Thread: How should I restore this saw?

Originally Posted by snafuspyramid

....My first question is: can I do anything about this pitting, like sanding back that part of the blade? It's not especially deep, and although I would be reducing the width of the sawplate in those areas somewhat I believe there'd still be a good deal to spare. ...

Eddie - looks like quite a nicee little saw. I wouldn't try to do anything more than you've done. You could try some wet & dry pper to get a bit of a polish on the blade, but from experience, your arm will drop off before you sand out that pitting. Apart from being unsightly, it won't have a huge impact on the function.

Originally Posted by snafuspyramid

.....My second question is: how can I refinish the handle? It looks like apple wood, but is covered in dirt and very fine flecks of red paint (I think). I was planning to sand it back very lightly, with fine sandpaper - really just to clean it - then clean it with some turpentine and finish with eight or nine coats of pure tung oil (thinned with a little citrus terpene), covered with Renaissance wax. Obviously this finishing method takes a solid few weeks. Will that do the trick? I don't want to use shellac, as I don't think it will stand up to the abuse. Obviously poly/varnish would be blasphemous. I want the tool to look old (because it is), but I still want it to be clean, hydrated and protected....

I would use some fine steel wool & paste wax and jst give it a good clean & polish. That will preserve most of the patina, and you may be happy with leaving it as-is after that. Shellac is actually quite durable on handles if not overdone, but waxing followed by regular use & 'palm grease' will make it look pretty good after a while.

Originally Posted by snafuspyramid

...Thirdly: what's the best way of cleaning the brass nuts? (They've been partly removed in the photo). ...

Fine steel wool: oooo steel wool will give brass a matte sheen, & if you want a high shine, buff with jeweller's rouge on a cloth or felt wheel, or use "brasso" if you don't have a buffing wheel. If the surface is badly marked & dented, you may need to start with fine sandpaper.

Originally Posted by snafuspyramid

Fourth: what's up with the sawplate? From what I can gather the advantage of having a sloped tooth line (sloping up towards the toe) is that it counteracts what would otherwise be the effect of having a handle at that angle, i.e. far too much rake. Does that make sense? {EDIT: That's not right. It actually increases the effective rake angle!} Also, I can't find any reference that mentions a Disston backsaw tapered in this way...

There has been much argument & discussion about canted blades (which seems to be the currently-agreed term amongst the debaters). Some saws were definitely made that way, but just why, no-one knows. I've made quite a few canted small saws, just because I like the look. The other school of thought is that canting tends to happen over time as people joint & sharpen the teeth, The teeth at the toe end get worn & beaten up most, and in cleaning them up, you take a fraction more off the toe than the heel. Over years of use, the toe end of the saw becomes narrower than the heel.
Canting does not have any practical effect on rake angle - that is relative to the tooth-line itself. It does alter the hang-angle a little, but probably not enough to make any practical difference....

Cheers,

Rake angle is the angle of the face of the tooth measured from a perpendicular off of the toothline, this is not effected by the back or the handle.
Hang is how the handle is attached relative to the toothline and is not effected by the back. Some saws aren't really canted at all, the spine is just driven farther down on the plate at the toe than it needs to be, or originally was. You have a nice little saw, When I clean them up I just sand off the plate dry with 100 grit paper to remove the coarse rust and finer grits until I get the polish I want. If the saw has an etch I avoid that with the coarser paper. If the pitting is shallow you can sand it out a bit, then sharpen and set. The saw should work fine unless the plate is rusted too thin.

Originally Posted by IanW

Canting does not have any practical effect on rake angle - that is relative to the tooth-line itself. It does alter the hang-angle a little, but probably not enough to make any practical difference....

Cheers,

Yes you're right, sorry, I meant hang angle. As I understand it rake angle is a matter of tooth geometry whereas hang angle is the angle at which the handle directs force into the sawplate, or the "line of thrust".

Following this discussion I'm tossing up whether to sand the blade back a little and get a bit of a polish. It occurred to me that, since this will be filed traditional rip cut, the pitting doesn't really matter, because there is no need for a sharp bevelled slicing edge. I also rather like the dull, irregular grey finish that is left behind on old tools once the rust is gone - I think that old tools look best when allowed to age with dignity. I'm not sure that I understand the need to have a polished blade - my three Japanese saws are polished as heck but that doesn't help me much! I think the blade just needs to be smooth.

