Saw sharpening plunge...

[John Dykes]

Thanks to those who gave me a comfort level on my e-bay saw purchase. I lucked out and for my c-note (yes, overpaid I'm sure), received a full size Disston #12 rip saw (6 ppi?) 1896-1917. Under the rust was some buffer (grinder?) marks, but it shouldn't affect performance. The blade has been thoroughly cleaned and waxed; it is in fine shape! There is a deep wear mark where one's index finger lays along the handle... I wonder about the man whose sweat is soaked into the wood.

My saw files arrived today. It is with some trepidation that I approach tonight's sharpening attempt. I have Tom Law's DVD and have watched it several times; I also have also read through the vintagesaws.com website. My novice understanding is enough to realize that rip will be easier than a crosscut... but...

I can't help but feel I'm being a bit dense, but here is my question. After jointing, you "shape" the rip teeth - ensure an appropriate rake (8ish deg is my goal) and evenly sized teeth. This is accomplished by running the file perfectly perpendicular to the blade yet parallel to the floor. This cuts both the front of one tooth, and the back of a second.

The very next step is "filing" or the actual sharpening. Where a new file side is used in the exact same manner.... Which, unfortunately, doesn't make sense to me. If it were creating the "fleam" in a crosscut saw, yes, I get it - but not in a rip saw.

While an admitted novice, I'm very much hoping to have that 1st wispy plane shaving feeling very soon.... but with a nice old Disston saw.

Regards,

- John Dykes
Denver, CO

[Mike K Wenzloff]

Hi John,

You might be simply over thinking it.

As regards using a fresh face on the file? Who cares unless you have used uo one face during repointing. I think Law assumes one will use up one face enough when reshaping that the file will simply cut better, cleaner, for the last pass or two.

The goal of repointing, or shaping, is only to bring the tips to the same height following jointing, making the tooth shapes fairly close to being the same as the others during the process. Whether the saw is to be a rip or cross cut makes no real difference, excepting the amount of rake and or a bit of fleam during the shaping of the cross cut.

When the teeth are fully shaped *or* when the teeth are within a pass or two of being fully shaped, the last bit is technically sharpening--the finishing off of the process.

fwiw, unless I have needed to do serious reshaping on a cross cut, I do use the intended cross cut fleam angle following jointing during the shaping (or repointing) process.

During the shaping process, you will most likely need to "crowd" the face of one tooth or the back of another in order to make the teeth even. The goal is to eliminate the flats evenly. For instance, the top of one tooth may have a very small flat from jointing, but the tooth directly in fornt may have a widish flat. You will need to "crowd" the file into the back of the toth with the wide flat, taking care not to eliminate the flat on the tooth that is barely there. However, on the face of the tooth with the wider flat, you will need to probably crowd its face unless the next tooth's flat from jointing is of equal size.

Clear as mud? Point is, one cannot just use an equal pressure downward if the flats are of unequal size. One needs to push or pull (crowd) the face or back of any given tooth if there are unequal flats. Too even of downward pressure when there are unequal width flats following jointing simply perpetuates the uneven tooth sizes that existed (assuming they are uneven).

Just take it slow. Be confident that the saw will in all likelihood cut much better than you received it. Don't sweat it if the rake angles are inconsistent. Same tooth height is more important.

Take care, Mike

[Bob Barkto]

It's really a matter of efficiency, not geometry.

When shaping most sharpeners approach all the teeth from the same side of the blade.
This leaves a rougher finish on half the teeth but improves speed and accuracy since all motions are the same and un-interrupted.

You'll also probably set the teeth after shaping which means a bit more touch-up to get the proper profile and remove any possible damage from the setting process.

And last but perhaps most importantly, the cutting force is smoother and more regular on the face of the tooth if the set points away from the direction of filing, so you will most likely flip the blade so the teeth are sharpened from alternate sides.
This gives the best finish to the face (cutting edge) but is a waste of time when shaping.




...
The very next step is "filing" or the actual sharpening. Where a new file side is used in the exact same manner.... Which, unfortunately, doesn't make sense to me. If it were creating the "fleam" in a crosscut saw, yes, I get it - but not in a rip saw.
...

[John Dykes]

Thanks to you both on pushing me forward on this evolution. I've never been accused of over-thinking anything (more on that in a moment).... Simple, mundane tasks like saw sharpening is perhaps a very simple task for the experienced hand. For untalented hacks such as me, it's a new world of challenges!

Mike - I appreciate your detailed explanation; and I do get it; and you are in fact very correct in your description. The teeth set to the right were all consistently very much higher than those to the left. So much so, I was worried that my 15-20 jointing passes (light, careful, newbie passes) might be leading me to getting the teeth recut.

After the jointing process, the teeth set to the right had considerable flats, while the teeth set to the left had very small flats (a few had no flats at all, but I was too timid to proceed with further jointing). I can see where the saw file must be pressured either forward or backward to ensure that the teeth flats are filed away evenly to ensure consistent tooth height. After seeing it, I think I get it. But...

