Ever get a saw you couldn't file?

[David Weaver]

I got a disston #7 this past week, I figured it'd be a good saw for me to cut down into a panel saw - 10 points crosscut and 26" long, lots of plate, plenty to cut down and file in another nib.

So I got it out, and it felt like ice when I was trying to joint it, dinged up the bastard file I used to joint it. It can be filed on the very ends, but in the middle, nothing - file won't touch it. If you insist on ruining the file, the saw and the file are a pretty close contest regarding which is tougher, ruined a simonds saw file instantly.

Has anyone ever seen that? The plate is pit free, but has a varnished look or tempered color and some staining, same straw color you'd have if you tempered steel by color. I can't see any etch on the plate to confirm that it's actually a #7.

Contemplating a diamond three-square machinists file to sharpen it and then use it, anyway if I can manage to get it sharpened. It sure wouldn't wear quickly.

[harry strasil]

Only time I ever came close to what you have is a HD nail saw, thick plate, 14 tpi, no fleam, no set.

http://img.photobucket.com/albums/v81/irnsrgn/wood/nailsaw.jpg

[george wilson]

You will probably also ruin the diamond file. The diamonds will most likely become dislodged before you do more than a few teeth.

File only very lightly with any diamond product. The narrow width of the saw teeth will hasten the diamonds coming loose.

[harry strasil]

If you are lucky enough to find a file from long ago, the files from the past were made of about 10104 or what they called 104 points of carbon, the newer files may be 1095, if you can find a supplier of industrial files, they often are 10100 the same as timken bearing races.

[george wilson]

Actually,David,if the saw is that hard,you will break off the teeth trying to set them. I think it might be best to not use it at all If I HAD to sharpen it,I'd dress a grinding wheel to tooth form,and make a jig to evenly GRIND the teeth. No cure for setting a saw that hard,though.

[Roger Davis IN]

Is it something like a Disston No. 240? That one was filed rip, but was made (and marked as) for cutting metal. I think the metal cutting saws were heavily tapered and used without set (IIRC).

[Marv Werner]

David,

You might try a new double cut file and bare down hard on it as you file. You have to force it to cut. Make sure the gullets are just barely clear of the vise jaws. You need a vise that clamps the blade tight and even. You don't want any vibration going on.

You might end up with a saw with zero set. Do the teeth look as if they have set in them now? If so, when you reset them, make sure you set them in the same direction they are now set and give them very little set.

Before you set them though, hold the blade in the light just right so you can sight down the side of the blade from top to bottom so you can see if the teeth protrude out from the blade at all. Do this on both sides. If there is some set and they look to be the same on both sides, leave them as they are and just lightly side joint both sides. Then do a test cut.

Marv

[george wilson]

I HOPE David doesn't BARE down on the saw!! I assume he's wearing clothes while doing it!:)

[Marv Werner]

I'm going to take that as a joke, I just hope David does too....:D

[David Weaver]

David,

You might try a new double cut file and bare down hard on it as you file. You have to force it to cut. Make sure the gullets are just barely clear of the vise jaws. You need a vise that clamps the blade tight and even. You don't want any vibration going on.

You might end up with a saw with zero set. Do the teeth look as if they have set in them now? If so, when you reset them, make sure you set them in the same direction they are now set and give them very little set.

Before you set them though, hold the blade in the light just right so you can sight down the side of the blade from top to bottom so you can see if the teeth protrude out from the blade at all. Do this on both sides. If there is some set and they look to be the same on both sides, leave them as they are and just lightly side joint both sides. Then do a test cut.

Marv

They have plenty of set. they look like they are as-from factory. Someone used the saw some and made it mildy dull. I'll bet they tried to sharpen the saw and set it aside.

I have some second-cut files that I've been wondering if I'll ever use them. I'll get them a shot at this.

I don't mind peculiarities, I guess, I just wish they were on someone else's dime and someone else's time :rolleyes:

The old sheffield saw I showed the other day is a hard saw, but it can be filed. I kind of expected it from that saw given its age, but for this one to be a lot harder than that yet, I didn't expect it!

Were disston saws breasted when new? This one is.

Whatever did the teeth last time (set and sharp) was a machine.

Might be an interesting exercise to anneal a worn out file, then file its teeth off and see if I can embed some 100 grit loose diamond in it and try it on this.

I really should just throw it away, but I paid what I'd consider to be a lot for a #7 with a tote that's in bad shape ($30) because it was a full plate and a tooth count that I wanted.

[harry strasil]

I never saw a saw saw, like that saw I saw saw down in Arkensaw.

[David Weaver]

I'm going to take that as a joke, I just hope David does too....:D

I can imagine explaining things at the hospital.

"Doc, they told me that I had to use this type of file in the buff and the saw slipped out of the vise....


... i swear."

[Marv Werner]

David,

Yes, the better saws were breasted from the factory, some as much as 3/8". Your saw being breasted, you will have to lower that area of the tooth line down lower in your vise so the gullets are barely above the vise jaws. Make sure your vise is sturdy and doesn't move as you force that file to cut. You mentioning the blade being breasted gives me a glue as to why it is harder to file in the middle area. The teeth are not being supported as well and are vibrating.

