Bandsaw Blade

This topic has 20 replies, 11 voices, and was last updated 22 February 2013 at 18:58 by KWIL.

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24 January 2013 at 17:39 #109890
Kevin Bennett
Participant
@kevinbennett25223
This has probably been asked before but how successful is Brazing a M42 Bi-Metal Bandsaw Blade as i have 2 in good cutting condition and i do not want to throw them out.

Suggestions please

ty Kevin
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24 January 2013 at 17:39 #22433
Kevin Bennett
Participant
@kevinbennett25223
25 January 2013 at 08:17 #109941
CuP Alloys
Participant
@cupalloys
Hi Kevin,

As Kevin suggests make a scarf joint. Make the tapered length 3 – 4 X the thickness of the blade. Allow a small gap say 0.1 -0.15mm

Flux with high temperature flux eg HT5.

Cut a small length of low melting point silver rod – say 1.0mm or hammer a thicker rod down. Place it on top of the joint and heat from below. Capillary action will draw the alloy into the joint. Allow to cool naturally.

regards

keith
25 January 2013 at 20:20 #110042
Kevin Bennett
Participant
@kevinbennett25223
Thanks for the advice i think i will experiment on 1 of the blades and turn the second one in to Bi-Metal hacksaw blades cut to length & drill holes at each end . i have just ordered 2 replacements from Tuff Saws.

Thanks for your help

Kevin
29 January 2013 at 22:03 #110449
Joe M
Participant
@joem
Kevin.

I had the exact same problem with a smaller blade. I logged on to you tube, typed in Bandsaw blade repair and found loads of positive links which were some help. Good luck with it. You don't need too much heat though.

Joe
30 January 2013 at 19:47 #110529
Sub Mandrel
Participant
@submandrel
Try using a cook's blowtorch. Worked for me, though the results didn't last a particularly long time.

More successful than MMA welding… more like plasma cutting!

Neil
30 January 2013 at 21:04 #110531
thomas oliver 2
Participant
@thomasoliver2
I have silver soldered many bandsaw blades with easiflo No 2 and they have never broken at the loint. Scarf as suggested. The main problem however is keeping the blade in alignment. My jig is an 8in length of 3/4in x 3/4in steel angle iron. A notch is cut out a the middle to allow the flame of the torch to heat from underneath. Hold the jig in a vice and clamp up the two halves of the blade with two small G cramps. Apply the flux as a thick cream and place one tiny piece of silver solder on the flux. Heat gently at first or the flux will bubble up and disturb the solder. Increase heat until solder flashes into the joint. Too much solder wll build up and is not easy to remove. TomOl.
21 February 2013 at 12:09 #112725
Speedy Builder5
Participant
@speedybuilder5
For those that that like making tools, try this web site.

http://www.modelismevapeur68.com/soudure_lame_scie_a_ruban.html

Its in French, but loads of info for making a bandsaw blade welder. If you want the plans, click on telecharger (Ie download the PDF files for free) I had to go onto the web to find a WINZIP version 17 to un-zip the files.
21 February 2013 at 14:47 #112730
KWIL
Participant
@kwil
In the video, no attempt is made to anneal the joint, other (professional) butt welders reheat the joint post-weld to ensure the welded area is not too hard.
21 February 2013 at 15:37 #112732
Kevin Bennett
Participant
@kevinbennett25223
Has anyone attempted to make a homemade simple band saw blade but welder it would be nice to make one , most people on this site have the skills mechanical skills it is the electrical things i will have a problem with

Any openers in this question

Ty Kevin
21 February 2013 at 15:55 #112733
Les Jones 1
Participant
@lesjones1
Hi Speedy Builder5,
I found that that downloading the free version of winzip 17 took me to a site that wanted you to register for something before allowing the download. 7-Zip works and is straighforward to download frome here.