Highland Hardware sells saw files - and recommended the 7" Slim Taper file works for 5-7 TPI. Applying the file to my 5.5 rip saw, it didn't feel quite right to me. After a bit more research, I'm going to track down a 7" Regular Taper file (which don't seem to be readily available).

So unless I can find a 7" Regular Taper locally at Woodcraft or Rockler, I may need to push out a few more days. Will give me some time to post pictures for some further feedback (criticism, guidance, hand-holding, etc).

Thanks again -

- jbd in Denver

[Steve Thomas]

John,
I think you are questioning the need to file the teeth again, are you not?

If you shape the teeth from alternate sides, and your rake angle is consistant. you should be left if a sharp saw. no? So no need to go back over the same teeth in the same direction with a new face of the file.

Is this your process.

Joint teeth - most have flat spots
Shape teeth - from alternate sides leaving you with evenly shaped, even height teeth
Stop... it should be good? if you did a good job.

If you shaped every thooth from the same side (faster, like a machine) you should re-file the teeth from alternating sides.

Then test cut.
If it tracks straight great, if not stone away some of the set from the offending side, until it tracks straight.

Good Luck

[Steve Thomas]

the above ignores setting... if you didn't joint much of your saw away then you will most likely have enough set.

[Mike K Wenzloff]

You can get 7" regulars at Lee Valley:
http://www.leevalley.com/wood/page.aspx?c=2&p=32952&cat=1,43072,43089&ap=1

But there are other places on the web as you have probably found.

fwiw, I use files that these lists consider to small--in other words one cannot fully use all three edges if you wear them out unequally.

Also, I don't know what you use to hold the flat file when jointing, but one can joint with the file tilted and it will make one side of the teeth *appear* more uneven than they are.

And as general info for everyone, sometimes teeth are in such poor shape that one needs to joint, file, joint, file (repeating as necessary) in order to not fully joint teeth completely away at any one jointing session as one is shaping the teeth.

However...variance in tooth size, rake and or fleam angles mean little. I am not advocating sloppy filing. And "perfectly" shaped teeth is a great goal, but the saw will work well with variance in those things.

Oh, and do note that if you switch to a regular saw file at this point in time, it will not fit down into the bottom of the gullet (in all likelihood). So it will ride up onto the face and back for X number of strokes.

Take care, Mike

[John Dykes]

Thanks again for the replies.

All I've done thus far is joint the teeth with a mill file. I made a simple hardwood jig that holds the file flat across the teeth. I'm mostly confident that I'm not titling the file. I'm quite sure the teeth were very uneven.

Steve, your process of joint, shape, set if needed, sharpen a bit if needed is my thought process at this point. But again, I'm only at the joint to even height stage. I may even consider pursuing Mike's method of joint, shape, joint, shape. I'll know after my first shaping attempt. I did attempt the "heel-most" tooth for a 2-3 very light strokes with the slim taper, but decided to wait for the regular taper file.

Lee Valley has had 7" regulars "unavailable" for some time. But I found some at sharpeningsupplies.com and I'm having them send 2nd day air :eek:(should be here Thurs). The delay will give me time to adjust my homebrew wooden saw vise... the saw handle prevents getting the heel-most teeth gripped. May have to rethink it...

Again thanks and warm regards. It's very comforting for the untalented to have such experienced hands and the one of the world's premier saw makers guiding them. The time and effort is noted and appreciated more than can be stated.

- jbd in Denver

[John Dykes]

My 7" regular tapers arrived last night, so I took to sharpening my #12 Disston rip saw... And to be honest, I don't know how I did - though I'm a bit worried, that even with the utmost research and care, I did a poor job.

My expectation was uniform teeth and gullets... And Lord, it looks to me that gullet depth and tooth angle aren't terribly consistent. After shaping and setting, I tried ripping a bit of Borg poplar. Admittedly, I didn't "sharpen" the saw after shaping, nor have I ever ripped a board (I know, I'm trying...), but the results were poor - it certainly wasn't a "joy to use."

I'm aware the faults are mine, and not the saw or the wood, but I'm not sure how to move forward. Should I send go ahead and take a true sharpening pass (as stupid of a question as this sounds)? Should I rejoint and shape (perhaps with a smaller file?) attempting to get more uniform teeth and gullet depth\shapes? Buy a cheaper Borg saw to practice on? Send it off for sharpening to see what a good, sharpened saw looks like?

I'd reviewed a few articles, vintagesaws.com, and was pausing Tom Law through the process, but I don't know how to gage success (or failure). While my fragile man ego doesn't like it, I think I need a bit more help.

Would pictures help? If so, of what?

- jbd in Denver

[Tim Leo]

LIGHTLY joint the saw and try shaping the teeth again. Sometimes it takes more than one pass to get it right.