I just got a Disston No 7 dated to around 1875 for about $5 in good condition. I am having a hard time telling whether it's a rip or crosscut saw, as I don't have a crosscut saw to compare it and the teeth are dark with age. It's 10ppi and 20" long.
If it does happen to filed for a rip cut, can I simply file the saw as I would a crosscut and convert it to cross cut that way, or is there more to it than that?
Also, as long as the 6-sided (triangular looking) file is twice as thick on a face as the saw teeth are tall, can it be used? I have a file rated for a 6ppi saw and would use it on this 10ppi if that would be okay.
Thanks from a newbie sawyer
10 tpi blades are crosscut — rip teeth are more in the 8 or 6 tpi range (he says without going to his shop). Rip teeth are like little chisels, with the chisel-like teeth sharpened perpendicular to the blade and the direction of the wood grain. Crosscut teeth come to a point and are meant to Cut the grain, which runs opposite to the direction of the cutting/sawing. Someone MAY've sharpened rip-style on crosscut teeth, but I dunno why.
As to the file to use, files are usually (always?) longer on a side than the teeth they're used on. I can't say as I've Ever seen a file rated for a particular tpi, but I doubt I've seen everything even yet. *he sighs meaningfully and grins*
Thanks for the help bear_man. I gave it a go and the small saw was crosscut. Easier to see in good lighting and after taking a stroke with the file.
There's more than you're likely to need, or even want, to know on this subject here: http://wkfinetools.com/tRestore/saw/sawsRestore-index.asp (http://wkfinetools.com/tRestore/saw/sawsRestore-index.asp). Another good resource is http://www.vintagesaws.com/library/primer/sharp.html (http://www.vintagesaws.com/library/primer/sharp.html).
Rip teeth are more upright:
(http://www.vintagesaws.com/library/primer/ripprofile2.JPG)
than crosscut teeth:
(http://www.vintagesaws.com/library/primer/crossprofile2.JPG)
, in addition to the angles Bear_Man mentions.
And, while handsaw* rip teeth are generally coarser than crosscut teeth - the common rip pattern is 5-1/2 points per inch, while crosscut teeth are generally 10 ppi and up, with the occasional 8 ppi saw - there's no particular reason why some past mechanic might not have wanted a finer rip saw for some application.
*Handsaw being the 20-26" long saws with no stiffening back on them, the kind you find at yard sales everywhere.
Bill, thanks for weighing in. The second link in particular is quite helpful to newbies on restoring saw teeth, in my estimation. I was running only on memory when I replied..., and I forget why my memory ain't always what it oughtta be. (O:
Quote from: bear_man on July 20, 2014, 03:08:50 AMI was running only on memory when I replied..., and I forget why my memory ain't always what it oughtta be.
Yeah, I understand the memory is the second thing to go, after some danged thing that I can't remember what it is.