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How
To Build A Model
What
Is A Fibreglass Moulding?
Drilling
& Cutting GRP - Fitting Rudders & Prop Shafts
Painting
A Fibreglass Hull
Ministeam
Construction Tips
Building
A Steam Driven Thames Launch
A
Guide To Building A Steam Driven T.I.D. Tug
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Robin
Whitmarsh offers tips on building techniques for small hulls. Marine Modelling
- August 1999
Here
we have the finished steam yacht ready for its first proper sailing trials,
all varnished mahogany and polished brass glinting in the sun. Pretty little
thing I think you'll agree. Side and rear windows in the wheelhouse (which
has no floor) are unglazed, and together with an opening at the rear of the
raised part under the funnel, this seems to provide adequate ventilation.
However, I do plan to add some portholes to the superstructure sides at the
model's first refit.
Left:
This small model based on the Kingston Mouldings hull can be made both attractive
and stable, ideal for the kitchen table modeller who wants to try steam but
lacks space in workshop and car! Ministeam models aren't exactly beginners'
jobs to build, in fact in some ways they are really rather difficult, and
the main reason for this is of course the limited amount of space available
in the hulls. Because the Ministeam concept was new, or at least it was here
in the UK when I started to build the two boats described here, I had to sort
everything out for myself. None of the usual helpful feedback from Kingston
customers to draw on. The two models seen in these photos are two of the six
different Ministeam designs currently produced by Kingston Mouldings, and
of course neither is a scale model of anything in parlicular. As you can probably
work out for yourself, the grey one is a gunboat, and it measures just 520
x 170mm. The rather fancier example is what I laughingly call my steam yacht,
this one is 540 x 170mm, and both comply with current Ministeam rules. It
must be admitted that most models built for this class tend to look like caricatures
because of their rather dumpy proportions. This doesn't. necessarily mean
that they can't be attractive as well though, as I hope this little pair have
proved.
The
smaller the hull, the more difficult mounting steam Plants can be. For stability
reasons, we need to keep weight low, and prop shaft angles reasonably shallow.
My method enables everything to be fixed securely little more than the thickness
of an M4 nut away from the bottom of the hull. Shortened bolts have been screwed
into the nuts through a strip of 1.5mm ply slightly wider than the hull, and
a length of brazing rod soldered around the nuts to stap them turning. Of
course, the wood will char when you do this, so use scrap pieces of ply for
the actual soldering.
The
rear end of the SVS powered hull. The small Platform on the left of the bulkhead
carries the condenser. The battery box is on the opposite side, as this was
the only position where space could be found, but luckily it also balanced
the model, so that hardly any extra ballast was needed. You have to think
ahead all the time, and it was already clear that the rudder linkage was going
to cause a few problems, but more on this later. The main deck will end at
that rear mini-bulkhead, and a neat mahogany grating covers the linkage on
the finished model.
Right:
The finished engine mountings in the yacht hull. Bolt on the two strips of
ply as in the previous pic, then trim the ends very carefully a bit at a time
to fit the hull contours, until the position and sit of the steam plant is
exactly right. Then after cleaning all the metal with a suitable solvent,
apply epoxy around the nuts, with some additional small blobs on the ply where
it contacts the hull, reposition very carefully, and allow to cure. The bolts
can then be removed, leaving nuts and ply strips securely bonded to the hull.
It's then a simple matter to fill any spaces with P-38 or something similar,
using a scrap of wood to poke the filler into all the nooks and crannies.
Finally, sand away any excess filler, to end up with something as neat as
this, a solid ultra low-profile fixing, who could ask for more?

Left: This
is the front end of the hull at the same stage, the bit right in the bow is
a cradle for the SVS gas tank. Apart from the mountings for the steam plant
already described, almost everything else was fixed with cyano adhesives.
When everything seems to be in the right place, a thin brushed coat or two
of fibreglass resin secures all the joints and tidies things up, as well as
water and oil-proofing all the bare wood. Steam-powered model interiors can
get quite messy.

