This afternoon I decided to start on shortening the scales on this Bengall shortie.
First I very carefully drilled out the "head" of the pivot pin using a 1.6mm drill bit in a Dremel mounted in a Dremel drill press. I have designed and built a variable speed control so that the dremel can operate at well below its normal minimum 10,000rpm. The drilling was also done with a water/soluble oil emulsion for cooling and lubricating. The plastic scales can easily be melted when drilling out a pin. Once the head had been drilled out, it was fairly easy to tap the pivot pin out using a jeweller's hammer and an old 1.5mm drill bit as a pin punch.
I managed to save the pin collars for refitting. This Bengall is fitted with double collars on each side of the scales. The inner collars are slightly smaller than the outer collars. There are no washers between the blade's shank and the inner surface of the scales.
With the blade now free of the scales, I was pleasantly surprised that there was very little oxidation on the shank in the pivot pin area. Here it is after just a wipe clean with toilet paper.
The pivot pin hole had a fair amount of gunk in it so I removed that with a toothpick and turps. To clean the shank and tail up, I started with 400 W&D followed by 600, 1k and 2k. This was finished off with an Autosol polish. I also further cleaned out the pivot pin hole with acetone and a toothpick wrapped in toilet paper. All looked good.
I then filled the now clean pivot pin hole with epoxy weld and let it set. Once set and cleaned up, I drilled a new 1.6mm pivot pin hole in the epoxy as far from blade's point as possible. This mean that the blade's point will move away from the wedge as the epoxy wears.
Tomorrow I might start working on shortening the scales and will report back in this thread.