[ARC5] BC-AN-229 Follies, part 2

[AKLDGUY .]

When I worked in the telecommunications industry, we used to open soldered
brass and tin cans up to 6 or 8 inches per side. The solder was covered by
paint. Here's how we did it:

Clamp the can in a vise with base upwards. Connect a strong wire from one
mounting bolt to another so as to form a handle that can pull the base
upwards.
This might involve winding the wire around one mounting bolt and tightening
down its nut, then doing the same on the diagonally opposite corner.

Heat around the soldered perimeter with a propane gas torch, brushing away
the melted solder and paint with a wire brush. Don't linger too long with
the
flame in one area. When all the solder/paint are gone, pull upwards on the
handle. If part of the can refuses to budge, play the torch on that area
and keep
scrubbing it until the base and internals can be lifted out.

We used to do that several times a week with delicate assemblies that
included
crystal filters. The paint would get badly scorched but we would grind it
off with
a bench mounted wire brush.

After repair, resoldering would take place with a large soldering iron
working
around the perimeter. The entire assembly would then be resprayed with
paint.
They looked as good as new after this treatment.

The secret of success is that the propane torch quickly heats the solder so
it can
be entirely removed with the brush. The aim is not merely to melt the
solder but
to remove it entirely so it cannot solidify while working another
area. Once the
solder is gone, nothing holds the base to the can **because no solder exists
between the mating faces of the can and base**. It is all external.

A soldering iron is far too slow for unsoldering. I think the same
technique could
be used on the much smaller cans currently being discussed because they seem
to be of exactly the same construction.

73 de Neil ZL1ANM