However, I want the tool to be as functional as possible. When I run a finger along the tooth line it's very easy to feel where the pits are, they're quite rough. I worry that, even with a few coats of wax and a spritz of camellia oil, those patches would slow down the saw in the cut and be a hassle. There is also the propensity for them to rust. So much as I am loathe to lose the original finish, I wonder whether I might be better off stripping it all back.

As far as the back goes, I'm pretty sure that it must have been inadvertently forced further up into the spine at some point. The saw has apparently lived its entire life at a farm out near Bairnsdale, so I think the chances of the plate having been simply worn down by use are pretty slim. I'd think different if it were from a cabinet maker's estate or similar, although of course I'm just guessing. You'd need to have Herculean strength to achieve this effect just by sawing with it. What's more likely is that it was dropped or crushed at some stage. If it's anything like the tools at my parents' property, it's more likely to have been used as a hammer than a saw.

Then again, there seem to be too many vintage dovetail saws with this "problem". Seems mighty strange. Does anyone know of Disston actually selling blades of this type?

You have quite a bit of fine surface pitting as well. I like to polish up the plate as best I can as a smoother plate will have less friction in the cut. some of that can be corrected by putting in more set. A polished blade allows the user to look in the reflection of the plate to aid in cutting 90 and 45 degree angles across the stock by eye and to check to see you are sawing square down the stock as well.
Mike

I second what Mike says - a clean blade works more smoothly in most woods. But I only go to about 400 grit max for an old saw, & don't bother with mirror finishes, partly because I've never been able to use the reflection business to any advantage in my work - a squared scribe-line takes but a second or two to apply & is far more reliable in my hands. For non-critical cuts I can judge square to within a degree or three, but I won't take any bets on a 45 degree cut!

Edit: I just re-looked at the pics and you do have a lot of pitting, which I doubt will come out to any great degree unless you sand it to blazes. A small pit coming on the edge of a few teeth won't affect performance noticeably, but if there are too many, you will have a lot of teeth not cutting their full width. Your old lady needs a bit of TLC on those fangs, too - thay are all over the place for rake angle, and to my eye, have been sharpened with too large a file size, causing more gullet than tooth. But those issues are easily fixed!
Cheers,

I hadn't read this before now, but RayG is on the case ... Canted Blades

Plenty of brass-backs in particular online are canted.

I don't know if pits encourage rust .. except by physically trapping new dust. Black rust is stable and protective I believe ... you can use phosphoric acid and a toothbrush to convert red rust ... or something from Bunnies etc.

If it cuts anywhere near reasonably, try it on some soft then hard wood and see what rubs off and what doesn't. If it doesn't cut well, make a thinner kerf with one of your japanese saws and work it down into that.

My gateway-drug first nice handsaw has some large pitting and I love it very much. The rust was over many teeth and came off via using it to reveal surprisingly good shape.

Cheers,
Paul

DSCF9036[1].jpg

Cripes Paul, now my saw doesn't look so pitted after all.

Well I assaulted the blade with sandpaper again for a while. Didn't do much. Gave the whole thing a good coating of wax, which makes it feel a lot smoother, but still a bit crunchy where the pitting is. I've included photos of both sides of the saw so it's clear exactly how much is affected by the pitting (not much).

Not much more I can do about the pitting, I've decided, so I'll just leave it. I'm wondering, though, whether I could fill it up with Renaissance wax - that stuff dries truly rock hard - so I can get a smooth surface with it.

I tried to resist the urge to give the handle a coat of tung oil, but it... just... looked... so... thirsty. Despite being such a dense wood it drank up a remarkable amount of the oil, and seems a lot happier for it (at the risk of, um, anthropomorphising). Before applying the oil I cleaned it up with turps and fine steel wool. I left all the imperfections and tiny paint splatters - I've decided I like them. If I finish the handle any further it'll be based on this.

