Bandsaw blade bevel

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SteveM
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Bandsaw blade bevel

Post by SteveM » Mon May 06, 2019 9:26 pm

I have several hundred feet of bandsaw blade my dad left me and I need to start making blades.

I know about grinding the ends square, making opposite bevels, clamping it all in a jig, fluxing and brazing (silver soldering with real silver solder, not the Home Depot stuff).

As I stood at the grinder to start, I thought about scarfed joints in belts and how you want the joint aimed a certain direction.

Would that be true in the case of a silver brazed bandsaw blade?

If so, which way should I go? Should the point on the inner side be pointed into or away from the direction of travel?

I think this would only affect how it goes around the wheel, because when it's making the cut, no matter which side is beveled in which direction, one side or the other is going to point into the cut.

Steve

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Re: Bandsaw blade bevel

Post by Harold_V » Tue May 07, 2019 1:17 am

Because the blade sees the cut from both sides, it doesn't matter which side leads. You have that correct. Lap joints on belts for belt sanders are an example of which side leads being critical. You don't want the leading edge of the joint to see the material first, as it has the potential to hook, which immediately destroys the belt. Different game with saw blades.

One thing that is important is that the overall thickness of the joint not be thicker than the blade stock. DoAll provides a gap gauge on their welders, which allow you to determine if the blade will run without binding. You may not need the gauge, but make sure you measure the joint to ensure it won't bind in use. A gauge makes it real easy, though, and that's something you can make using a slitting saw of the proper width.

H
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spro
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Re: Bandsaw blade bevel

Post by spro » Tue May 07, 2019 1:42 pm

I agree a matching bevel allows more braze contact/lap joint.

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Bill Shields
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Re: Bandsaw blade bevel

Post by Bill Shields » Tue May 07, 2019 8:40 pm

i must be truly wonky..I have never beveled or silver soldered a band saw...or even thought of doing it that way.

I always just grind the ends square, shove them in the 'welder', get them hot and push them together and grind off the excess..

sort of like welding RR track....although the 'gauge' as Harold describes is a bit beyond what you can do with a slitting saw...
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John Hasler
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Re: Bandsaw blade bevel

Post by John Hasler » Tue May 07, 2019 8:46 pm

That's fine if you got a 'welder'. Many of us don't.

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Bill Shields
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Re: Bandsaw blade bevel

Post by Bill Shields » Tue May 07, 2019 9:03 pm

I didn't have one for 40 years..

before I got my welder, I used to 'borrow time' at a local shop who had one.

$30 in the evening, off shift, and I could come in with 20+ prepped blades all ready to go, weld them up in an hour and be on my way. Worry about the grinding etc: when I got home and be out of their shop.

STILL cheaper than purchasing pre-made blades.

I recently got one off a junk band saw from the scrap yard auction didn't even bother taking the saw...just removed the welder and went home....it's a real POS but welds. The grinder and 'saw chopper' were junk (which is why I got it for virtually nothing)...

I can sit down (on the floor) (it's mounted on a 2 x 12 now... and weld up a dozen or so blades in an hour, then put it back in the corner for another year.
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spro
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Re: Bandsaw blade bevel

Post by spro » Tue May 07, 2019 9:13 pm

I was going by what the OP asked and remembered the jigs to do it that way. I use a blade welder for years. The Grob is 220v . This one doesn't have a grinder but has a slicer. It doesn't use much amps at 220v single phase. The older DoALL has a grinder and really nice shoes and stuff but draws 30 amps at 115v. These units are heavy with all that copper winding. If I had many hundreds feet of blade, I would buy one.

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SteveM
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Re: Bandsaw blade bevel

Post by SteveM » Tue May 07, 2019 9:13 pm

I managed to get a respectable bevel on opposing sides, clamped it up to the jig my dad made, fluxed, heated and soldered.

I'd like to brag that I even got the teeth to line up (they did) but that was just dumb luck.

Other than having a bit too much solder and having to grind more, it appears to have come out OK.

Not a lot of noise when the joint comes around, and it's SO much nicer trying to cut wood with a sharp coarse blade than with the dull 24 tooth blade that was on the bandsaw when I got it.

Steve

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Re: Bandsaw blade bevel

Post by spro » Tue May 07, 2019 11:49 pm

That sounds great Steve. With a welder, I can't really know how the teeth align after fusing. The back of the blade is perfect straight and that is important. The joint must be annealed to be flexible. That is another setting on the welder and sometimes I grind off before annealing. Then the final side grind and height of the teeth. There shouldn't be a noticeable interruption at the joint but sometimes it works. It is hard to explain but the teeth dig a little deeper in a millisecond, presenting new territory for the hundreds to explore.

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Re: Bandsaw blade bevel

Post by Harold_V » Wed May 08, 2019 1:58 am

Bill Shields wrote:
Tue May 07, 2019 8:40 pm
although the 'gauge' as Harold describes is a bit beyond what you can do with a slitting saw...
Hmmm. Not sure why you think so, but I'm all ears.

A screw slotting blade will create the desired gauge without issue.

H
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Re: Bandsaw blade bevel

Post by liveaboard » Wed May 08, 2019 4:02 am

35 years ago, a friend of mine proudly showed me his blade welder.
He died a few weeks ago; I'm sure that machine is in his shop somewhere [with a hundred other treasures], and no one will even know what it is.

I have a big old wood bandsaw; I used to get blades made cheap, but can't seem to find that now.
They want like $50 for a made to size rip blade.
I wish I could get my hands on that welder...

spro
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Re: Bandsaw blade bevel

Post by spro » Wed May 08, 2019 6:19 pm

Terrible bad about your friend passing. Its like you don't want to bug him while he is ill. He's going to get better. Then he dies and maybe left a will, maybe not. I can't take it. I mean, I've lost or they are no longer here, many and more to come. I just have to think they are still around but I cannot contact them.
One way or another get a blade welder. Coils of blade stock are still relatively efficient. I don't know about the HF ones but the older ones, well I was lucky. You certainly don't want to see any coil damage or evidence it had burned. Often there is a lot of refurbish at the shoes, clamps and cleaning all contacts. All the stuff you can do. It is still a welder with particular way of pressuring the aligned blade ends at the same rate as the amperage.

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