How to Make Custom Length Bandsaw Blades Without Welding

[stevec]

Greg, no offence but does that silver soldering look a bit lumpy? The stuff I use flows more liquidy (is that a word?) and leaves a lot less to grind off.

[f350ca]

Your going to have to come over and show me Steve. Some of what you see there is the flux, but there may be a little excess, the solder Im using is maybe a little large, I think you can get thinner wire which might be better

[chucketn]

I am having trouble soldering the blades. I have 45% silver solder, and past flux bought at the welding supply that is supposed to be for silver solder. The flux is a clear paste. The solder does not flow enough to penetrate the joint.
I will post pictures of my jig and a attempted joint later today.
BTW, I'm using a Mapp gas torch.

Chuck

[f350ca]

Im more familiar with the white flux, its water soluble. Soldered the blade in the photo with propane, doesn't take much heat to warm up the light blade.

[chucketn]

Well, I got out the digital camera and headed to the shop to take pictures of the jig and the flux I was using. Typical, the camera lit up and when I took the picture, it went black... Batteries died! So, batteries charging, pics tomorrow.
Meanwhile, the past flux I was using is Radnor Stay-Clean. Says on the bottle it contains Zinc Cloride, and not recommended for Aluminum or electronics soldering. Is this the right stuff?
I taught High Reliability Soldering for electronics in the USAF for 10 years, so I have some knowledge of soldering, just not much on silver soldering. I remember my Dad soldering with an Accetylene/Air Torch, which I now have, but that was 40-50 years ago.

Chuck

[TomG]

Chuck,

Zinc chloride flux is for lead solder and won't work at all with silver solder. Also, the 45% solder you have is probably not going to be strong enough for bandsaw blades, you need some that is at least 50% silver.

You should be able to get the right stuff at a welding supply or at the following link:

http://www.gesswein.com/

The solder should be 50-55% and the paste flux say that it is specifically for silver brazing.

Tom

[chucketn]

Well, Tom, I guess the guys at the welding supply didn't know what they were talking about, because I asked them. I think it was Air Gas. I have another place in Jonesborough to check.

Chuck

[chucketn]

As promised, pics of my jig. Big Brown is supposed to be delivering the proper flux today from MSC. We'll see if that works any better.

Chuck

[chucketn]

Eurika! Flux from MSC did the job. 2 tries with first blade, 1 try with second! I tested the joint on the first one by flexing in my hands and then sucessfully coiling the blade!
Thanks Tom for the jig, and thanks to all that perservered through my learning! What makes it special is I used solder I found in my Dad's torch kit!

Chuck

[TomG]

(03-05-2014, 01:42 PM)chucketn Wrote: Eurika! Flux from MSC did the job. 2 tries with first blade, 1 try with second! I tested the joint on the first one by flexing in my hands and then sucessfully coiling the blade!
Thanks Tom for the jig, and thanks to all that perservered through my learning! What makes it special is I used solder I found in my Dad's torch kit!

Chuck

I love happy endings!

Keep in mind that if you do get some blades that break, it's likely due to the solder. The 45% you used is quite a bit weaker than 50-55%. Just something to keep in mind.

Nice job on the fixture.

Tom