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Thread: Band saw blade welding
07-23-2005, 11:59 PM #1
I bought a HF band saw blade welder off E-bay. The first two blades I welded work fing. The next 10 or 12 have not worked at all. Does anyone have any tips for me. I am squareing the blade ends with a miter guage on a disk sander and have been getting good square joints, so that is not the problem.
Gary P. Hansen
07-24-2005, 12:13 AM #2
are you annealing them properly after welding?
there should be a "jog" or "braze" switch to
heat the weld and keep it from quenching in air.
what type of band stock are you welding....
most buttwelders specify carbon steel .
usually, "matrix " and other hi alloy blades
get electron/laser type welds in a factory,
and aren't specified for buttwelders.
i tigweld them when i have to in a pinch....
we need more info as to how they aren't welding right to give advice.....
07-24-2005, 12:48 AM #3
I have been trying to anneal the blades with the jog button. I may not being doing it right an the directions were written in Chinanees/English. Would you discribe how you doo it? I have been trying to weld carbon band saw coil stock I bought off a private seller on E-bay. I don not know the brand. I once heard some brands well better than others. Do you have any brands you care to sujest?
Gary P. Hansen
07-24-2005, 12:52 AM #4
Hold the button down til the weld starts glowing, release the button. As soon as the color fades, hold the button down until the weld is barely red (less than the first time), release. Hold down again for less time, release. Should be good to go.
07-24-2005, 01:17 AM #5
I try to do about 8 anneal cycles of reducing heat each time just as Barry said above.
Seems to work well so far.
07-24-2005, 01:18 AM #6
That is what I have been doing but I do not think I am getting it soft enought and sometimes it burns through. Maybe I should try a propain torch to anneal the weld? Do you have any favorate brands of coil stock?
Gary P. Hansen
07-24-2005, 02:39 AM #7
You don't have to get it to be bright orange. Just a deep cherry red is enough. To be able to see when it starts glowing, it might help to keep the lighting in your shop at normal indoor levels, not super bright.
The last few times that you jog the button, it shouldn't glow at all.
Test the annealing by flexing the blade to see if it will break. Then grind away the excess. You don't have to anneal it after grinding the excess.
Some blade welders have different places to clamp the blade. On those, you do the welding towards the back, where the jaws come close together, and then you pull the welded blade towards the front, where you do the annealing, and where there is more space between the jaws. The extra space allows a larger area to be annealed more uniformly.
Hope it works for you next time.
07-24-2005, 02:50 AM #8
I threw in the towel trying to get the blade welder on my Powermatic bandsaw to work (or should I say: gave up trying to learn the skills required to use it with any success).
I grind a very shallow angle on each blade end (opposite sides of the blade), then clamp the 2 ends into a little piece of aluminum that I milled with a slot to just fit the blade. Clamp the blade down with the ground/tapered ends overlapping, and silver solder it.
I have never had a blade break using this method. It's quick too.
07-24-2005, 03:00 AM #9
i use nicholson and simonds hardback .
i seldom buy bimetal....i tend to strip them
before they wear out....i've never had a "bad"
blade so far , so i can't say any one's better
or worse . i doubt a 10tpi raker set flexback
from doall/starret/morse/whatever is gonna'
be significantly superior to another...maybe
some elcheapo chinese brand might not be as good,
but i don't know.
i think the propane torch should work fine...just
don't overdo it ..or you'll anneal the teeth .
07-24-2005, 06:49 AM #10
precisionmetal, I do the same thing. I may have one in 20 or 30 fail at the joint but it is easy to fix. The success rate is much higher compared to when I was using a blade welder.
11-02-2005, 11:50 PM #11
PRECISIONMETAL and MIKE W,
Some help, please.  When you make the scarf joint, approx how long is your taper relative to the blade thickness?
 Do you think this method will work with bi-metal blades? [I must use bi-metal since I'm sawing very abrasive foams and composites --and cannot afford diamond-coated blades!]
THANK YOU VERY MUCH for your guidance.
11-03-2005, 12:09 AM #12
Tom, I grind the ends at about 22 degrees. I first tried 45 but the 22 gives much more overlap. I have yet to try bimetal but it should work. I believe MSC has a couple of blade welders and one was listed for bimetal blades. I don't know what the difference is.