The wood looks very dark in the picture, but it's just had the oil put on - it'll lighten up very close to its original colour by tomorrow. I'm still tossing up suggestions for finishing. I can either just wax it following Ian's suggestion, or apply BLO or tung in a large number of very fine coats (how I finish my other tools), or maybe shellac after all. I do want it a bit shinier...

Finally, I've noticed that there is a distinct wobble where the handle meets the blade. How can I fix this?

Originally Posted by snafuspyramid

Not much more I can do about the pitting, I've decided, so I'll just leave it. I'm wondering, though, whether I could fill it up with Renaissance wax - that stuff dries truly rock hard - so I can get a smooth surface with it.

Eddie, if it were mine, I would just leave it be. If the rust patch is 'catching', that implies something is still sticking out beyond the surface of the plate. If so, a little more light sanding to make sure any original surface is level should fix that - holes (pits) shouldn't catch. It seems more likely to me that there is some roughness of the teeth in that area, which may either smooth out with a bit of use, or respond to a few more jointings & sharpenings. While I've never used renaissance wax, I can't imagine many substances that would stick well enough over time to bother with, but oth, I can't see how it would do any harm, so try it & see what happens. Best way to find out is to experiment!

Originally Posted by snafuspyramid

Finally, I've noticed that there is a distinct wobble where the handle meets the blade. How can I fix this?

Sounds like you have some loose/worn bolts. I assume you would have already tried tightening them if there is a slot on one side - doesn't always work on old wood because the 'shoulders' on the other side, which are meant to prevent rotation of the bolt, are often just teeny nubbins and they soon twist the wood fibres off in old wood, if the threads are stuck, as they usually are. Then it is usually exceedingly difficult to find a non-damaging way of holding the bolt head while you twist the opposite side. If they are rivets & not bolts, the only recourse is to hammer them (with great care). Or you could replace the bolts with ones that can be tightened (something I would be reluctant to do on a precious oldie, but not on a user). Or just live with a slightly wobbly handle, but that is intensely annoying to me, so I presume it is to others....

Cheers,

Originally Posted by snafuspyramid

Not much more I can do about the pitting, I've decided, so I'll just leave it. I'm wondering, though, whether I could fill it up with Renaissance wax - that stuff dries truly rock hard - so I can get a smooth surface with it.

Eddie, if it were mine, I would just leave it be. If the rust patch is 'catching', that implies something is still sticking out beyond the surface of the plate. If so, a little more light sanding to make sure any original surface is level should fix that - holes (pits) shouldn't catch. It seems more likely to me that there is some roughness of the teeth in that area, which may either smooth out with a bit of use, or respond to a few more jointings & sharpenings. While I've never used renaissance wax, I can't imagine many substances that would stick well enough over time to bother with, but oth, I can't see how it would do any harm, so try it & see what happens. Best way to find out is to experiment!

Originally Posted by snafuspyramid

Finally, I've noticed that there is a distinct wobble where the handle meets the blade. How can I fix this?

Sounds like you have some loose/worn bolts. I assume you would have already tried tightening them if there is a slot on one side - doesn't always work on old wood because the 'shoulders' on the other side, which are meant to prevent rotation of the bolt, are often just teeny nubbins and they soon twist the wood fibres off in old wood, if the threads are stuck, as they usually are. In which case it is exceedingly difficult to find a non-damaging way of holding the bolt head while you twist the opposite side. If they are rivets & not bolts, the only recourse is to hammer them (with great care). Or you could replace the bolts with ones that can be tightened (something I would be reluctant to do on a precious oldie, but not on a user). Or just live with a slightly wobbly handle, but that is intensely annoying to me, so I presume it is to others....

Edit: I just looked back at your original pics & it looks like it has split nuts, so if you haven't got one already, make yourself a split-nut driver (easiest thing is to file a slot out of a cheap straight-blade driver of the right size). You may still have the problem of the bolt turning, but you could be lucky.

Cheers,

This canting thing is a puzzle all right ...

On the one hand you have ...

cant backsaw 002 (Large).jpg

and yet ...

cant backsaw 004 (Large).jpg

The front (vertical) edge of the blades of the canted saws are at an angle to the back also, so I am thinking that if it was due to sharpening unevenly then the front edge would still be perpendicular to the back like the second three saws.

