Cutting and Mounting the Blade

One might think the big trick to this whole thing is cutting the old saw up, but it really isn't.  There is no big trick to any of this project - but one does need the right tools, though really not that many.  A hacksaw would probably work, but its much, much easier if you use a couple simple power tools.  Here's what I used:

I already owned a couple skil saws, of course, so the only added cost is the blade for the saw (about $5.00).  I also purchased the pneumatic cut-off tool from Harbor Freight on sale for about $10.00, so the final cost of both tools wasn't much to worry about.   The skilsaw worked better for the longer cuts because my air compressor isn't enough to keep up with the cut-off tool for very long - but because of its size the cut-off tool was much handier for the shorter cuts, such as the slots in the blades for the stair saws.    I used a little layout dye to make seeing the mark I wanted to cut easier:

The cut needs to start straight, as its hard to straighten it out as you go along (and impossible to do well) .  Where there was just a little bit to do, I brought the blade over to the grinder to remove some of the material.

After cutting, I thought it a good idea to go in with a large file and smooth the edges so I wouldn't cut myself, and so the blades would fit where they were supposed to go better.  It also was needed to straighten the edges of the new blades.

Here are the finished blades, before I add teeth (note the slots cut into the stair saw blades that allows them to be adjustable for height):

Because I was going to handle them quite a bit, I waited to add teeth to the blades until the very last, so I will here, too (why risk cutting myself on freshly sharpened teeth?  I do it enough already!).  I wanted them to be at their final shape so I could mount them in their respective handle before going too far, though.  On one, the largest, I kept the teeth from the previous saw so I wouldn't have to cut the teeth for it again.  If they are sharp, one should consider using a pair of leather gloves while handling it in later parts if attempting a similar project.

When you have the blade to its final shape, fit it into the saw cut you made earlier.  It was very tight for me, so I fashioned one of the left over scraps of saw blade into a makeshift scraper:

Just the right width, it worked great for getting the width of the saw cut just right for the new saw blade.  Use a burnisher to draw an edge like a regular scraper if needed.

Mounting the Blade in the Handle

First thing needed for mounting the saw in the handle is a pair of screws.  There are 2 sources for these screws - used ones recovered from old saws (of which there should be some left from the saw being cut up) and new ones.  The old ones are often nicer, and brass - but I'd rather keep mine for replacing missing ones in old saws.  New ones are getting scarce, but are still available.  I found these through acehardware.com (item #20066 replace saw handle screws) for something like $7.50 for 10 sets.  One might check with Lie-Nielsen or Adria tools to see what they have available.  Here's a shot (taken at a later stage) of the saw screws:

Sorry for the focus of the picture, I suck at close-ups.  

Anyway - the holes that are drilled for the screws must be precise - or the blade will feel loose in the saw.  There are three things to look at here, and to account for when drilling the holes.  First, The screw is what determines the size of the first hole to be drilled, this one was 7/32".  Mount the blade into the saw as it will be when its finished, and using a drill press, drill through the entire assembly.  

Second - the nut (on the right in the above photo) has a larger diameter (this one used a 5/16" bit).  The nut should go on the "back" of the saw... so I flip the saw so the "back" is up in the drill press.  It doesn't reach the blade, so I set the stop on the drill press so I didn't cut into the blade, and enlarged the holes that were just drilled to accept the nuts.

Third - at the top of the screw, there is a squared off portion (the screw is on the left in the picture above, and in the inset just for a better view of this).  This is to prevent the screw from turning when tightening.  Don't try to force this portion into the hole, use a small chisel (I used a 1/8" chisel) to square up the hole on the "front" of the saw to accept this.  Failure to do so may result in splitting the wood.  I know this from experience - I had to re-make the smaller stair saw.  Impatience has its virtues, though - mostly in acquiring more practice.  I am very practiced, if that is the case.

When finished with drilling the holes, I removed the blades and file the rough edge left by the drill in the saw blades so they could be slid into place more easily.  For the stair saws, I then cut the slots from the top, so the saw could be adjustable.  The cut-off tool mentioned above was invaluable for this step.  Then a final test fit, with the saw screws in place and tightened, and I was ready for the next step.