Help soldering broken bandsaw blade

I have silver brazed ( often called silver soldering ) numerous things using small propane torches. Propane is hot enough. It is no problem to silver braze bandsaw blades using silver braze. I have done it. Silver brazing larger objects takes some thought. Insulating fire bricks ( IFB ) are useful. You can take some IFB's and build a little corner that keeps the heat from being conducted away. Silver braze flows at dull red heat.

=20 Dan

One tip on grinding the scarf joint. Take the bandsaw blade and twist it so that the sides that need to be ground are both on the same side and next to eachother. Then grind both ends simultaneously. Helps to get the same angle on both ends.

Dan

Please keep us posted.

There is a lot of tribal knowledge advising against use of 'soft solder' for band saw blade welding. I am interested to know your experiences with longevity of the joint.

Thanks!

--Winston

Typical British attitude. Encourage others to do what you don't have the stomach for.

Forget their skull. Too thick for a rivet. Maybe a 'blind' rivet? ;-)

That's your mistake. You don't "think" you need the 'real' stuff.

You do.

Lead free solder has no tensile strength to speak of. It doesn't come close to resembling silver solder, even if it *is* silver bearing solder.

Get the 'real' stuff and enjoy success, although you must have a greater lap area if you don't want to experience joint failure.

Harold

If he sends me an address..Ill send him a bit of actuall Silver solder

Gunner

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch

Nope..wont work. Lawyers dont have a heart.

Now if you launch a rivit at about 3000 FPS and put it into the brain pan..that works!

Gunner

One could not be a successful Leftwinger without realizing that, in contrast to the popular conception supported by newspapers and mothers of Leftwingers, a goodly number of Leftwingers are not only narrow-minded and dull, but also just stupid. Gunner Asch

Looks like I'll be using some of the advice on this thread in the near future to repair a blade and shorten a new one. One blade broke today so I went to put a brand new Lenox Diemaster 2 blade on the 4x6 and tightened it up and the adjuster went solid, on checking the blade is too long and the upper wheel hits the casting, bummer!. I've used dozens of the Lenox blades and not had this problem before, no blade welder so silver soldering will be the answer.

(...)

I'm interested in your results.

Please share.

Thanks!

-- Winston

I have purchased boxes of a half dozen alloys of silver solder. Some are vary hard and require a hotter flame, others flexible and a lower flame.

Mart> >

Amen to that!

Silver soldering is sometimes referred to as hard soldering.

It's become more confusing because old style rosin core electronics soldering is going leadless and slowly replacing the lead in lead/tin solder with a percentage of silver. When I used to hard solder large stainless steel vacuum components to copper and brass fittings, we called it hard soldering and it was the "hard" high silver content solder that came in long thin rods like brazing rods and required oxy/ecetylene to bring up to useful temps. Of course I'm talking heavy metal mass, not thin saw blades. Bernzomatic torches may be enough for thin saw blades. The key is the flux. That Sta-Silv flux is the best. Very forgiving of wide range of temps, even severe overheating.

nb

(...)

The black 'high temperature' stuff rather than the white stuff, yes?

--Winston

The black is primarily for stainless steel, but we used both interchangably. If I were buying only one for general use, I'd go with the black.

The stuff is water soluble, so it will eventually dry out and become crusted over in the container, even completely dry out. Even new jars sometimes have a crystaline crust on the top. Not to worry. Just add water and remix. Its normal consistancy is a paste, about right to put on with a simple acid brush or small spatula knife. Don't be afraid to lay it on thick. Better too much than too little.

When the joint is hot enough (dull red), the flux will bubble and boil and then become like warm honey, flowing everywhere and filling and whetting the joint. Add the solder to the edge of the joint and let it flow into the joint. If it doesn't flow into the joint, it isn't hot enough or you used too little flux. Try and use only as much solder as needed. Too much and it will flow out the bottom and drip and you will end up having to grind down the blade so it will fit in the guides.

Water will clean up the post solder flux crust. A good stainless steel brush, the fine ones that look like a tooth brush or a small wheel is good to dress it all up.

nb

Excellent. Thanks!

--Winston