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Pros, Cons, and Practical Reality of using bandsaw blade welder?

S_W_Bausch

Diamond
Joined
Jan 15, 2010
Location
Indianapolis, Indiana, USA
Bandsaw blade welder? What are Pros, Cons, and Practical Reality?

Seems the old tech bandsaw blade welders are not suitable for the bimetal blades, so who values the ability to use bulk blade, instead of bi-metal?

:stirthepot: I just don't know, I've got a buddy who doesn't see the value in bi-metal blades, and it got me thinking.
 
It usually is not worth welding your only blade. As you said the typical blade welders found on saws are only good for carbon blades. A bimetal blade last much longer and cuts faster so the savings is in cut speed and time that would be lost to change blades. Here the typical weld charge is around $3. per weld.

The main advantage of welding blades is if you want to cut the center out of block. You first drill a hole in the block that is larger the blade. Thread the blade strip that is cut to the right length through the hole and then weld it. Install the blade on the machine and cut the center of the block. When done break the blade and remove. This was comon for tool and die makers in days gone by. Modern wire EDM has taken this over.
 
Modern wire EDM has taken this over.
Opinion: For non-precision jobs wire EDM is hopelessly slow and expensive and threading a bandsaw blade through a hole will remain a valuable technique in shops that 1) need to make interior cutouts, 2) don't see a machining center as the only way to cut, and 3) value their time.

BTW, brazing (silver solder) is a perfectly viable alternative to welding for bandsaw blades. I don't have a blade welder. In the rare occasions when I need to make an interior cut, I split and braze a blade. Can't say for certain if I've brazed bimetal blades, but I've definitely brazed hardback blades.
 
I guess it comes down to how much you value your time, and whether you work for money or not.
For me, its not worth it. Bi-metal, all the way, as I cut at least 50% stainless.
If I am careful, I can milk a bi-metal blade for a month, of actual working weeks.

Carbon blades, on the other hand, often croak within a week.

If you can afford the time to find bulk blades on ebay, and a cheap used blade welder on ebay, and you dont mind fussing, then it may be worth it. When I have employees working (which, these days, is not as constant as it was) the last thing I want to pay them to do is fuss around. I want em to slap on a new blade, and keep cranking.
 
I've had good luck butt welding carbon and bimetal blades with TIG. Grind excess, peen, and file smooth. I've used both regular mild steel and stainless filler.
 
I have a DoAll 1216 vertical saw with the blade welder.
I have welded Bimetal blades with no problem.
Just anneal a few times as recommended and it works.
Have not had one break yet.
I have heard to only weld carbon steel blades,
but I don't know why people say you can't
weld bimetal blades. Somebody welds them.
Maybe the pros have a secret like welding them
in an inert atmosphere? I doubt it.
SDC10351.jpg


--Doozer
 
I weld 1/4" bimetal blades routinely without trouble, on a 50's DoAll welder. If you are having trouble, it's probably in the annealing.


Doozer - love the flames.
 
I also routinely weld bimetal blades on a DoAll vertical saw. I anneal after welding and again after grinding the weld smooth. Dunno if that helps but it makes me feel better and I haven't broken a weld in a few years.
 
Having a good welder makes all the difference. I have had several, I have a doall on my saw and it works ok it gets the job done. I have had one of the ones enco sells it worked and thats about all it did. Then I got a stryko and my whole world changed. That thing makes perfect welds that dont break and you dont have to even try it does it for you. I weld bimetal all the time but I do comb Ebay for rolls of cheap blade. As long as I am using the saw the blades last months but the minute I let some else run it they seem to mess it up.
 
I weld 1/4" bimetal blades routinely without trouble, on a 50's DoAll welder. If you are having trouble, it's probably in the annealing.


Doozer - love the flames.

Yup! At this point, welding a blade takes about the same amount of time as threading the saw and changing the guides. Having a couple thousand feet of coil stock on hand ensures I won't run out.

Ya, the flames are neat!
 
SDC10352.jpg


SDC10355.jpg


SDC10354.jpg


SDC10350.jpg


Eye candy for you.
I had a GF that did the pinstripes for me.
Too bad things were not meant to be.
I miss her.

--Doozer
 
SDC10576.jpg


PS- Someone send me their spare Job Selector for my machine. Thanks!

Notice the dual Moffatt Lamps?

--Doozer
 
Can someone explain the reason there might be a difference in welding a Carbon blade VS a Bi Metal blade with any given size welder?
Looks like from the posts here, there is no problem, yet the 'myth' seems to persist.
I've always had a hard time imagining the difference between the blades welding requirements with any type welder.
IOW, if the welder has the amps to melt a given size blade, why would carbon VS bimetal make any difference?

