Sunday, April 26, 2015

Mending a saw blade

After breaking the saw blade for the mulesaw, I tried using one of the other blades that I have.
Two blades have a different tooth configuration, and it became obvious, that this configuration is not perfect for wide hardwood trunks.
I decided that I might as well try to see if I could repair the blade, since I don't know where I can buy a new one. And if the repair job didn't work out, It would be sort of a Life of Brian thing: You come from nothing and you're going back to nothing - what have you lost? Nothing. (Except a bit of time and a few welding electrodes).

At first I straightened out the broken pieces since they were a bit bowed on the ends.

Next I ground the broken edges to prepare a groove when they were fixed in their correct position.

To make sure the blade was properly aligned, I clamped the pieces to a piece of wood with a straight piece along the back of the blade.

I found my old portable electrode welding machine (ESAB Caddy) and some welding electrodes.
My go to electrodes for this type of repair job is ESAB OK 53.05 There might be some more correct types out there, but I always have some of the aforementioned electrodes on hand, as they are really versatile.

The welding could have looked better, but welding thin steel with an electrode welder is not easy. At least not when you have an electrode of 2.5 mm in diameter which is better suited for thicker material.

After welding the blade I used an angle grinder to clean up and level things out on the blade.

I tested the blade, and it went OK for about 8", then it snapped again, but I could see that my welding wasn't very good at that spot, so I just welded it again, and then it held.

So all in all the project was a success.

The blade on the workbench.

Broken edges ground to form a groove.

Holding the blade in position.

Welding complete.

Welding ground with an angle grinder.

The mounting system of the blade.

Blade inset in the tightening/holding device on the saw frame.

A whitebeam plank sawed with the mended blade.
Saw is shown to give and idea of the size of the plank.

6 comments:

  1. Nice fix. I think even I could sharpen this blade without glasses. Is there much set to this blade?

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    Replies
    1. Hi Ralph.

      The set is approximately 1/16" to each side. So it is a pretty decent set.
      It has to be, because traditionally you process the trunk while the wood is still wet. Plus if there is not enough set, the blade has a tendency to wander of.
      Brgds
      Jonas

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  2. Awesome! Glad you were able to salvage this blade and get it back up and running. Wow, that's a pretty wide plank.

    Greg

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    Replies
    1. Hi Greg.
      I don't know where I should get hold of another blade like this, so I had to try fixing it. It doesn't look super, but it works. That's the important thing :-)
      I'm glad you like the planks.
      Brgds
      Jonas

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  3. Man you did a fine job. What a board !!!!!!!!!! I only wish for tinber like that.

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    Replies
    1. Hi Robert.
      Thanks for the nice comment.
      I was about to suggest that you could come by for a piece of lumber, but I checked your profile, and it looks like you live in Tennessee, so it might be a bit too far :-)
      I am sawing the boards for a friend. He has requested all of them to be 2.25". I would have made some of them 5/4" or 4/4", It would make a really nice looking chest that way.
      Brgds
      Jonas

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