I remember now I did suggest some time ago that by cutting blades out non-rectangular-ly you might get a little more mileage out of a given amount of blank sheet steel. Although in that case I can't see why you wouldn't mark out and cut so the front edge sat square just like a "normal" saw.

!!

- - -
Regarding finishing the handle I will look forward to seeing what you do. I have only put coats of BLO on a #2 handle I repaired ... that was a few months ago ... and it still feels silky, but it looks matt like yours.

Cheers,
Paul

Originally Posted by IanW

Or you could replace the bolts with ones that can be tightened (something I would be reluctant to do on a precious oldie, but not on a user). Or just live with a slightly wobbly handle, but that is intensely annoying to me, so I presume it is to others....
Cheers,

I saw via the metal forum that shim metal is available in 1-6 thou quite cheaply ... I guess a "bushy's solution" might be to knock something in alongside the blade to take up the slack ... if the nuts were a problem.

I know someone trying to rehab their handsaw in the forum here was having all sorts of problems with his nuts.

Age-related I suppose.

Paul

Originally Posted by pmcgee

.....The front (vertical) edge of the blades of the canted saws are at an angle to the back also, so I am thinking that if it was due to sharpening unevenly then the front edge would still be perpendicular to the back like the second three saws.

I remember now I did suggest some time ago that by cutting blades out non-rectangular-ly you might get a little more mileage out of a given amount of blank sheet steel. Although in that case I can't see why you wouldn't mark out and cut so the front edge sat square just like a "normal" saw.

Paul - there have been convincing arguments backed up with catalogue pics that put beyond doubt that saws were made 'canted'. I can also vouch from experience that it's not hard to produce canting, over a long time. When jointing, it nearly always takes a few extra swipes at the toe end to produce even flats - not much, but it will add-up over the years. Your point about the toe being perpendicular to the tooth line is a very good point, & should be helpful in deciding how a particular saw started life. One would assume the toe would be made perpendicular on parallel & canted blades alike, for appearance (I keep mine that way), but perhaps not always, since it depends on how you view it, & even a canted blade will lose more at the front over many sharpenings. The change in angle is so small that it is rather hard to eyeball...

AFAIK, no-one has come up with any practical reasons for canted blades, other than the possible saving of metal as you (& others) have suggested. I have done just that myself, & squeezed a couple more blades out of a remaining piece of plate, when making parallel blades would have yielded just one 'normal' blade, and one very under-nourished blade. In fact, there is a slight dis-advantage in a canted blade, since it will wear down to the point where the spine limits depth of cut a little sooner, but the difference is minor, & unlikely to worry the first (or second) owner of the saw! My considered opinion is that it was done purely for aesthetics. I like the look, but p'raps it's not to everyone's taste, hence saws were made both ways to keep us all happy little vegemites....

Cheers,

i wouldn't worry about the pitting at all on that saw, its only effecting two teeth by the looks on one side in the middle and maybe two or three on the other near the handle, thats how it looks in the pic to me at any rate , as you re-sharpen and loose more plate (1/2 inch or more) some more teeth might be affected but thats a long way off. also i wouldnt worry about the pitting effecting smoothness through the timber, it should have next to zero effect, if that, the old patina looks good imo opinion too. now and again i hear others make that suggestion (so not singling anyone out in this thread or forum) but from my pov dont be concerned with needing or using reflections (from a shiny plate) to assist in cutting square, your making a rod for your own back or a crutch you need to lean on, you will do (develop) far better without using that method, i think that method was spouted to sell new saws instead of purchasing second hand saws, nothing more..perhaps some academic who majored in geometry saw some value in it

with the split nuts, dont try and simply (but significantly) tighten them, they are only brass and you have a very good chance of damaging the threads or even breaking them off (split nuts especially! edit; now i notice yours are not the split nuts which are a bit tougher), use a couple of bits of timber or ply and clamp the handle together to close any gap that might be there, then the nuts can be tightened without putting as much strain on them (use something to free the threads up first if split nuts), this method can also assist with getting stubborn nuts apart.

dont ever use a saw when the handle is partly loose or has small wobble, fix it! they only get worse and you can damage the nuts/bolts entirely, sometimes the handle a bit too and occasionally the saw plate, if its a show or conversation piece then retire it (assuming you cant fix it without alteration), if its to be used and if the nuts need replacing thats whats needed (just be sure to give it good thought first), on a few occasions (just a few) you might be able to find a work around to repair holes in the handle or beef up the brass screws, some of that hollow brass tubing from hobbie shops can work if you get a good fit over the screws.