Doozer.......nice saw!
Always wanted a 'real' verticle similar to that.
 
Dan, this sorta explains the difference between a butt welder like you find on a vertical saw and a flash butt welder like a stryco. About Flash-Butt Welding | T. L. Fahringer Company

I'd say the biggest difference is in the quality of the weld, and not necessarily whether the blade is carbon or bimetal. I've got a normal butt welder on a vertical saw and also have a Stryco MF-2 flash butt welder. There's no comparison in the quality of welds between the two.

I got the Stryco for near nothing and only use it for repairing blades. Never have had much luck finding any stock I could use on ebay, and buying bulk stock at retail is a loser. I keep a few used blades around and if I strip a section of teeth out of an otherwise good blade, I'll cut a foot or two out of the blade and replace it with a section from one of the used ones. The stryco has a blade shear on it, and a perfect fit between the blade ends isn't near as critical as on a butt welder, so the whole thing takes maybe 10 minutes. Well worth the time to save a $50 blade. The stryco makes equally good welds on both bimetal and carbon blades.
 
Cliff,

Thanks for the link...

I thought someplace I even saw the welder specs themselves listed as different capacities for Carbon, and Bimetal??

I've got an old stand alone DoAll, model DBW 4C, made by Contenital Machines.
Picked it up at a small auction, also, for almost nothing. Haven't used it yet, the jaws need some re-surfacing and adjustments.
DoAll has a number of the welders listed on their website, along with the manuals, but this one
is not listed. It looks like it would weld 1" blades from the clamping jaws.
The price of a roll of stock (especially 1 ") has so far been to scary for me, and the factory welded
blades, one or 2 at a time seem to be the best bet.
I would like to get a roll of 1/4, 3/8 and 1/2 for the vert saw tho...

dk
 
I remembered a brazing jig I saw years ago, and here is what I found just today. The brazing anneals the immediate joint area. You will loose a few teeth, and if you can put up with the interrupted cut from that try this:

BANDSAW BLADE WELD JIG

paul
 
[/QUOTE]BTW, brazing (silver solder) is a perfectly viable alternative to welding for bandsaw blades. I don't have a blade welder. In the rare occasions when I need to make an interior cut, I split and braze a blade. Can't say for certain if I've brazed bimetal blades, but I've definitely brazed hardback blades.[/QUOTE]

What is your process for brazing blades? I have tried several times and built a jig for holding them, but have never had any luck making it work.

Thanks, Chris
 
What is your process for brazing blades?
I don't have a picture handy, but 20+ years ago I bought a kit with a simple jig, some flux and some brazing ribbon marketed primarily to woodworkers. This product is a bit more elaborate than what I got. Basically, the jig provides two reference planes to align the blade ends and two clamps to hold them in position. The reference planes have a gap so the joint is in free air, ready to be torched.

My first step is to scarf the ends of the blade. Hold the loose blade ends in the desired relative position (teeth on the same side of the blade, etc). Then "fold" the not-yet-brazed joint so that the loose blade ends rest on top of one another. Shift the end on top so it sticks out further than the end on the bottom. Hold them in this position and take them to the bench grinder. Grind the ends on a plane tilted roughly 15 degrees to make long, shallow faces on both ends at the same time. This increases the joint surface area tremendously. By grinding both ends at the same angle, when you "unfold" the joint for brazing the ground joint faces will match automatically.

Second step is to place the blade ends in the jig. If you haven't already done so, clean the ends of the blade so there's no oil, resin, or other junk near the joint-to-be. I place the ground faces in contact, not trying to allow anything for joint thickness. If the blade ends aren't flat, bend them so they are in light spring contact. The jig provides locators for the faces and backs of the blade ends, so you really only have to pay attention to axial positioning. After clamping the blade ends, the blade should look pretty much continuous even before brazing. If there's a noticeable kink, angular mismatch, or other discontinuity, fix it now.

After the blade is secure, flux the joint and place a bit of brazing alloy in the joint. I much prefer the flat ribbon for this operation over the usual small diameter rounds. Then heat the joint with a propane or MAPP torch until the brazing alloy melts. Let the joint cool, then grind off any flash or excess thickness in the joint.

This works pretty much 100% of the time on blades of 3/4x0.025" or smaller. I don't see any reason it wouldn't work on larger (say, 1x0.035" or 1.25x0.045") blades, but don't have 1st hand experience with that.
 








 
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