I have only broken 3 bandsaw blades in my lifetime so haven't had much opportunity to fix them, but I decided to make an exception in this case because the blade I had was still quite new and still very sharp to it was a good chance to see if I could be fixed the blade which snapped at the weld joint. These smaller blades for my little 12 inch Delta bandsaw which doesn't use a lot of tension on the blade so I think I have a pretty fair chance of getting this to work.
Watch it on Youtube: https://youtu.be/mqhsZl_cseA
I know many of the bandsaw blades appear to be spot welded together and I don't happen to own a spot welder by I have read of people who have solder the ends together with good results, so that is what I am going to try.
I have soldered my share of copper plumbing ... and quite a variety of electronic parts and I have a couple of torches and soldering irons but I still don't consider myself anything of an expert on soldering ... this will be more of an experiment than anything, and in the end, all I care is that the blade will work for me for a few more months, then it will be too dull to work properly and time to replace anyway. These blades are fairly inexpensive and last pretty well for their cost so anything I can get from it will be a bonus.
The first thing I needed to make was jig to hold the bandsaw blades with that would be straight fireproof, because I would be using one of my torches. I found a piece of angle iron that would work and cut a notch out of the middle as well as one on an end so that I could use the end notch to hold it firmly in my machinist vice. The angle iron worked fine, but because it is rounded at the 90-degree point I decided to add a couple of pieces of off-cut wood that had been rounded over and had been used on a former project. the round over fit nicely inside the angle iron and all I needed to do was epoxy the pieces of wood to the inside of the angle iron .. and presto, I had a nice flat straight line that I could align my broken bandsaw ends along so I can make sure that the pieces line up a straight line.
From what I learned, the best way of getting the 2 ends together is with a "lap" joint, which is where the 2 halves of the blade overlap, but instead of being square, I will need to grind the matching ends of the bandsaw blade in a bevel shape to help reduce the bulk that would happen when you overlap a could of bandsaw blades.
I tried using a flat file but that doesn't work, my grinding wheel has stones that are too rough so I finally settled on using my angle grinder with a finer blade to see if I could possibly grind that blade ends down a bit. As it turns out the angle grinder when attached to a makeshift jig that holds it in place .. works just fine as a grinding wheel.
After grinding the ends of the blade down to a beveled edge, I used some spring clamps and attached them to the alignment jig and made sure the grinds overlapped as they were supposed to do.
I read that flux you should be using for a job like this was a "power form" type of flux. I didn't have any of that couldn't find any easily so finally opted to use the flux paste that I use for everything else I ever solder together.
I fired up my propane torch smeared an abundance of flux on the aligned bandsaw blades and just ran the flame through the joint until I could get the solder to melt at which time it flowed nicely between the 2 parts of the blade. I let it cool ... it seemed fine, but the test is always - How Well Will it Hold ??
The test of the repaired blade was fine ... it worked like any other blade although there was a very slight noise as the joint passed through the wood I was cutting ... most people wouldn't have even noticed but I did. In the end, the blade cut just fine, I couldn't even see any difference between the repaired blade and wood I had cut before it broke.
The next test is to see how long it will last ... the upcoming days and weeks will tell me ...
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Copyright Colin Knecht