult as it seems before you do it - go for it.

WRT saw files, Pferd are considered one of the better brands, but have been wildly variable in the recent past. Bahco are usually ok, but I've had duds in that brand, too. Neither is available at your local hardware stores, & if the 'distributors' near you are like the ones I was referred to up here, you'll have to buy 10 of each size, which you may not wish to do at his stage of your career. However, both brands are easy enough to find online, which is what I've taken to doing - the prices are in line with what I was paying at the distributors, & it's more convenient. New Nicholsons are said to be much better than they were a few years ago, too.

If you are near a Blackwoods, they sell P & N files which I've found to be pretty good, but the range of sizes suitable for saws that Blackwoods carry is pretty limited.

If you are only sharpening, not-so-good files aren't quite as irritating as they are if you try to cut teeth from scratch, that really sorts out the sheep from the goats.

Cheers,

Quote:

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Originally Posted by Bushmiller

There are plenty of patterns from which to choose: Just pick one you like.

This might assist:

https://www.tgiag.com/saw-handle-scans.html

---

Wow! What a resource. I was thinking I’d need to grab some photos of old saws on eBay and make a plan, but that resource is outstanding.

Lance

Lance

You may also find this interesting. One of the many Paul Sellers videos. This deals with removing existing teeth and filing in new teeth. His method of using a hacksaw to make the initial cut before shaping the teeth is good as it minimises the wear on the corners of the file. The file will last a lot longer:

https://www.youtube.com/watch?v=mTqZTGPPRj0

He files off the old teeth, which works well enough if you want to cut in the same number of new teeth as you can leave the barest hint of a tooth and that becomes your mark for the new tooth. However this probably will not work so well for you as you have to remove all trace of the induction hardened tooth and return to "normal" steel. Also Ian's suggestion of using a thin cutting disc on an angle grinder works extremely well and is very fast. Otherwise the Seller's technique has a lot going for it. Somewhere I have also seen him use hacksaw blades hammered onto a piece of soft wood to mark the ppi. An 18ppi blade can be 18ppi or 9ppi of course. I am sure you can understand the principle. A 12ppi or 13ppi tenon saw is very good all round pitch.

There are also tooth templates about and while I have used them I think I prefer the Sellers methods.

Blackburn Tools - Saw tooth spacing templates

Regards
Paul

Quote:

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Originally Posted by Bushmiller

You may also find this interesting. One of the many Paul Sellers videos. This deals with removing existing teeth and filing in new teeth.

---

Thanks Paul. I had actually watched that over the weekend and thought it was a comprehensive, and dare I say it, fool proof method for me to follow.

I spent several hours reading the sticky on saw sharpening last night following Ian pointing it out, and the corresponding PDF of the file research. I think I'm more confused than I was before... but files aren't that expensive, so if I get the wrong thing it's not the end of the world. A quick question though, I'm assuming that whilst I need a single cut file for the teeth, I can use any file for the flat as it's only really prepping the saw plate before I add the teeth?

I will go and visit some outlets this morning to see if anyone stocks what I need, otherwise I'll have to do an online order and wait.

Lance

Lance

The double cut files don't produce such a fine finish as single cut but I would not be that concerned either way. A good double cut file is infinitely preferable to a poor single cut for instance. Also if you are able to get both you could consider using the double cut file for shaping the new teeth and then sharpening with the single cut. I really would not stress too much over this aspect. I am assuming you are looking at 12/13ppi for a cross cut saw or, say, 10ppi if you wanted a rip saw So you are chasing 4" or 5" files respectively both in DEST (Double Extra Slim taper).

For jointing (as opposed to filing off the teeth) I would go with a smooth file probably, but a lot depends on what length file you use. Smooth would be good with 10"/12" files but in shorter lengths a 2nd cut file might be good too. Having said that, whatever you have lying in in the tool box will be satisfactory for your purposes.

Lastly I would add that all of us are speaking "ideally" and you may not be able to easily source the exact file. Just do the best you can as one or two lengths out or one or two tapers out will still produce a respectable result: Just not as good as it could be. Coarser teeth are more forgiving with regard to file size than tiny teeth. Tiny teeth being the dovetail sizes finer than 12ppi.

Regards
Paul

Lance,
A fantastic story I really enjoyed reading your antics in regard to becoming a saw sharpen an for I assume will be followed shortly by saw maker.
Honestly like a lot of stuff the first step is the biggest.

Just start the rest will all happen an welcome to a very dark little corner of the forum but very nice little place.
Not sure if there’s something in the waters in Tasmania at present but seems a lot of interest in hand saws.
BTW im pretty confident Adam down the road from you has a saw setting tool.[emoji6]

Cheers Matt.

It was a busy day today. I popped into Nubco (a local trade supplier) who had several Pferd saw files. I think they were all a little big, but got the smallest one they had.

