Good job, and very clear presentation! I think you're the only one that understands about the gap, I have read that there's an optimum joint thickness for silver solder, this is published by the manufacturers. I also think a file is best for cleaning up the joint, since it can make a smooth surface, and only cut the silver. I bend the blade over something very slightly convex to do this filing. I really enjoyed when the sound suddenly came on when you did the test!
So Concise no waffle this is a premium entry to youtube..Thank you so much may others copy you presentation, slick, tidy and straight to the point (no pun)
Actually a common brazing rod will work and is a lot cheaper than silver solder. You need a fairly soft alloy and a Mapp torch. Propane isn't really hot enough. And if you do a lot of band saw work, it is a whole lot cheaper to buy your blade stock in 25-50 foot rolls and make up your own custom blades.
How much more life do you get out of these repaired blades? During my meat cutting days, we would use the blades till they were ridiculously dull or they snapped. They usually snapped after they became dull. Do you somehow resharpen your repaired blades?
I use a lot of band saw blades for wood. This process would be a silly waste of time. You have a blade here made from a single grade of steel (not bi-metal and not welded carbide teeth). If it is brittle enough for the teeth to hold a good edge for a little while then it is brittle enough to get general fatigue from the constant bending and unbending. If you repair one break, its just going to break again somewhere else almost immediately. In the long run you can save time and money by using the most expensive blades available in the first place, and then when they are done, throw them away.
Your technical comment based on material engineering and fatigue is absolutely right. I bleave, this repaire prosess will help us when blade failed by accident not by the end of its durability.
I think regular carbon steel bands have harder teeth, and the band is spring temper. Think of how a chisel or knife or other tool is tempered, the body of the tool is not as hard as the cutting part usually. I think this is true for saw blades. I have made some blades (from rolls of bulk material) by silver soldering, and some lasted a long time, and some didn't! I think there is much room for improvement here, also I was using "easy-flo" solder and not "hard" solder, it should be possible to make this kind of joint that is entirely as strong as steel!
What size is your blade? I have done this in the past with 19x0.9mm blades aka 3/4''x0.035'' metal cutting blades and they break after 4-5 cuts in the brazed joint. I think the blade tension on larger blades is too much for a brazed joint
Was that a bi metal band saw blade? It could've been greater if you've showed the process thru video. Not by slideshow. I have Haltbar band saw blades. I broke one last month but it was my fault. I attempted to repair them I just made it worse.
AT 53 SECONDS YOU SHOW A "FLAT ROTARY FILE" MY QUESTION IS, WHERE DID YOU GET A FLAT ROTARY FILE? I NEED ONE BECAUSE I DON'T HAVE ONE. THANKS FOR ANY INFORMAITON YOU CAN SHARE.
We can supply 3inch (80mm) wide 0.8mm 0.9mm or 1.1mm thick untoothed and how ever many meters you want for a great price bohlore or udderhome 000 brand steel