And
here's the steam yacht with all basic construction finished, and the sub-deck
sitting alongside. A tray behind the main bulkhead carries the 40 Mhz receiver
and two Multiplex MS12 servos, which are not exactly the smallest available.
As is becoming evident, there's very little unused space. Just remember that
the overall length of the hull is only 54Omm, or to put that another way,
slightly over 21".

After skipping all the early stages, which were much the same as the yacht
construction already described, this is the gunboat hull. Once again, everything
beneath inwale level has been given a thin coat of resin poked well into every
little nook and cranny, and making sure that any gaps between wood and hull
are completely filled. Do go easy with this, and use a decent quality brush
of the size you would normally use to paint a small model of this kind, not
some clumsy great thing.

The fact that no space is wasted is seen even more clearly in this view with
all the machinery installed, and the receiver aerial routed through short
lengths of plastic tubing under the inwales. Before finally gluing the deck
in place, I steamed the model like this, chugging gently up and down in the
bath, just to be certain that everything functioned exactly as intended, and
the model sat right in the water.

This is a close-up of the gunboat front end showing the gas tank and condenser
on little Platforms. You can also just make out the lugs soldered onto the
baseplate of the Cheddar Kompact steam plant, to make for a simple and neat
mounting onto those bearers described in the first couple of photos. Check
all runs for gas and steam pipes as you go, to make sure that it will be possible
to connect everything properly.

The finished
steam yacht model. As you can see, access to the radio, steam plant, servos
and linkages is far from simple once the deck is in place, though everything
can be removed for maintenance etc. if necessary, so it's absolutely essential
to sort out any snags at a fairly early stage. The rudder pushrod goes through
a small foam rubber block inside the coaming, and this prevents any water
running from the deck into the model's interior. Guess how I discovered that
little problem area.

And
here's the gunboat again, everything functioning perfectly ready for a run
on the bench, then another in the bath. Once that deck has been glued on,
access is greatly reduced, so don't even think about trying to sort out plumbing
or linkage problems after construction has passed beyond this stage.

Close-up of the gunboat rear end, and note that rudder linkage, I think I've
had more letters and phone calls on this subject with these little models,
than everything else put together .Yes, the rudder post is very close to the
hull side, but this is the straight ahead position, and as long as servo and
rudder arms are parallel like this, you still get equal rudder throws left
and right whatever their angle. With hindsight, the throttle servo would be
better behind the bulkhead, though this would complicate the linkage somewhat.
The action has since been improved by adding ball joints.
The
two models side by side, all basic construction complete, after a couple of
coats of sanding sealer. As you can see, I prefer working in wood to the styrene
sheet that seems to be more popular these days. Many people seeing these models
don't believe that they aren't all plastic, and I have to show them the underside
of the superstructures to convince them. Call me old-fashioned if you like,
but at least it won't melt. Those decks are done from individual planks with
tiny strips of black paper in between each one to represent the caulking,
the first time I've ever done this, but it is a little easier than it sounds.
I wasn't satisfied with the original deck on the yacht, so I sanded most of
it off and had a second go, which is what you can see in the photos of the
finished model.
The
finished gunboat, cheeky little thing isn't it? The addition of the capping
rail (cut from 1.5mm ply) makes the whole model look much more substantial.
All ventilation is provided by the unglazed windows in the wheelhouse. Some
fittings like the cowl vents were bought, but almost everything else on both
models was made from scrap plastic and wire. Both gunboat and yacht have an
impressive turn of speed, and are highly manoeuvrable looking just great on
the water, so perhaps they'll tempt a few readers to have a go at something
like this for themselves.

Same stage with deck in Place, see what I mean? Not a lot of room for fingers
now, these Ministeamers are small models. Both yacht and gunboat have planked
decks, and I found it much easier to do nearly all of this work before the
decks were glued to the inwales. The chord of the gunboat rudder had to be
extended considerably after first sailing trials to improve the model's manoeuvrability.
Ministeam steering course obstacles are usually pretty tight, and the models
have to be able to turn really sharply.
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