Ian, i'll weigh in on the tapered back saws (aka canted),

there are a few good (practical) reasons for tapered blades ! , they feel more balanced (thats actually an important reason imo) but is more noticeable the larger the tenon saw gets, obviously everything has diminishing returns as they get smaller in size, but it is still there (so if your an old manufacture making a premium saw you might want your whole range to have the feature). it also benefits for the same reasons a full size saw is tapered (not to be confused with 'ground tapering' which is the gauge/thickness of steel) and that is it adds strength to the blade and directs the forces to the handle, when the blade is rectangular the strength gets dispersed to places you dont want..in normal terms of usage it means the tenon/back/dovetail saw is stronger/stiffer and thats what their function is all about, also they seem to track better too ..they also have other benefits, whether thats why they were made that way i couldnt say (egg/chicken) but tapered back saws have an efficient cut angle and when lifting the back to horizontal also assures you of not cutting beyond the line on the unseen side, which helps in not blowing out or chipping the wrong side of your timber, controled to the end of cut you might say.

some mention has been made about saving metal plate, perhaps i have got it wrong and no doubt you guys have it all worked out , perhaps only from a manufacturing perspective though, it occurs to me it would take more steel to make tapered blade, e.g. from a carpenter, joiner and cabinetmakers perspective, as I choose a saw, the plate width is a major factor to suit the intended purpose, i dont look at the widest (at handle) width of plate and choose, i look at the smallest dimension and choose, hence if i need, say 3 inch, whatever, i look at the toe on a tapered back saw for its minimum clearance, more modern (which still means old to us) or contemporary back saw manufactures saved money imo by going to parallel blades, we loose out, not them...whilst i wouldn't disagree that many old saws might have been filed to un-intentionaly produce a tapered/canted saw plate, imo its pretty easy to keep it level and straight, i could easily give argument that many saws are jointed evenly or close to it (or should be), one thing i am absolutely sure of, and i suspect joiners were the same no matter how long ago, is they get very p#$% off iff someone sharpens their saw (in the old days often a nominated person) and loses saw plate or alters the shape/angle, e.g one might () be known to measure exactly saw plate dimensions before sharpening and after and go the royal crazy if someone had filed away more than they should have or perhaps more importantly changed the tooth angle in relation to the handle, no one wants their saw to be radically different (and everyone knows it starts with small inaccuracies) ,assuming they like it. imo its relatively easy to sharpen without loosing extra from the front, many saws arnt worn significantly right at the tip anyway, evenly jointing should take care of it


cheers
chippy

Originally Posted by snafuspyramid

Finally, I've noticed that there is a distinct wobble where the handle meets the blade. How can I fix this?

Depends, most likely you've tried tightening the screws, If that's not working, then .. read on ...

Check to see if the screws are bottoming out, you've already got the screws out, so just file a bit off the "nut" part, it's really a tube with thread on the inside, and you just file the tube a little shorter.

On the other hand, sometimes you don't want to remove the screws, say for example you want to keep everything as original as possible
Then you can soak the handle in something to cause it to swell a little then the screws will grab.

The reason the screws came loose in the first place is seasonal humidity variations, when the humidity is high the wood swells and compresses irreversibly against the screws, then when the humidity later drops the blade becomes loose.

You can tell a saw that's been in consistent use for a long time, the screws gradually sink into the wood. Each time the blade becomes loose the screws get tightened and slowly sink deeper..

In the case of the Disston/Glover's "Improved Screws" there is a limit to how far this adjustment can go. Glover's patent US Patent: 375,350 - Glover's Saw Screw



Regards
Ray