Tool repair: Hacksaws, Bench Grinders and ACE Hardware

As a known estate and garage sale habitué, it shouldn't surprise anyone that more than half of my tools are less than new & are sometimes purchased in need of love.

Today (out of a box of tools labelled "50 sents each") I got a reciprocating saw-blade holder. Really, just a handle that would let you use Sawzall blades as a small handsaw. This one was made by Craftsman, and except for the missing thumbscrew to secure the blade is in great shape. Of course I tried to track it down, but it either came as an included accessory of a reciprocating saw, or wasn't deemed worthy of maintaining parts for (the plate that grips the blade is trapped / non-removable, so the only replacement part *IS* the thumbscrew.) No matter, my local ACE hardware has a ton of bolts and thumbscrews, so an easy fix.

Took the handle to the store and using the bins of bolts determined that it was 1/4", 20 tpi (threads per inch.) Second step was to decide what sort of head I wanted - wing nut, thumbscrew, slotted, hex drive with round knurled side - lots of options. Having no idea what the original looked like (although I'm guessing low-profile knurled edge, coin-slot to tighten so as not to get in the way) I decided on a thumbscrew. I may have gone with something with a lower-profile head, but this handle can be used to grip the blade either way - straight up, or flipped 180 degrees, so if a thumbscrew would get in the way one way, I could simply remove and flip the blade and retighten and be back in business.
ACE "only" had 2 lengths in the thread size that I needed - too long, and even longer. I really only need 3/8" of threaded length and leaving it long would have gotten in the way even worse. So, in addition to the thumbscrew, I also bought a stainless steel nut of the right size, and a couple washers. Sure, I probably have those, but rather than finding them in the garage, it was easy to spend the extra 20 cents to save time. After I got home, I slipped the washers onto the thumbscrew and tightened down the nut - the threads under the washers and nut were about the length that I wanted. If I wanted to leave any longer length of threads, I would have bought 2 nuts and not bothered with the washers and simply tightened the nuts against each other. I then used a hacksaw (although using my reciprocating saw would have had a certain poetry to it) to cut off the extra threads. The next part could be accomplished with a hand file, but I wanted this tool to cost less than buying one new (time is money) so I used a bench grinder to smooth the end of the threads up to the stainless steel nut. Depending on how good your hacksaw job is, this can be pretty painless & accomplished quickly without the need for quenching.

I then removed the nut and washers, and did a trial fit. Note - one of the main reasons for putting the nut(s) on is so that you can keep the threads clean / relatively burr free. Simply removing the nut slowly can clean up / chase the threads a bit for you. That is why I spent the extra couple of cents on the stainless steel nut - as it was a bit harder than the thumbscrew, it was adjusting it, rather than the thumbscrew adjusting the nut. If there was room for 2 nuts, I wouldn't have bothered with stainless steel. Trial fit - a bit long. Replaced the nut without the washers and got a cube of ice from the kitchen. Too short to make an adjustment cut with a hacksaw, I would have to grind off about the thickness of a washer. Tightly trapping the "thumb" part of the screw between my thumb and cradled ice cube, I ground off what I needed, rounding a bit this time to allow easier insertion. I got the idea for using ice for grinding from Frank Ford's Frets.Com website. Thanks Frank! It works great! The whole site is interesting / useful, but his shop tips are wonderful.

To conclude - even if a part isn't available, there isn't any reason you can't find (and adjust) something into a suitable replacement. A minimum number of metalworking tools you should already have (hacksaw, bench grinder, files) will get you there most of the time. Ice is wonderful for grinding & will prevent you from removing temper and/or keep you from burning yourself. A well stocked local hardware store is worth its weight in... ...broken tools that would otherwise be binned or recycled. If it is a complex part, try the manufacturer first, generally through their website.

Circles and angles, part 1

I had a couple thoughts about circles and using circles to approximate angles and using circles to reduce angles.
The first (covered here) is that when you are using a bench grinder to rough grind a tool to a particular angle, the larger the wheel, the closer you will get to the actual angle - with a 12 inch wheel the difference is quite small. My illustration exaggerates the differences by showing 3" thick tools. Even a Hock iron for a Stanley handplane is only 3/32 inch thick. There are two schools of thought. First, if you like the look of a true angle, the larger 12" wheel size (which is nearly synonymous with the Tormek system) is better. Second, if you are re-honing the tool fairly frequently to keep a sharp edge, you will have to do less work if you started with a smaller diameter wheel & will only have to regrind when you finally bottom out / completely flatten the concavity created by a 6 inch or 8 inch wheel. At least that is what we folk without a Tormek grinder keep telling ourselves! Hehehe.
If you are grinding to shape the edge and then using oil or water stones or "scary sharp" sandpaper sharpening or any other flat sharpening system out there, simply sharpening the tool edge and the heel really does make a lot more sense. It is nice to have a hollow in the middle. The hollow keeps the tool from rocking (which can cause rounding) and causes you to hone less surface area. It does look weird to some people, however.