Replies

1. 
   mike4244 | Apr 08, 2009 02:40am | #1

   I have several D8 saws.The rip saw is 5 1/2 tpi ,the crosscuts are 8tpi and 10 tpi.

   I also have a 5 1/2 pt crosscut D8.This was originally an 8 pt saw that was found in a basement of a home I bought. I had a professional saw service file this saw into a crosscut saw keeping the same teeth configuration. I used this saw much more than the others. Very fast and less tiring for framing lumber cutting. This was my "cordless saw".

   I imagine your D8 was originally a ripsaw and someone tried to recut teeth to an 8 pt crosscut.The 7 1/2 pt at the toe of the saw was not factory filed,at least I do not recall ever seeing a saw like that.I am not sure that 7 1/2 pt was standard for Disston.

   mike

   
   

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   Edited 4/7/2009 7:41 pm ET by mike4244

1. 
   mwenz | Apr 08, 2009 05:09am | #2

   Most rips leaving a factory had higher ppi at the toes that progressed pretty evenly to a few ppi less over the remainder of the saw.

   Most rips seen prior to say 1900 or a little later that do not have a change towards the toe were repunched to make saw filing by machine easier (possible).

   Take care, Mike

1. 
   woodhors | Apr 08, 2009 09:57pm | #3

   Thanks for your reply. Your description fits my saw correctly. When I put the end of my rule on the first tooth I count 7 1/2 which goes down progressively until finally when I start about 4 inches from the toe I get 5 1/2 TPI which stays that way for the remainder of the edge. Should I take this as evidence that the saw dates from the early 1900"s? My big problem remains - Should I file the edge to a straight line? My reading seems to indicate this. That is I believe one of the purposes of "jointing" the edge. On the other hand 1/4 inch is a lot to file away and I think I could sharpen the teeth within the curved envelope. Thanks again! - Woodhors

1. 
   dkellernc | Apr 08, 2009 11:28pm | #4

   Your saw is likely to be "breasted";  that is, the tooth line is a convex curve.  This is intentional, and is meant to yield a faster cutting saw.  Saws made in the golden age (pre 1920's) made for roughly cutting wet softwood would have extreme breasting - convex on the order of a couple of inches.

   Unless the saw is very, very dull, you might try ripping a softwood board and see how it performs.  You will likely have to do nothing other than lightly touching the cutting edge with a triangular file to make the saw quite useable.

2. 
   mwenz | Apr 09, 2009 04:09pm | #5

   Hi Wood,

   The purpose of jointing is to level the tips of the teeth to their neighbors. A breasted saw--one with a curved edge like yours--should remain thatta way. In jointing a breasted saw, just allow the file to follow the arc. Use light pressure on the flat file (especially if it is a newish file) with a slightly raking light. Once most all the teeth have the reflective flats from jointing, it's ready to file.

   Go slow on filing if this is your first saw. Look at the metal that is removed in the first tooth pair after a light stroke or two to see if you have copied the present angles. The shiny portion is where the file is removing metal. Once you go over the saw from heel to toe, if you need to file more, the easiest way to be able to see the future effect of filing (between the teeth will be shiney) is to saw into a board. The saw dust will lightly coat the teeth. This will allow you to see the effect of where you are filing again.

   Take care, Mike