Brazing a new pricker needle into an Optimus 111 rack.

Trying to braze a new section of guitar string wire onto the pricker rack of a Optimus 111 is difficult. At best, the wire quickly oxidises and the braze filler will not wet onto the wire. At worst the brazing torch will easily burn through the thin wire.

This technique works for me, and others may find it useful.

The only unusual tool you will need is a small laboratory scissor lift to place your soldering board onto, and these are available cheap of the internet.



Select your guitar string and make sure it fits through the Nipple jet hole. Then clean and flux the end of the wire and put it to one side. Melt a very small piece of silver brazing rod on the soldering board, and when it is a red hot molten ball dip the fluxed end of the wire into it and let it solidify.



Then file flat the top of the rack, and then clean, flux and 'tin' this top surface with another small piece of silver braze.

Set up the brazing rig so that the wire is suspended above the rack



and then heat the rack at the bottom and wait until the top gets hot enough to melt the braze on the rack surface, taking care not to melt the braze ball on the wire.

When the brazed rack surface melts keep the torch flame on the rack with one hand and raise the scissor jack with the other hand until the top of the rack and the wire braze ball meet. When fused together remove the heat.







Clean up any excess braze from the sides and cut the wire to length



Clean the wire and make sure it slides easily into the nipple hole, before inserting the rack and nipple into the burner.

Check all is well





and test fire.

 

@Twoberth
Great technique you’ve devised there Duncan

John

 

Thanks John, it works well.
Once you have the scissor lift it is an inexpensive technique to practice on scrap

 

Good technique!

Tony

 

Thanks Tony.

 

Very clever use of a scissor lift for precision soldering.
I made a note to myself of this.
Thanks for sharing a great idea.

 

@Knee

 

@Twoberth Excellent work there, and a brilliant well thought out technique.
I really enjoy these posts where a part or anything to do with a stove or lamp or anything else which would have been written off and discarded but repaired to do its job as good as it once did, well done there

 

@mr optimus Thank you.

 

Great tutorial. Thank you!

 

@TSPORT Thanks