With the teeth having plenty of set, it should be relatively safe to reset them if you need to. Most saws I get, will usually have too much set.

Marv

[george wilson]

David,a fine cut file will cut harder steel than a coarse cut one. If you have been using a bastard file,a switch might be in order. IF that saw has been set without the teeth being broken,which you just revealed,perhaps it's your coarser file that is a problem.

Old new stock triangular files are among the easier type files to find. Keep a lookout for them. Harry has a point.

[Jonathan McCullough]

Can't really say I've run into a saw like that. I wonder if they didn't temper it correctly. Given the millions of saws they must have made, isn't it possible?

I try to not joint saws if I can avoid it, but when I do, I joint to get it flat, then do strokes forward starting at the middle and going toward the toe, then an inch forward of the middle and going toward the toe, then two inches from the middle, etc., repeat from the middle to the heel, etc. to get a little belly on the saw.

[David Weaver]

I've had some trouble finding NOS files.

Strangely enough, the one full box of NOS files that I have is a set of simonds red tang double cut 6 x-slim.

Not ideal for 9 tpi, but good enough.

I just ran downstairs, and as I mentioned above, there wasn't much wear on the teeth, they were just rounded some. The nicholson bastard file literally did nothing on them when jointing, though they ruined the file, or at least a part of it where it fits in my jointing block.

So, anyway, I just ruined one of the double cut files on the saw (all three sides), but it is sharp now. That file cut just well enough to bite into the saw plate for a few teeth. I didn't bother with the front 5 inches of teeth, who cares what they do, anyway. They are a tiny bit softer, but still very hard.

Thanks for the suggestions.

Marv - I have several saw vises, but I always file between two sprung boards in a large machinist vise. Obviously, they draw closed when I put vise tension on them, and they work far better than the cast iron saw vises I have in terms of even pressure and noise reduction, plus, I can scribe a couple of fleam angles on the edges of the boards with an angle gauge and not fiddle around with any other visual assistance - just check my hold angle against the choice lines as I'm going along.

I don't sharpen saws as well as darryl weir, but the worst I run against is a little fat tooth skinny tooth when doing crosscut saws that need a fair bit of work. That's really the only thing that still vexes me, though the problem is greatly reduced since I stopped flipping the saw in the vise to file the teeth that are set pointing toward me as i face the saw plate and made better use of visual aides, especially a tiny angle block on the end of the file.

[Jim Koepke]

I can imagine explaining things at the hospital.

"Doc, they told me that I had to use this type of file in the buff and the saw slipped out of the vise....


... i swear."

When the Doc asked me how I got in this condition, I said, "hey sawbones I'm just carrying on an old family tradition."

jtk

[george wilson]

Glad you got the fine cut file to work. It is a wrinkle worth remembering that a fine cut file will file harder steel than a coarse cut will.

The saws we made from 1095,and which,hopefully,small makers of premium saws also use,is much harder to file than any old saws I have encountered. It does tend to wear out files,but also stays sharper longer. It is 52 rockwell,and you have to be careful to not try to set the teeth too much on the thicker gauge saws,or you can break a tooth off.

The softest saws I ever filed were the Garlicks. I didn't try Lynx or all the other English made saws that are made today.

P.S.: you might try dipping your file in kerosene periodically when filing a hard saw.

[Marv Werner]

David,

Most old cast iron saw vise I have run across are quite inadequate when it comes to being sturdy enough to prevent vibration. The best one I've owned is a Disston 3D that I have overhauled so it will clamp tightly and evenly. I have even replaced the bench clamp with one that can be bolted to the bench. My main vise is a huge heavy duty Acme with 28" jaws.

Your method sounds like it is very solid and practical.

As for files..... most people on this side of the pond, when they can't find NOS files will buy Grobet. You can buy them from TFWW. I have so many NOS files, I've not had to by any yet, but when I do, they will be Grobet,s.

Marv

[Marv Werner]

Any taper file that is made for filing handsaw teeth is considered "fine" as compared to say medium or coarse.

A taper file that is "double cut" is one that has two lines of teeth cut in two directions diagonal to each other as apposed to a single cut file with only one line of teeth.

Any file can be "double cut" type, even large flat medium or coarse files.

Marv

[John Coloccia]

As for files..... most people on this side of the pond, when they can't find NOS files will buy Grobet. You can buy them from TFWW. I have so many NOS files, I've not had to by any yet, but when I do, they will be Grobet,s.

Marv

Yes, Grobet does make a nice file.

[David Weaver]

The softest saws I ever filed were the Garlicks. I didn't try Lynx or all the other English made saws that are made today.

P.S.: you might try dipping your file in kerosene periodically when filing a hard saw.

I can't remember what I tried to use as a lube a couple of times ago, but it wasn't kerosene. I think it might have been light mineral oil, which was way too heavy. I should've tried kerosene. Too much speed and pressure made smoke. Thanks for the tip.

