Folds
Folds are indicated on the etches by half-
etched lines. Unless stated otherwise, all
folds are made at 90° with the half-etched
line on the inside of the fold. Most folds
may be made by holding the larger part of
the workpiece in the fingers or, for smaller
items, a hand vice or similar clamp, and
then driving the fold from the smaller part
either by using smooth-jawed pliers or by
turning it over against a smooth, flat, hard
block of material such as hardwood, metal
or tufnol. For longer folds the workpiece
may be clamped between two flat, straight
edged pieces of similar material. Special
folding tools or bending bars are not
nec essary, though of course you may find
them useful if you have them.
Whichever way you make a fold, try not to force its location or direction, but let the
brass bend at its weakest point as determined by the centre of the etched fold line.
This should result in a correctly positioned and symmetric fold as shown in the
diagram.
The act of making the fold will work-harden the metal along the line of the fold and
may even, especially with a lighter etch, cause it to yield on the outer corner of the
fold. Try, therefore, not to work a fold unnecessarily once made, as it will become
increasingly brittle and prone to breakage. In general, folds are reinforced with a fillet
of solder but this is explicitly dealt with in the instructions for each component.
Soldering
We use Carrs 145° wire solder with Carrs Green Label liquid flux, except where
stated otherwise.
Flux can be applied to the workpiece using either a brush or a pointed cocktail
st ic k. It may help to reduce the surface tension of liquid flux, for example by
adding a drop of washing up liquid or ox-gall. The soldering iron bit is wiped on a damp
sponge, and then momentarily dipped in flux, before each use. A small amount of
solder is picked up on the bit and the bit applied to the workpiece, holding it there
until the solder 'flashes' into the joint; we are using relatively thick material so can
afford to linger with the iron and get plenty of heat to the job.
Flux residues should be neutralized and/or cleaned off after each working session.
Green Label flux may be rinsed away with water; a little added citric acid will
neutralize it. Liquid or paste fluxes can be washed away either with a proprietary flux
cleaner or a 50/50 mix of methylated spirits and water.
General Notes
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(c) PenBits Model Railways, All Rights Reserved
04/05/2017