What size saw files are really needed, and whats with "three square" files?

[Joshua Stevens]

Fairly new to saw sharpening, have the technique mostly down, but have finally killed the 3 saw files grandpa left me...now its time to buy more. I found a supplier of Bahco,(i hope) but my hang up is the size thing. Thanks to an Ebay orgy of (obsess much?) Disston no7s I now have plenty of saws from 4TPI down to 15. (def found out a man can justify "just one more" saw till he has no room for them !!! lol

So now for the great big ??? Jumping from blog to blog most show those great little charts where each saw TPI or PPI needs its own loving file partner, which is all nice and cutesy, but my god, a man with a decent (or ridiculous) number of different saws would need a case of each size made by that logic. So I thought before I mortgaged the house to buy stock in every size of Bahco or Grobet made, I would see if any frugal minded sawyers here have experience using say a 6" Slim to satisfy the needs of several thirsty saws of different TPI from their till? If so WHAT is the best or most used sizes to cover most bases?

and while I hopefully have anyones attention, whats the deal with "three square" files? Ive seen these on the Bay from time to time, and darned if they arent the spitting image of a normal tapered saw file? Im no machinist, so maybe was thinking they were used by someone in that trade? Can they be interchangeable with saw files?

[Jim Matthews]

Start here, with the Vintage Saws filing primer.

http://www.vintagesaws.com/library/primer/sharp.html

I follow the steps listed by Frank Brickhouse, when refurbing a saw.
These days, I stick to saws that aren't terribly rusty - it's a lot of trouble.

http://www.wkfinetools.com/trestore/...k/sawRest1.asp

Matt Cianci put together a solid presentation concerning some of the finer points.
http://www.wkfinetools.com/tRestore/...owIfile-04.asp

I would start with a 2x slim 6" and 5" for starters.
That covers most of the saws I need to be really sharp.

[Tom M King]

Different sizes of files are recommended for different TPI saws simply so that when one third of the file is dull, that it doesn't dull the adjacent parts, so that you have three complete useable parts of a file. Using a too small file will make you run out of useable sharp teeth quicker. Don't back up with a file and it will last longer. Backing up dulls the cutting edges twice as fast--at least. Save your files when they get dull. When you have a bunch of them saved up, you can send them off to be sharpened for a buck or so each.

Learn to use the whole length of a file. You might see videos of someone taking short strokes, but I usually buy full length files. Long light strokes can take off the same amount of material as short heavy strokes, and you get more of them out of any file. You can more easily get a tooth sharper with light strokes than with heavy strokes anyway.

[Joshua Stevens]

Tom,
First Ive heard of a resharpening service, do you have the company name? How many times can you resharpen a file? Do they just use an acid bath, or actually recut the teeth?

[Joe Bailey]

Tom,
First Ive heard of a resharpening service, do you have the company name? How many times can you resharpen a file? Do they just use an acid bath, or actually recut the teeth?

http://www.boggstool.com/

[george wilson]

As badly grooved as triangular file teeth get,from filing relatively hard saw teeth,I have doubts that they can be resharpened.

[Joshua Stevens]

thanks Joe! Ill have a talk with them to see how they do with saw files, makes sense what george said about the corners getting destroyed, do you or anyone have experience having sawfiles resharpened?

[Rick Whitehead]

thanks Joe! Ill have a talk with them to see how they do with saw files, makes sense what george said about the corners getting destroyed, do you or anyone have experience having saw files resharpened?

Yes, I have had saw files sharpened by Boggs, with mixed results.
Some of them were as George described: heavily grooved and VERY dull. Those didn't sharpen.
Some were just dull, and those were able to be re-sharpened. However, they didn't last long,becoming dull fairly quickly.I was using them in a Foley F-16 saw filer, so they were subject to more pressure than if I had been hand-filing.
To answer one of your original questions,the difference between a taper saw file and a three-square file is in the radius of the corners of the files. A saw file has a radius at the corner to give a rounded bottom to the gullet of the tooth.A three-square file comes to a sharp corner at the edge.
Rick W

[Mike Allen1010]

[QUOTE=Jim Matthews;2277256]Start here, with the Vintage Saws filing primer.

http://www.vintagesaws.com/library/primer/sharp.html

I would start with a 2x slim 6" and 5" for starters.
That covers most of the saws I need to be really sharp.[/QUOTE]


+1 To what Jim said. The guide in Vintage Saws for file size based on the number of points per inch is a good place to start. Given the overlap (two different size files can work for the same pitch saw), I tend to error on the side of longer and slimmer because longer is faster/last longer and slimmer gives you a little bit more room to maneuver in the gullet to get the final sharpening dead on.

In addition to the sizes Jim recommends, he might want to consider some 7" Slim/X slim for your 4-6 PPPI rip saws. Regarding the number of files you will need, you go through files a lot faster when re-profiling and tuning up a tooth line that is in bad shape (I usually use up 2 files per saw doing this), as compared to simply freshening up an already well formed tooth line, with well profiled teeth.

Best regards, Mike

[Tom M King]

Save Edge also sharpens files on the East Coast. It helps the numbers if you have some horse shoeing rasps in the mix too. I have some old Black Diamond files, that I found in my Grandfather's store (store had been shut and out of business since the great depression) that have been sharpened, I know, three times. I guess if you get used to long light strokes, that it must be easier on the file too. Also, it probably helps that I have never bothered to retooth a really badly out of whack saw-mostly just sharpening before it gets really dull, or helping some NOS Sandviks that I prefer.

[Jim Koepke]

Fairly new to saw sharpening, have the technique mostly down, but have finally killed the 3 saw files grandpa left me...

Someone else mentioned www.vintagesaws.com for information on saw filing and sizes. The reason for different size files is explained there. If the file face isn't atleast twice the tooth height it wears the other two sides prematurely. If the file is too much oversize the gullet suffers.

The trick may be in limiting your tooth counts.

jtk

[Bill Houghton]

Just to add some confusion, there are also non-tapered triangular files; Nicholson used the term "blunt" to describe a file that does not taper over its length. I've seen/held one or two of them. They're useful for general filing when you need a "V" shape.

[Joshua Stevens]

Rick,
Interesting, so Im guessing that the "three square" was more of a machinist type used to cut tight corner and such, and wouldnt work for handsaws at all?

Bill Houghton,
Yes, Ive also seen these "blunt" files from time to time, cant remember exactly the quote, but I do recall reading an article by nicholson back in the 1930s stating how some saw filers proffered the slim taper where others the non tapered file, and if I remember correctly the gist was that the best and most experienced filers proffered the non tapered, however the tapered was easier for novice or otherwise not so grand filers, but the demand was for that file as it catered to more people...

[Eric Brown]

A very old trick to keep a crack from spreading in bells, like the Liberty Bell, is to drill a hole at the end of the crack. That effectively spreads and redirects the stresses around the hole and prevents further cracking. The same thing happens with saw teeth. If the gullet comes to a sharp point instead of rounded, the tooth is more likely to break. Its also why fillets are added to welded pieces, to spread the stresses.

[Jim Koepke]

Here is a minimalist chart from the Tom Law sharpening .pdf:

Picture 1.png

It has been nagging at me because I knew I had it somewhere. Took me until now to find it.

jtk