I have filed a few dozen vintage saws, I guess. I don't know that I'd have ever said any were definitively harder than 1095 except for the sheffield saw I mentioned a couple of days (it's really hard, but not so much you can't file it), and this goofy saw we're discussing in this thread is miles harder. It has to have been a reject that got through. I don't understand how they set it - their machine setting tool must provide a lot of support to the tooth and plate. I'm not even going to begin to try to adjust the set on it.

A brand new single cut taper saw file literally skids on the 3/4ths of the teeth that are in the middle. If you persist with the file, it ruins all of the keenness on one tooth. :mad: If it weren't only slightly dull (the teeth were just barely rounded like a pinpoint amount), I would've thrown it away.

If some of my other vintage saws are harder than 1095 (i have two plates made with 1095), then it's tough to tell, i think a lot are close (some older #12s I have are file killers), but I also have plenty that yield to the file without much argument. I think 1095 is just about right. I don't reuse a cutting side of a file, anyway.

None of my saws are as soft or as thick as those garlick and sons new saws. I've gotten a couple of those euro-made saws and they are way too soft. I gave them to my FIL.

[David Weaver]

David,

Most old cast iron saw vise I have run across are quite inadequate when it comes to being sturdy enough to prevent vibration. The best one I've owned is a Disston 3D that I have overhauled so it will clamp tightly and evenly. I have even replaced the bench clamp with one that can be bolted to the bench. My main vise is a huge heavy duty Acme with 28" jaws.

Your method sounds like it is very solid and practical.

As for files..... most people on this side of the pond, when they can't find NOS files will buy Grobet. You can buy them from TFWW. I have so many NOS files, I've not had to by any yet, but when I do, they will be Grobet,s.

Marv

Grobets are good, but I like their swiss pattern machinists files better than their saw files. I like the NOS nicholsons the best of the saw files, followed by grobet swiss. Then the mexican nicholsons, bahco and simonds, I guess. I don't get too particular as long as the file cuts and doesn't have a ragged thick corner - they are all pretty good compared to any of the third-world files.

The woodworking retailers who sell the grobet swiss are too rich for my blood, though. I usually order files from mcmaster carr. They have been grobet swiss when I've gotten them, though they don't advertise brand, so there's no guarantee they'll stay grobet.

McMaster is a one-day ship to me, shipping is cheap, and the files are cheaper.

[Terry Beadle]

I wonder if the saw has been used in some hard wood with little or not set some time in the past. The heat generated in such a circumstance would be hot enough to cause a heat treatment.

I would be tempted to use a mapp flame to anneal the metal. Once softened, then file the teeth off or grind them with a eye out for over heating it.

Then refile the teeth to shape.

Then heat treat the saw teeth to R 52 ~ 53.

Then give it a good set and sharpening session.

Maybe I'm wrong....just wondering.

[george wilson]

Heating the saw hot enough to temper the teeth down would almost certainly result in warping the blade beyond repair.

Sawing hardwood would not begin to heat the saw enough to change the temper,and even if it could,it would only SOFTEN the blade,not harden it.

The tempering range to draw a normal tool steel,like 1095 to a spring is 750º F. That is when the blade turns blue. That is 50º BELOW a faint red hot in a dark room.

Your wood would be set on fire while sawing should you generate that heat!!

[Marv Werner]

What George said...

Marv

[Jonathan McCullough]

The tempering range to draw a normal tool steel,like 1095 to a spring is 750º F. That is when the blade turns blue. That is 50º BELOW a faint red hot in a dark room. Your wood would be set on fire while sawing should you generate that heat!!

That's why I suggested that it was tempered improperly at the factory; it wouldn't make sense for it to have been heat treated after leaving the factory. I can imagine a tempering oven being used too soon after installment or adjustment, and the temperature coming only to 350 F perhaps. Seems like they would have noticed something wrong when they were sharpening it though.

[george wilson]

Maybe it was a custom order from someone who had had trouble running into nails. No telling by now. I am pretty sure they would otherwise sent the blade back when they tried to file it. No way was this not noticed.

350º would have resulted in way too hard a blade,at about 60 RC. I've hardened many a punch at that hardness. I'd suggest about 600º+ for this hard a saw. I have no way to test its actual hardness from here,though. Could be a bit below 55 RC,but that might be pushing it,too. Just a few points over 52 would be plenty hard. In this particular area,I have had a lot of experience from making knives and punches,etc..

[David Weaver]

Just for confirmation to what I said previously ( i think in this thread ).

I ordered 5 more xxs 5 inch files for small saws from mcmaster - 3.95 each, and they are swiss origin grobets. I see a couple of other suppliers where the files are cheaper the smaller they get (there is a seller on amazon with grobets that size for less than mcmaster's with shipping included if you'll buy a dozen of them). I'm puzzled why the small files are less than half what they are from saw specialty places and hobbyist stores, esp. given that mcmaster isn't necessary competitive on price on a lot of things.

Anyway, very nice tidy files with good fine clean edges like the old nicholsons.