7
Sorting the wood in the kit by thickness
saves time. After selecting and cutting
what is needed, return the remaining
stock to the proper thickness pile. Don't
worry about using a piece for one item
that was intended for another. Model
Shipways supplies enough extra wood to
complete the model before running out.
5. Britannia Metal Fittings
Although most parts are wood, the kit
contains a small number of britannia
fittings. Before painting them, remove
any mold joint flash with a #11 hobby
blade, then file smooth or sand with
fine sandpaper. Clean parts in dish-
washing liquid and warm water to
remove traces of mold release agent
and any body oils your fingers have
deposited. Rinse thoroughly and allow
to dry completely before applying primer.
6. Soldering and Working
with Brass
Niagara
doesn't require a great deal of
soldering. However, here are a few tips:
Cut brass sheet and strips with a small pair
of tin snips or heavy scissors. Heavier
brass requires a jeweler's saw. After cut-
ting, smooth the edges with needle files
followed by wet-or-dry fine sandpaper
used dry. Cutting slivers from brass sheet
curls and bends it sideways. To straighten,
grip the ends with a pair of small pliers
and pull in opposite directions. Thin brass
sheets can be scored with a utility knife
and metal straightedge, then snapped off.
Use two or three light passes, cutting
against a maple chopping block, birch
board, or glass backing.
Drilling holes in brass with a pin vise is
a slow process. The solution is to mount
a handpiece for flex-shaft machines in a
hobby drill press. Several companies
manufacturer this tool and it is worth
the cost. When working with brass, use
a 1/4" or thicker piece of maple or birch
for backing. (Avoid softwoods, as these
flare the exit hole.) To prevent the bit
from wandering, mark the spot with a
small center punch. Lubricate the bit
with light oil and drill slowly to avoid
breakage. The brass will become hot, so
clamp the pieces to the drill press table
or hold them down with a wooden
stick. Use a speed reducer to keep rpms
under 2,000; otherwise, excessive heat
buildup will break a small bit.
Solder
: Until recently, modelers used
pure silver solder to avoid the corrosive
qualities of lead in soft solder. Today,
many solders are lead free. They're com-
posed of tin and antimony, are strong,
and melt at less than 450º F. Some
brands are mixed with 3% or 4% silver,
but still melt easily. Consequently, no
reason exists to use pure silver solder
(melts at 1300º F).
Flux
: Purchase pure solder and buy flux
separately for additional control. Paste
fluxes apply more precisely than liq-
uids, which run to all the wrong places.
Soldering
: The key to soldering is keeping
the brass clean. Use a solvent, lightly
sand, or both. Once the parts are cleaned,
don't touch them. Your fingers will leave
greasy spots. Soldering is easy if your
work is set up properly. First, immobilize
the parts in a fixture or other holding
device, then add just enough flux to the
joint to do the job. Remember, solder
flows where flux is applied.
Next, cut a small piece of solder and lay
it on the joint before heating.
Experiment with various sizes to learn
how much solder it takes to just fill a
joint. The joint should look like the real
thing, not a glob of fillet. Heat the joint
with a small torch or pencil soldering
iron. This sequence is important. The
larger the parts, the longer it takes to
heat the brass and melt the solder.
Remove excess solder with needle files.
LOOKING FORWARD
CAPSTAN AND SKYLIGHTS
