Re: New saw
William R. Duffield on the Cohansey
>Frank has the right idea.
You might get a better guess at what the previous owner used it for by closely examining the teeth. If they are filed rip, then it might have been used for carcase dovetails and tenon cheeks. If they are filed crosscut, then it would more probably have been used for sawing tenon shoulders, miters, cutting molding, stiles and rails to length, etc. It is pretty coarsely toothed for a saw that short, at about 7 PPI, and near as I can tell from the photo, the rake angle would indicate it was probably filed cross cut. It is definitely too coarsely toothed for the finest detail work required for small drawers, boxes, etc., made from thin stock.
However, you have to decide what your needs are, and therefore how you want to sharpen it to meet those needs. You could leave it the way it is, or you could refile it rip, if you wanted to use if for sawing tenon cheeks, or you could retooth it with a few more TPI for cutting carcase dovetails, or even more teeth, again filed rip, if you wanted to use it to cut dovetails for drawers and smaller pieces. If you wanted to use it to cut muntins and finely detailed furniture molding, you might want to retooth it with a lot more teeth, but leave it filed crosscut. For large moldings, heavy duty tenons, e.g. for entry doors, etc., (finish carpentry taskes) a longer backsaw would be more appropriate, but this one will also work, with its currently coarsely set teeth.