Bandsaw Blade Repair - How to Solder Bandsaw Blades 

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You're welcome! Thanks for watching.

You're welcome! Thanks for watching.

Thank You, Mark!

Madness! I have thought of TIG welding, and then dressing and annealing? But I have the silver solder and flux, an ounce of solder might be good for a lifetime. I've found some silver-brazed blades to be as durable as anything, and some come apart, so it still needs work.

Thank You!

Thanks for watching!

Bill Carroll the flux for silver solder, is the same?

Percy Flores yes, as far as I'm aware it is. I have never seen different flux other than a paste and a liquid form.

Agreed, i think silver solder is a better choice if you have it kicking around the shop. Thanks for watching, Bill.

@@knecht105 is brass stick good for soldering bandsaw blade?

great job. that is how its done

yuk yuk... me too ;(

I had my doubts, too :) Thanks for watching and subbing!

Richard Grier the flux for silver solder, is the same as used in this video?

Each time that I have purchased silver solder, it came with a tube of flux. IMO, it (probably) is exactly the same!

It was really just a test to see if it would work. I prefer to replace that blade also, if possible, but this method should get you out of a bind.

Hope it helps! Thanks for watching!

I've enjoyed watching you and used several of your 'tips' Colin, great and thanks again. Keep'um coming.

You're Welcome!

Thank You!

Agreed, replacing the blade is preferred, but this repair should get you out of a bind if you don't have spare blade kicking around. Thanks for watching.

I bought a jig years ago and have soldered several over the years. You have to use silver solder though

Silver solder is used to hold down 5ton hydrallic jacks.

I think the metal is too thin to braze, but yes, solder is very soft and brazing is much stronger if it were possible.

I used to braze to some very thin metal James, but after more thought, & although it would work for Colins task, the heat needs to me more sustained, so it would take some of the spring out of the blade, however it would still cut wood, and would save it from the scrap bin. I hope Colin does a follow up on this as it is a very interesting idea.

I agree that a braze or spot weld should be better, but I was really just testing this repair option out, to see if it would work. Maybe in the future, I'll borrow some oxy acetylene and do a brazing test also.

​@@kevsbuild2807 When brazing with 50% silver brazing alloy, the temp is a couple hundred degrees lower than using brass filler. This is right around the critical temp for steel,* so this indeed heat treats the steel. But the band cools so fast in air that it re-hardens. I'm not privvy to the inner circle of band manufacturing, but I bet the blades are air cooled to begin with, with the band running through a furnace with a small opening on either end, and when it comes out the other side there is perhaps either passive air cooling or perhaps compressed air is shot over the teeth to speed the quench. But that's a guess. Any rate, you can't tell the difference in hardness after a proper silver brazing. After the passive air cooilng, the joint has just about exactly the same resistance to bend/flex and springiness as before. But any time you harden steel, you should temper it after. In this case the proper temper is about when the steel turns blue. If you overdo the temper, the area of the joint will indeed be softer and will tend to yield/bend and take a set at that spot. Many people don't temper, at all, after brazing. And such a blade will for sure work 100% fine with no temper for at least a "good while." But it might break, prematurely at a seemingly completely random interval of use. Same thing will happen to a homemade wound music wire spring. It will work, it will compress/stretch, it will spring back. It will act like a spring. But even kept within the demonstrated operating specs, it can fail via an out-of-the-blue breakage where it snaps clean in two, if you don't temper it after forming it. The tempered spring (or blade) will not suffer this sort of failure. The hardening (or the bend-forming of hardened steel) step leaves internal stress risers that can lead to tiny internal cracks, which over many bend cycles will tend to grow. Tempering takes this edge off so that these internal microcracks don't form to begin with. *One advantage of silver brazing over brass is this lower melting temp. When you heat treat, you want to bring the steel just barely to the critical temperature, where you can just barely detect a dull red glow in indoor lighting. If you used brass filler, you would have to get the metal bright red, maybe even orange. This would produce the same problem you have when resistance or TIG welding a band. It introduces large grain defects when the blade passively air-quenches. You would have to re-harden the metal to just cherry, after. (Some people call this step annealing, but I think it's more sensible to call it re-hardening in this context).

Yes, I think silver is a better choice if you have some kicking around. Brazing it with bronze should also work well, but I've never tested it. Thanks for watching!

Thank You!

Another guy who did this heated the blade red hot. Doesn't take much heat to melt solder me thinks.

Aluminum is a better conductor of heat than iron. Seems it would take longer to heat the blade before the solder would run. Or perhaps you are thinking that the aluminum would draw away the heat so the blade doesn't lose its temper. Looks like it is a horse apiece. Can go either way. I'm not an expert. Perhaps you have more expertise in this area than I.

Imho I guess that you have never made a RU-vid video on woodworking! Do you know how much time is involved for making such a video? It takes hours and hours for making good content and good quality. So 2 videos per week is nearly a maximum. I prefer quality above quantity.

Hans de Groot : I am aware. I was joking in a manner that indicated that I love these videos (or so I thought...)

OK. I like these videos too very much. They are straight to the point, very comprehensive and informative.

On most band saws the blade is mostly enclosed. If the blade breaks it might make a loud noise, but it doesn't go anywhere, partly because it instantly loses tension, so there's no drive and it just stops. The saw motor is still running but the blade isn't moving, you see?

Thank You!

Regular. Silver Solder a good choice if you have it though. Thanks for watching.

JusBidniss Ain't gonna happen. The blade just stops, after it snaps.

Tom Ahoks - spot on. The sound is a bit scary...but never has it been dangerous. I have broken about a dozen over 20 yrs or so.

That's soft solder! Mostly TIN. Hard solder might be half or one quarter silver, flows at a red heat.

Thanks, I've fixed the article link. I used regular solder and typical use a torch, so I'm not sure with the min and max temps would be. I would suggest using silver solder if you have access to it.

You're welcome. I have only very few experience with soldering (only some wires) so I have been searching on the internet for more information. I know there is "soft soldering" till 450 C and "hard soldering" (brazing?) with temperatures till 1200 C or even higher. Torches (burners) for soft soldering can cost as little as 25 USD but torches for hard soldering can cost ten times more, 250 USD. Could you please mention the brand and type of burner you used for this particular project?

No, Definitely not strong enough. there wouldn't be enough surface area for epoxy to work plus the heat generated when cutting would break down the epoxy.

@@canonmanmart Ah. OK, thanks.

Silver solder (and steel) might be five to ten times stronger than epoxy!

Károly Herczeg is for weld electronic components.

The point is the flux would be borax

Thanks for the tip and thanks for watching!

Silver solder might be ten times stronger than electrical solder! Roughly as strong as mild steel, maybe more under ideal conditions.

Nelson Baietti no it’s not that serious. It always makes me jump and gets the blood pumping but because it’s incased in the saw it doesn’t do any real damage.

As Morgan mentioned, the noise and action of it snapping is the scariest part in my experience. Thanks for watching.

It tends to just tangle up a bit on the bottom wheel i did work with a guy that claims he was injured by a snapping blade but i doubt it there isn't enough space for the blade to escape through the guard

NO! It usually makes a loud noise, but the blade is shrouded in the machine, and in most cases when a blade snaps it loses tension instantly and stops. The machine has a lot of momentum, but the blades might not. Especially thin light blades as used in home woodworking as we see here. I have some blades that only weigh an ounce or two, when they hit the casing of the saw they stop right away.