First things first I undressed the saw so that the surgeon had ready access to all the bits as required.

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It was now time to trim some excess flesh from the saw. Using Ian's technique, I clamped the blade between two pieces of angle iron, and used a 1 mm cut-off wheel on my angle grinder. The angle was a little large though, so had to angle the cutting wheel to get to the saw plate. This made a bit of a mess. I tried cleaning it up with a file, but that would take a long time, so put a flap disk on my angle grinder, and raised the plate just proud of the angle iron and used it as a fence. This got the saw plate edge beautifully straight, and with a lovely polished edge to boot! And before anyone asks, no, I didn't use my spirit level to grind against, it was the only way I could get a good contrasting background (I guess that's why SBS uses yellow subtitles).

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At this point I thought I'd may as well give the plate a clean up. I didn't know if I'd have a workable saw afterwards, but also assuming that if I did, I'd not want to be messing with W&D after I'd sharpened it. As such I hedged my bets and cleaned it up with 240 W&D, but didn't bother with polishing.

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Now onto preparing the teeth. I used the Paul Sellers' method lined by Paul a couple of posts ago. I thought I'd be clever and use some skirting board profile to make the guide from. The only problem was that being Tas Oak, it's a bit splintery, and the narrow edge was damaged quite easily (I won't be able to use it again). I'll make another one from spotted gum, which should offer some more longevity. The other mistake I made was to use a hacksaw blade to mark my guide. I will use a ruler the next time. It was hard to be accurate with the hacksaw blade marks. I prepared a new hacksaw blade by grinding off the front teeth, and "ramping up" to the full teeth as described and set about cutting the notches in the plate. I was surprised how well this worked. My notches were a near exact match to my template.

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I was now up to the stage I was dreading; filing the teeth. Disregarding the fact that the first two teeth are backwards :doh:, it went very well, and before I was half way though, I was actually enjoying myself. All that worry for nothing. I set up a low light behind the plate so that the flat facets on the top of the teeth were obvious. Without the light proved near impossible to gauge my progress. the photo below is from my first pass, before I went over them again. After that it was time for my saw to get dressed again, so that I could take it for a test run.

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The result? Well it certainly cuts better than it ever has. The kerf is nice and narrow, and ti cuts straight, but then I guess you'd expect that with no set. There is one section about half way down the plate where it resists. As in the cut goes smooth-catch/drag-smooth. I've looked, tried to re-shape the teeth to be more uniform etc, but just can't get rid of the drag. I've run the block of W&D down both sides to make sure there weren't any burs that were catching. Nothing. I've added a photo of the troublesome area in case someone else can identify the issue.

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So how do I feel at the end of the day? I feel like saw sharpening has been demystified. I'm rubbish at it right now (some teeth look like they've come direct from an old hag's mouth), but am keen to work at it and get better. I'll do some more reading over the coming days and perhaps have another go at jointing and re-sharpening.

Next up, make a nicer handle, and find a tool to set the teeth a little. I don't know that i'm quite at the saw-with-no-set skill level :) .

Lance

Strewth, you're a tiger, Lance, there's no stopping you once you get the bit between your teeth! :U

Couple of comments - as you realise now, a strip of flat plate makes a better guide than angle - you can get at the piece you're cutting a lot easier. However, you solved the problem with a bit of ingenuity & effort. You're a natural at this game.

I'd say the 'drag' is likely to be a couple of high teeth in the area indicated. There is no really reliable method of picking which teeth are high at this stage, unless you have microscopic eyes. Laying a straight-edge along the tops is nigh on impossible, you just can't hold it while you check each tooth top. If you use the saw for a while, you may find it settles as the high teeth wear down quickly (saw a few chunks of the hardest wood you have lying around & that will speed the process up). After a bit, you may see a few teeth develop shiny tops - they were the high ones.

The most foolproof method is to joint the teeth, then you will clearly see which ones were out of whack by the broader flats on the tops. Re-form the teeth, paying attention to the gullets either side of the flat tops. One is usually obviously shallow, but sometimes it may be both. The shallow gullet is the one that needs deepening, but you have to lean on the file so it only cuts on the side with the broad top. Hard to explain in words, but I'm sure you'll figure it out.

Ya gotta get yerself a setting tool, saws just don't work proper without set. Yes, I know, there are saws that run without set, but the blades are tapered and the teeth are sharpened very differently. We'll leave that subject for saw-making 102.

You are going well - the slope has just inclined a bit more.....
:D
Cheers,

On the saw binding, I don't know if it is just the pic, but the gullets look higher in the highlighted area. Difficult to tell with photographs. Also is the plate still perfectly straight? A slight "lump" could also cause the grabbing particularly without any set to the teeth.

Regards
Paul