With the pervasiveness of table and miter saws, even in the hobbyist’s workshop, the trusty old handsaw doesn’t see as much use as when it was a staple. Still, most shops have one or two handsaws about, but since they’ve gone from the starting lineup to the minors, they’ll rarely ever be sharpened.
For the shop that still uses a handsaw regularly, it’ll need to be sharpened once in a while. When that time comes, do you just buy a new one, or take a few minutes to sharpen it yourself? With a file, patience, and practice you could probably do an okay job, but you’d more than likely be better off buying a proper saw sharpener like the Eclipse 38 from Spear & Jackson.
At first I couldn’t find much about how to use the saw sharpener — the manufacturer and retailers really don’t give that much information — then I found a forum in the UK where a guy posted the manual for the tool.
Looking at the picture, the top two bars guide the saddle and the lower one is the file. The saddle has three different slots to hold the blade in, depending on whether it needs to be cross- or straight-sharpened. Loosening the clamp screw on the handle allows you to rotate the file to the correct hook angle.
The Eclipse saw sharpener will run you $30 before shipping at Highland Woodworking.