I put a small amount of flux on the joint and use a very small oxy/act torch. It only takes a few seconds for the joint to get hot enough to melt the silver solder. I usually just file off the slight excess filler on the joint. It is easier then grinding down a blade done on an electric welder.
11-03-2005, 12:23 AM #13
0k,have yall had any problems with starrett blades? i buy their best blades but they only last maybee 30 mins and they break. i dont think im setting them too tight(but dont know for sure)ive been using this saw for quite some time but recently it has fallen to dis-use mainly because blades that last 30 mins at 27 bucks a pop get expensive fast.
11-03-2005, 12:29 AM #14
A trick I devised worked well... I had an old Powermatic saw, welder on it was not very good... But , I used the Tig torch, to flood the weld area with argon, while I used the blade welder. The welds looked like factory ones...
11-03-2005, 02:25 AM #15
Another vote for silver soldering here. I grind about a 30 degree angle on both ends, feather the ends for an overlap, and sometimes pre-heat the ends before cleaning. That last step seems to keep the oxides from forming as quickly as I reheat for the soldering operation. I clamp the ends in the jig, make sure the overlapped ends do not increase the thickness of the blade at the joint, then I pull back one end slightly to create a small gap- this does two things: it enables the solder to flow, and it helps prevent the blade ends from mis-aligning when the blade is hot and expanded. The feathered ends can ride up on each other, and because the blade is still very hot when the solder has solidified, you can end up with a join that's thicker than the blade. I don't like grinding away excess blade material to correct such a circumstance. Something else I do is leave one end of the blade somwwhat loosely clamped, so it can skid a bit in the jig as it's cooling. This reduces tension on the join as it's cooling, and makes for a stronger join.
I've been thinking of trying to make a ceramic clamp of some kind with which to pinch the junction as the solder is flowing in order to get a perfect thickness alignment. That might just squeeze out the excess solder as well, making cleanup really easy. Hopefully, the ceramic wouldn't draw the heat out too fast like pliars do.
11-03-2005, 02:41 AM #16
That is a good point about the 30 degree angle Darryl, I never thought about that. It would increase the contact area. I will have to do the math. [img]smile.gif[/img]
11-03-2005, 08:33 AM #17
At one time electric blade brazers were marketed; don't know whether they still are.
Oliver Machinery was one manufacturer and there were probably others:
11-03-2005, 08:43 AM #18
We had a bandsaw one place I worked with a band welder, it is the only one I have ever used a LOT, it was a good old line saw mfg. but I cannot remember, might have been a marvel, anyway I could not get it to anneal for beans, the propane torch worked GREAT for me, This was with Starrett band stock, I would anneal with the propane torch before grinding flush, and then re-anneal just a touch.
I have seen some that would not weld properly that if you looked inside the little lever that rests on a cam (said cam rotated by a control knob) to adjust either the heat or the mechanism can fall off the cam onto the shaft, then she is wide open all the time for a 3/4" blade. too much heat.
I will remember the silver solder bit tho,
If you wanted to get fancy I think you could mill the angles with a carbide cutter, you could make a jig to hold the blade while milling, maybe use the same jig to silver solder.
11-03-2005, 01:42 PM #19
Maybe I am a total tard, but I tried to silver solder a blade and it would not take. I mean, despite using the flux, it would not join the two blades sections together. It said silver solder on the solder. What might I be missing? I know this is supposed to work but for whatever reason, it is not.???
11-03-2005, 08:12 PM #20
I had welded1,000's of bandsaw blades...
I'll try to guide you on the prep..
Twist the blade stock ends back to back and on top of each other ..line the teeth up with the straight back of the blade to each other... (It's hard to do) Hold them tight together and grind the ends on the grinder as straight as you can...
When this is done...clamp them in you blade welder and make sure that the backs are parallel and no gap between the blades that are butted against each other. WELD the blade...
If it don't look right .. brake it and start over.if you have a nice even "flash" [img]smile.gif[/img]
Grind the flashing smooth...Annealed to a dull cherry red.. and TA-DA....A good welded blade [img]smile.gif[/img]
(They don't make blade welders just to end up brazing the blade together!!!)
This is how I was taught by my Father...
and I worked for Carpenter's Machinery in Philly
welding bandsaw blades
Any question contact me..