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+-- Thread: Repairing bandsaw blades (/showthread.php?tid=7332309)
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Repairing bandsaw blades - blackhat - 08-07-2017
What's the preferred alloy and flux when silver brazing bandsaw blades?
RE: Repairing bandsaw blades - mike4244 - 08-07-2017
I use silver solder tape and the flux is white Superior # I don't recall off hand. I bought both from SRI( Stan Rubenstein industries) .Any specific questions they will answer you on the website.
mike
RE: Repairing bandsaw blades - Steve N - 08-07-2017
You can find a lot about bandsaw blade repair online, but nobody makes a call on flux. My best friend is a machinist, and he has an old Do-All with an annealer, so I do most fixes there. If you want to solder use any metal work flux, white flux is very common, it's just a vehicle, and all of them will work. I use 50/50 solder, I've seen from 40/60 to 45/55.
Posting this video, he doesn't even say anything except flux, and solder, but he shows a number of things to try to mimmick on dressing the ends of the blade, and supporting the ends is critical, he shows a nice way to clamp, very important to clamp well, or your shifty ends will bring about shifty results.
If you know a machinist, check to see if there is a Do-All, the cats a..
RE: Repairing bandsaw blades - blackhat - 08-09-2017
Guess I'll find out how 45% silver works
RE: Repairing bandsaw blades - daddo - 08-10-2017
I see by the video, I did it wrong. Mine failed after two cuts.
I should have used my 45% instead of 15%. I butted my edges with no taper.
White flux worked fine though- I got good flow and adhesion.
RE: Repairing bandsaw blades - EricU - 08-10-2017
45% should work great. Flux goes with the filler. I use safetysilv or staysilv from Harris for 45-56% silver. The one thing you have to worry about with a Mapp torch is that an underpowered torch, paradoxically, makes it easier to overheat. The flux tells you if the steel is the right temperature, when it goes clear, it's time. Control the heat by flicking the flame off of the blade and then back on. Don't leave it still, you will overheat and cook your flux. I should make a video
RE: Repairing bandsaw blades - Arlin Eastman - 08-10-2017
I used to do it on our Do-All metal bandsaw while in the military and it annealed it also. There must be someone around that has one or even a business who should not charge more then a dollar or two.
RE: Repairing bandsaw blades - Steve N - 08-10-2017
A DoAll with an annealer is like free money. It works on all occasions
RE: Repairing bandsaw blades - mike4244 - 08-14-2017
(08-10-2017, 07:22 AM)daddo Wrote: I see by the video, I did it wrong. Mine failed after two cuts.
I should have used my 45% instead of 15%. I butted my edges with no taper.
White flux worked fine though- I got good flow and adhesion.
Butt joint probably will never work. Most people use a scarf joint. I use a half lap instead. This is difficult without a milling machine. You can also use a file, the metal is soft enough . I would suggest using the side of a grinding wheel. Back the blade up with a piece of wood for stability. I make the half lap or even a scarf joint 1/2 width of the blade. Example, 1/2" wide blade is scarfed 1/4" on each end. 1" blade ,1/2" each end etc.
I use an aluminum angle iron with a notch cut out in the center of the bottom leg for the torch. The angle keeps the blade aligned and is held down with 2 small C clamps. Silver solder won't stick to aluminum. Heat from under the joint. The metal being thin will take seconds with propane torch to get the solder to flow. When cool you can grind or file any excess solder.
I use silver solder tape and white Superior flux. SRI ( Stan Rubenstein Industries ) sells the tape and flux. Not cheap , I do this often enough that the cost means nothing to me. If this is only for one or two blades I believe you can buy a small amount from a supplier, Maybe Rockwell?
mike
RE: Repairing bandsaw blades - jasfrank - 08-14-2017
I usually use 45% SS but have done some with an oxy-acetylene torch and bronze rods using white flux. Never had any come apart either method.