Hi Kevin,
The schematic looks very simple. I suspect the transformer used will be an old transformer from a microwave oven with the original secondry removed and replaced by a few turns of very thick wire. I am going to see if I can find a website that can translate the french text on the schematic to english.

Les.
21 February 2013 at 16:11 #112734
Keith Long
Participant
@keithlong89920
MEW issue 41, page 24.

Keith
21 February 2013 at 16:38 #112736
Kevin Bennett
Participant
@kevinbennett25223
thanks Keith for that i have found it in that issue it looks like i have some reading to do and i will have to contact my friend who is a electronic engineer i am sure he will help on the electrical side of things

ty Kevin
21 February 2013 at 16:50 #112737
Les Jones 1
Participant
@lesjones1
Hi Kevin,
I managed to get a partial translation and they do use a microwave transformer with the secondary replaced with 2 (I think) turns of 25 sq mm wire. ( That would be 5.64 mm dia. if it was a single conductor.) For welding the mains is applied directly to the primary of the transformer. For annealing a light dimmer or drill speed controller is connected in series with the primary.

Les.

Edited By Les Jones 1 on 21/02/2013 16:59:47
21 February 2013 at 19:17 #112744
Kevin Bennett
Participant
@kevinbennett25223
got the drawings just need to convert to English, and what a performance to get winzip it also loaded 4 other program's and changing my browser Grrrrrrrrrr

thanks 4 all your help

ty Kevin
21 February 2013 at 19:27 #112745
Les Jones 1
Participant
@lesjones1
Hi Kevin,
Here is the result of using the google translate utility on the text from the schematic.

French

pour le transformateur.
transfo d'un micro onde enlever le secondaire le bobiner d'une spire de file de 25 mm Deux bouton poussoire, un switch 220v 3A et deux voyant 220V

English

for the transformer.
a microwave transformer remove the secondary winding of a coil of 25 mm Two queue poussoire button, a switch and two indicator 3A 220V 220V

25 sq mm is about 6.64 mm dia

——————————————————————————————

French

Modifier le potentiometre du variateur pour l'adapter au chassi de votre soudeuse.

Variateur electronique du commerce ou d'une lampe halogene ou perceuse electronique occasion.

Partie soudure

Parttie recuit

English

Modify the potentiometer drive to fit the chassi of your welder.

Electronic commerce drive or a halogen lamp or electronic drill occasion.

welding part

Parttie annealing
——————————————————————————————

Les.
21 February 2013 at 19:33 #112746
Kevin Bennett
Participant
@kevinbennett25223
thanks Les you are a big help

Kevin
22 February 2013 at 11:30 #112765
Ian S C
Participant
@iansc
The welder sounds interesting, there is a Microwave tranny, with the secondary removed sitting on one of my benches, I was fiddling around with spot welding, but have not done much with it lately.

The place that I get my blades will reweld broken bimetal blades at no cost, so I'll stick to that for now.

Ian S C
22 February 2013 at 13:17 #112774
Jeff Dayman
Participant
@jeffdayman43397
Before spending time and money gathering parts and building a welder, it might be wise to check price and availability on the ones at the link below. They are a nice unit, with a blade shear and a powered grinder included. These units are very similar if not a direct copy of the excellent welder/finisher units that were on the old DoAll bandsaws from USA.

Maybe one of the machine dealers could be persuaded to import them?

http://www.taiwantrade.com.tw/bandsaw/products-detail/en_US/550750

JD
22 February 2013 at 17:34 #112788
Speedy Builder5
Participant
@speedybuilder5
Ok, we now have a welder, or scarf and braze joints, but where do you all buy 'endless' bandsaw blades. My stock of car boot bargain roll is comming to an end.
22 February 2013 at 18:58 #112794
KWIL
Participant
@kwil
Cromwell Tools (and others) presently only showing completed blades but Knighton Tool Supplies show the standard Starrett 100ft coils in all sizes

Edited By KWIL on 22/02/2013 19:25:49
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