MadModder

Gallery, Projects and General => How to's => Topic started by: ozzie46 on July 21, 2010, 04:14:51 AM

Title: Repairing Band saw Blades
Post by: ozzie46 on July 21, 2010, 04:14:51 AM



     
    I tore some teeth off of my 4 x6 band saw and really didn't want to go buy another one as I had 3 broken blades in the shop. While perusing DrJs' Site,


http://dr-john.org/

  he showed how he repaired his saw blades so I copied the idea.

   I grabbed some angle iron and milled a step on it and then milled a cut out in it. The step is to butt the blade up against and the cut out is so you can heat the blade.

  (http://i661.photobucket.com/albums/uu334/ozzie46/DSC02828.jpg)

  I mounted the angle in a vise and then used my belt sander to grind a scarf joint on the broken ends after they had been ground square. the scarf joint is about 1/8" wide.

  I then used miniature vice grip pliers to hold the blade to the angle iron with the joint over the cutout area. I fluxed the joint and then cut a piece of silver solder and laid in on the joint. Then I heated it till the solder flowed through the joint.

   This is the torch I used. It uses lighter butane as fuel.

  (http://i661.photobucket.com/albums/uu334/ozzie46/DSC02830.jpg)

   This what it looked like after cleaning up with a dremel with a drum sander on it.
    Be careful and don't take to much off. Just get to real close to the original blade thickness.

   (http://i661.photobucket.com/albums/uu334/ozzie46/DSC02829.jpg)

   I tried it out on the bolt that ripped the teeth off the other blade and it work flawlessly.

   Thank you DrJ.


  If you have broken blades don't throw them out try this. If I can do it you can to as I am really a novice when it comes to silver soldering.


   Ron

 
Title: Re: Repairing Band saw Blades
Post by: atwatterkent on July 22, 2010, 11:30:40 AM
Here's another example of the same solution using a piece of 4" chanel with a slot for 1/4"-3/8" and the other side takes 1/2"-3/4" blades. The gap is 1" wide and 1/2" deep.:
(http://i204.photobucket.com/albums/bb185/atwatter/lathe%20projects/my%20shop/my%20projects/bladejig3.jpg)
(http://i204.photobucket.com/albums/bb185/atwatter/lathe%20projects/my%20shop/my%20projects/bladejig1.jpg)
(http://i204.photobucket.com/albums/bb185/atwatter/lathe%20projects/my%20shop/my%20projects/bladejig2.jpg)
I use this jig to demonstrate blade repair in the local for the local jr. college machine shop classes.
Title: Re: Repairing Band saw Blades
Post by: ozzie46 on July 22, 2010, 11:49:20 AM



   Very nice jig.  Thanks for sharing it.

   Ron
Title: Re: Repairing Band saw Blades
Post by: Bernd on July 22, 2010, 07:58:28 PM
Unfortnatly that saw blade in the first pic isn't going to work to well.  :clap:

Anybody spot why?

Nice work on that jig by the way. Very clean. :thumbup:

Bernd
Title: Re: Repairing Band saw Blades
Post by: ozzie46 on July 22, 2010, 08:46:51 PM


   I didn't at first, but I do now. Bacards and forards.    :lol: :lol: :lol:

  Ron
Title: Re: Repairing Band saw Blades
Post by: atwatterkent on July 22, 2010, 10:08:03 PM
I wondered if anyone would notice. The class demonstration used two short pieces of saw blade without reguard as to the direction of the teeth. With a class of 14, Machine Tool 1 students, none of them noticed.
Title: Re: Repairing Band saw Blades
Post by: dsquire on July 22, 2010, 10:27:43 PM
atwatterkent

I noticed that earlier but didn't say anything because if one looked at all the pictures you could see that it was only a short sample piece to show how it fits in the jig. The only way one could make a joint like that in real life would be to use 2 separate pieces of band saw blade with 2 welds to make 1 blade.  :ddb: :ddb:

Cheers  :beer:

Don

Title: Re: Repairing Band saw Blades
Post by: atwatterkent on July 22, 2010, 10:46:59 PM
One other thing I would offer as a suggestion is that MAP gas with a standard adjustable propane torch head is a viable alternative to Butane. Propane won't work, not enough heat.
Title: Re: Repairing Band saw Blades
Post by: Bernd on July 23, 2010, 08:19:49 AM
Hey Don. Not fair. I didn't look close enough at the third pic to see that is was only a short piece. :doh:

Darn. Caught with my pants down again.  :bang:   :lol:

Bernd
Title: Re: Repairing Band saw Blades
Post by: fatal-exception on August 19, 2010, 01:46:17 PM
I like the jig.

I've migged bandsaw blades back together using short hot bursts, like many little tacks. Not sure how it affect the temper around the weld, but they seem to hold.

Paul
Title: Re: Repairing Band saw Blades
Post by: ozzie46 on August 19, 2010, 04:16:37 PM


  Thanks for looking in Paul, and welcome to the group.

   Ron