Friday, April 29, 2022

Needle Chisel Repairs Part I of II


Repairing a model tackmaking tool is a great chance to see how it was made as well as the more obvious 'how to make it better.'  I busted two of my needle chisels back in January working on the TwentyMule.  Documenting how I fixed them will be the subject of two posts.  Each tool is different in its construction and repair.  These are largely pictorial journies; the photos speak for themselves.

The needle chisel is a miniature chisel.  I make them from a needle and a paintbrush handle.  I use them for everything from slits to cleaning, from braiding to inserting to manipulating.  I have 5 needle chisels at this point in time [2022], ranging from extremely small to fairly large.  For the record, the broken ones were my smallest and my middle-medium, this last being my oldest and most useful, called the Red & Black in my tackmaking notebooks.  The name refers to the braided handle covering.  Its repair will be the subject of Part II.  Sometimes they don't have covers, as the lower, smaller shows.  We'll look at that one first : "Smallest."

Here's its problem.  The blade, part of a needle which has been sharpened into a tiny chisel, was soldered into the tip of the ferrule.  But that join wasn't strong or secure enough to withstand repeated force and sidewise thrusting -- or whatever caused it to break.  I break my tools multiple times, until I build them strong enough.  I really manhandle tools!  But in both these cases the chisels had been with me for years.  I think the TwentyMule really pushed me to mass-produce in a few places.

I suspect the ferrule was aluminum.  Aluminum won't solder, which would contribute to the original weakness.  I should have used a steel ferrule, but those are hard to find.

First step: Decide that, after all, an aluminum ferrule is not what I want.  (Also realize the handle is long enough to stand losing a little.)  I broke the ferrule off --- possibly it broke by itself -- and discarded it.  I got out some brass tubing and started opening up one end, for a ferrule replacement.  This is accomplished by haggling with the nippers, X-Acto and files.

This is where I have filed down the handle to a tapering point.

Here the magic is starting to happen.  I'm making a ferrule of my own.  Fitting it closely to the wood handle is taking a lot of filing and plier-work, squeezing, bending and rolling.

This very revealing picture shows something no one has seen yet:  my soldering station.  The yellow sponge is moistened and used to clean off the soldering tip.  The dark-amber, waxlike substance is flux, used in soldering.  The shallow plastic lid holds little snippets of solder, which I have prepared myself, by hammering and cutting.  The brass tubing can be seen in the upper left.
What the picture does not show is my vise, which holds the subject in place during the procedure.   (Watch yer spelling!  A vice is not a vise... well, not usually!)

More magic:  an inner, smaller sleeve (or shim) piece of brass tubing will hold the needle tip.  When the smaller tip is affixed to the needle chisel, I slip it into the outer tube and keep soldering.

The pictures don't show the intermediate step of the smaller tube.  But it's in there.  The whole end of the outer tube is filled with solder.  That baby is IN there!!
A closer look (it's cool now):

When things are cool, next comes a LOT of filing of the end.  I prefer a pointed, tapered tip, for reasons of handle-ability and grace as well as beauty.  The pointing makes the needle stronger since there is less sidewise stress on its base.

Here I've filed it even smoother and pointy-er.  So smooth, in fact, you can't detect the difference between solder and brass.  Symmetry is important in this step.  If the needle is not straight (and it isn't), this asymmetry is balanced by a bulge in the taper.

Done!  Smallest Needle Chisel, which has never had any braiding of its own before, gets a beautiful 'holding' button.  Oh, sure, in the course of time, that bare brass will corrode the leather.  But right now I'm not worrying about that.

When I do get around to worrying about corrosion, a piece of silver tape between leather and metal should solve it.


  1. The tool that you use for clamping things in is only a ‘vise’ in the US - in Aus & UK etc, English, it IS a ‘vice’ 😊

  2. Thank you, eh, well, even the natives have trouble with the language. If the context is good, hopefully an overseas translation will come through.