Posts Tagged ‘disston’
Last week I picked up an excellent 26″ Disston D-8 crosscut saw with 8ppi. When looking for saws I shoot for a plate that is in decent shape, some rust is okay, but I’ll pass on blades that are kinked, have damaged teeth, or excessive pitting on the tooth line. A nice handle is a bonus, but those can be restored or remade entirely if necessary. I also look for hardware that is complete and hasn’t been chewed up by screwdrivers. Below is the saw I purchased through Craigslist for $10 and considering what these go for on eBay (when you don’t really know what you’re getting) this was a steal.
The Saw Plate: The saw comes apart easily, but use an appropriate screwdriver so the brass screws don’t get chewed up. My Lie-Nielsen #3 driver worked nicely. To clean up the plate, I started by scraping the surface with a razor blade scraper. This knocks down any surface rust and removes any old finish or residue that may have dried on the plate which will prevent the rust remover from reaching the steel.
After the scraping I soaked the plate for 12 hours in Evaporust. I made a simple trough by wrapping some scrapwood with a garbage bag. It’s just large enough and deep enough to hold the plate and minimizes the amount of Evaporust required to keep the plate submerged. After a 12 hours soak, I scrubbed the surface with a Scotch pad, then soaked for an additional 12 hours. Finally, I cleaned the plate with a brass-bristle brush, Scotch pad, and steel wool. Rinse the plate off with water, dry, and oil immediately. The plate is now ready for sharpening.
I won’t get into sharpening handsaws specifically. That’s an enormous topic with several books, DVDs, and websites dedicated to it. I would, however, recommend Ron Herman’s DVD on sharpening handsaws if you’re looking for more information. For a quick overview of file guides for saw sharpening, click here.
The Hardware: The brass saw nuts are easy to clean up, though you can leave them alone if you like the patina. I gently chuck each half of nut into my drill press using only light hand pressure. Too much pressure will damage the brass threads or crush the tapped housing. I run the press at a moderate speed, somewhere in the 700-1,200 rpm is a good place to start, then start working the face with abrasives. I start with 220 grit sandpaper and finish at 320. Each grit only gets 5-10 seconds of light pressure to do its job. The 220 removes and surface patina or any various types of shop grime. It also eliminates (or at least smooths out) dents and scratches. The 320 simply refines the scratch marks left by the 220. After sanding, polish up the face with a Scotch pad and finally 0000 steel wool. This leaves a relatively scratch-free, shiny surface. You can also use fine sandpaper (up to around 1,000 grit), but I don’t keep much of that on hand, so I chose the Scotch pad and steel wool as it was more readily available.
The Handle: Saw handles vary in condition. They can be so bad that they should be discarded and a new handle fitted, they can require some simple clean up and refinishing, or they can be left alone entirely. This saw had a handle in great condition, just some minor wear on a few edges. I’m tempted to make it look like new again, but there’s really no need and I have enough to keep me busy at the moment so for now I simply re-attached it as-is. For more information on making a handle from scratch, click here and here.
The Finished Product: I ended up putting about 1.5 hours into the saw as well as the $10 it cost to purchase. I’m quite pleased overall, now I just need a full sized rip saw and then I’ll probably have to make a new saw till to hold everything.
Sharpening hand saws is intimidating for most people, but there are some readily available options that simplify the process greatly. Here’s a quick overview:
Angles: Before sharpening, you need to determine the angles you want to file into the teeth of your saw. The rake angle is the angle between the face of a saw tooth and an imaginary line perpendicular to the baseline of the saw teeth seen when viewing a saw from the side. It is generally 12 to 15 degrees on a crosscut saw and 0 to 8 degrees on a rip saw. You also need to control the fleam angle, the angle that is filed across the face of the teeth, creating a knife edge that slices wood fibers when cutting. On crosscut saws fleam typically ranges from 15 to 25 degrees, rip saws typically have little to no fleam. (read Understanding Western Handsaws for more info)
Control: Once you know the angles you want to create, holding a file consistently and accurately for dozens of teeth in a row is tough. Fortunately, there are several options available to you that make saw sharpening fairly straightforward.
Option one is to make your own file guide. I picked this up from Ron Herman’s DVD and it works great. I made my guide out of some scrap cherry in about 15 minutes. The pictures will help explain the details, but the idea is to hold the file handle in your dominant hand and the file guide (with the tip of the file buried in it) in your off hand. Hold the file level and the edge of the file guide perpendicular to the saw plate. If you can do this, the guide will control the rake and fleam angles for you, it’s easier than it sounds. (You may notice my guide is using a 30 deg rake and fleam angle, this is fairly steep for both but it was deliberate for this saw. You typically want something closer to the angles listed above.)
So this guide works well in a pinch, but if you have several saws to sharpen you’ll quickly realize you need a new file guide for every angle combination you want… this may only mean making 2 or 3 guides, but for others it would mean making many more. So for all your file guiding needs there are a couple adjustable file guides you can purchase. A reasonably priced option was recently released from Veritas and functions along the same principles as the wooden block, but you’ll notice a variety of angle combinations and file sizes can be accommodated with this single device. A second option from Blackburn Tools gives you the same functionality, but in a much classier package and at a premium price.
I have not purchased a file guide from Veritas or Blackburn so far, but I have more sharpening on the horizon so I intend to shortly. Hopefully this gives you the confidence to pick up a saw (preferably a cheap one that you won’t mind practicing on) and get sharpening. It’s really very simple and Ron’s DVD, as well as various free videos from youtube and Lie-Nielsen, will provide you with all the information you need.