Wednesday, July 25, 2012

How To: Silver Brazing Threads To The End Of A Steel Knife Tang.

TANG EXTENSION

#1. File a “V” notch in the end of the tang with a triangular file and file or grind one end of the threaded piece to match as perfectly as possible. Make sure the area and surfaces to be joined are clean, and free of scale and oxidation.

#2. Use hard grade/high temp., silver solder granules. The granules are made by fluxing pieces cut from sheet or wire solder and then heating them with a torch until they melt and pull into tiny spheres. The granules can then be transported with a stainless steel soldering pick. This is done by melting flux on the tip of the pick and the granule simultaneously and using the tackiness of the flux to hold the granule.

#3. Flux the joint and position the granules.

#4. Heat the steel, (tang and threads), evenly with a torch until the solder flows into the joint by capillary action.

#5. Pickle and wire brush the area for clean up. Check the seam and file off any excess solder if needed.

For general information on brazing and the strength of silver brazing, click here.

For further study, also see what MS Wayne Goddard has to say, more information.

5 comments:

  1. very cool Tai,

    Then do you find the right die that fits the threads and then tap into the piece(fitting) you made?or do you already know the size when you start?

    ReplyDelete
  2. Jeffro, it helps if you know what size it is first, but you could do it either way. On this particular example, I had a piece of all thread and matching coupling nuts. The coupling nuts are nice because they have more depth than a regular nut. I’m going to counter sink the nut then put a decorative end cap on to cover it all up. On Wayne’s example, he silver brazes a nut to the piece he uses to cover the end. Another method is to tap threads into a hole in the end piece with a bottom tap, so the threaded piece doesn’t show.

    ReplyDelete
  3. Tai- great info! Thanks.

    Why make the solder granules instead of using a brazing rod?

    ReplyDelete
    Replies
    1. I think the granules are easier to control, more precise with less waste,… but mainly so as not to disrupt the joint or jar the threaded piece out of position. However, some people find it easier or prefer to use a wire or rod. If that’s the case, use more of a “U” notch to hold the threaded piece in position. Either way is fine.

      Delete
  4. Hi very good post, got a very good information about brazing. Thank you for the post.

    ReplyDelete