Band Saw Blade Brazing

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mrb37211
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Band Saw Blade Brazing

Post by mrb37211 »

Anyone familiar with electric brazing of band saw blades? Apparently it was quite the thing at one time. Here are a couple of pictures...maybe.

Image

The one above (Electro) apparently is fairly modern, as the address on the sticker uses a zip code.

Image

This one, an Oliver, is circa 1920s.

Both pictures came from eBay listings. I copied the Electro myself. someone else copied the Oliver and posted it to the Old Woodworking Machines site.

Charles
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Flybynight
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Band saw

Post by Flybynight »

:? Interesting.
just yesterday a guy called and wanted to know if I Braze band saw blades. I said I have seen welded blades but not brazed.
He said a guy Silver solders them for him, but he would like to braze them.
Seems he grindes each blade one half thickness and alines the teeth and solders them up.
I guess I will try and braze one and let U know how it comes out.
Jim
heavy_groover
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Post by heavy_groover »

I've read numerous posts in RCM that silver soldering (with a small torch) is a completely suitable method of joining blade ends. Silver soldering is essentially the same process as brazing, and the terms are probably used interchangeably.

The basic operation is to grind a beveled overlapping (scarf?) joint in the blade ends, then hold them in a fixture to braze the joint. To grind the joint, the ends are held together (one on top of the other, with one end rotated), grinding the bevel to both ends at the same time. This will produce the overlap thru the blade thickness dimension.

Those are interesting looking machines.
The Electro appears as though it might have carbon jaws/contacts, but they might not be. The wire leads don't appear to be large enough to carry very high current, so it would be interesting to discover how the Electro unit works.

The Oliver is a little more mysterious.

When welding is the process, the machine provides low voltage, high current and a bit of lateral motion to force the hot ends together for a short distance. This occurs quickly, causing some of the blade material to expand at the joint. This upset is then typically touched up with a small grinding wheel to maintain a thickness consistent with the blade thickness.

The welding may be followed by a brief application of current to anneal the joint before the grinding.

HG
Mike_W
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Post by Mike_W »

I silver solder mine. I use a small oxy/act torch. This is what I use to keep the blade straight.
Attachments
Bandsaw blade jig.JPG
Bandsaw blade jig.JPG (27.65 KiB) Viewed 9324 times
ME75

bandsaw blade

Post by ME75 »

Do you bevel the ends or grind to allow overlap as someone else described here, or do you just butt them together, to silver solder? I have been wondering about this, or also possibly TIG welding the band together. Don't know why a good TIG weld wouldn't work as well as the electric welding technique that is commonly used for the purpose. The standard bandsaw welder uses what is basically just a spot welding process, which is nothing special as far as I can figure. TIG should be equal to that in quality I would think. I have a couple of big metal cutting bandsaws I would like to be able to make blades for. I've got a bunch of bi-metal band. I'm a little nervous about silver soldering or brazing for this because of the tension involved as well as the flexure. One of these takes a one inch blade. The other is inch and a quarter. Anyone got any experience along these lines? Oh, and the saws have hydraulic tensioning as well. I thought about building a bandsaw welder, but for the size blade I'm looking at it takes a good sized machine. May do that eventually anyway, when time permits Got a big stud welder that would more than supply the current. But if TIG will work, that's probably my answer, at least for now. Great Forum! I just found it. Thanks Bob
Mike_W
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Post by Mike_W »

I have heard of guys that tig weld the blades. I grind mine at about a 22 degree angle to get some overlap. I don't get many failures. I like old blades for tig practise.
Attachments
Band saw blade.JPG
Band saw blade.JPG (33.9 KiB) Viewed 1038 times
doogdoog

Post by doogdoog »

Aloha Mike,
Neat looking weld!

Mahalo,
doogdoog
rays

Post by rays »

I have one of the electro units . I use it for silver soldering blades.
mrb37211
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Post by mrb37211 »

Rays,

Did your Electo come with any instructions, parts manual, or other paper? If so I would like to obtain copies, as I am now the proud owner of the one in the picture. Don't have an Oliver as per the other picture, but downloaded two sets of instructions for different models from the Old Woodworking Machines site.

My email is cbrumbelow @ comcast . net Remove surplus spaces.

Thanks, Charles
Bernie T
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Re: Band Saw Blade Brazing

Post by Bernie T »

As per 2005 thread I too have ( The Electro bandsaw Brazer) and instructions in print would be a help,I did find the video on the web but that is all.you can send any you have to Bern-Mary@comcast.net Thanks
Lew Hartswick
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Location: Albuquerque NM

Re: Band Saw Blade Brazing

Post by Lew Hartswick »

Here are a couple of "devices" I built just before a new teacher caused me to depart and then the Covid crap came along when the teacher problem was finally solved , and I never got a chance to try them out in practice . :-)
Image

Image

Image

Image


...lew...
old chipmaker
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Re: Band Saw Blade Brazing

Post by old chipmaker »

Many many moons ago all my blades were silver soldered and they held up fine. Now I use a DC powered electric blade welder made by Car Mover. Its fantastic, and quick, and does regular carbon steel as well as bi metal. Only downside is it needs a fully charged 12 volt car battery.
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