Brent Beach posted a lot of information on saw-filing on his site, and 
designed a jig which you can make to help you file saws. His method has 
worked for me.

http://www3.telus.net/BrentBeach/sawjig/index.html

FWIW
Don

On 2020-06-12 6:52 p.m., Frank Filippone wrote:
> I never thought to use this saw as a rip saw. Maybe I did not explain the
> saw is about 18 inches long. Teeth (not yet measured, but I would guess
> around 14 or so) are really dull. It will be used as a crosscut saw in a
> miter box.
> I guess, if the saw has both xcut and rip teeth, I get to choose. Since I
> will use it for xcut, it will need xcut teeth.
> Never filed xcut. New skill to learn.  (Fleam?).
> Thanks gang. I knew this was the place to get a response.
> Thanks for the reading and tutorial references. I will review them all.
> Frank
>
> On Fri, Jun 12, 2020 at 5:28 PM Christian Gagneraud 
> wrote:
>
>> On Sat, 13 Jun 2020 at 11:09, Frank Filippone 
>> wrote:
>>> I have a 50-60's Diston backsaw I must sharpen to use.  Is it filed rip
>>> or crosscut?
>>>
>>> On this particular saw, it looks like....both..... depending on where I
>>> look......
>>>
>>> It is pretty dull, and needs a full cleaning as well.... Lots of work to
>>> get a really nice saw back in shape.....
>>>
>>> But how do I file it?
>> Hi Frank,
>>
>> Use a magnifier glass if you cannot see with your bare eyes.
>> Rip cut teeth should show a line, cross-cut should shaw a triangular knife.
>>
>> Paul Seller has a few interesting video about saw sharpening (and saw
>> teeth): https://www.youtube.com/channel/UCc3EpWncNq5QL0QhwUNQb7w
>>
>> Blackburn tools have very good online materials, check out:
>> http://www.blackburntools.com/articles/saw-tooth-geometry/index.html
>>
>> http://www.blackburntools.com/articles/practical-cross-cut-saw-
angles/index.html">http://www.blackburntools.com/articles/practical-cross-cut-
saw-angles/index.html
>>
>> On one of his videos Paul Seller claims that there is not much
>> difference b/w cross-cut and rip cut for fine saw (i guess above 14
>> TPI).
>>
>> Filling for rip cuts is easier, so unless you intend to use your saw
>> with a mitre box and your saw has fine teeth, I would say that a rip
>> cut filling is your best bet.
>>
>> Backsaws need a perfectly flat tooth line, i use a level (fro
>> flatness), and i check for flatness with a feeler gauge. I usually try
>> to reach b/w +- 0.2mm to +- 0.1 mm.
>>
>> Chris
>>
>>> --
>>> Frank Filippone BMWRed735i@g...
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