Building Katie and other model boats

Sunday, January 22, 2023

Bella - Making the hull

The frames and keel were initially glued together using "superglue" in two stages. the weights holding the frames down on the worktop, which is flat and the square ensured the keel was at 90 degrees.

The panels were added one at a time and tacked in place using superglue. One tip I picked up from a German blog, glue some glass paper to the pads on clamps, then they don't slip off. Its important to ensure the side panels are pushed right down into the slots at the tops of the frames. The bottom panels needed a very fine trim to fit. The slot for the keel needed to be widened due to the modification/increase in thickness made the keel/fin.

Generally the hull is ok after being removed from the baseboard. At the bow the chine joint hadn't glued, so this needed attention with a couple of clamps and glue. Think a small piece of glass fibre tissue on the inside face with increase the strength in this area and stop the joint breaking. The plan is to create a epoxy fillet on the inside of the chine joint.

The bow is very fine and the wood is end grain, so vulnerable to damage. So will look at finishing this square and then adding a small hardwood section to prevent damage to the hull.

A short piece of 3mm thick acrylic has been fixed near the bow. This is for the eye that the jib will attach to. The eye has a M3 thread and once the deck is on, this will be drilled and tapped to provide a secure fixing.

Bella - Making a start

Most of the parts are made from 3mm plywood, including the keel/fin. Not only is this a little thin but lacked any aero profile, so I decided to glue additional 3mm ply on either side. This will increase the strength and also enable a simple profile to be created, which should enable to boat to perform better, especially when sailing to windward.

The ballast weight is provided in the form of two castings, these are made from some form of steel, so will need to be well finished to stop any corrosion. On closer inspection these were not identical and also the fixing holes were not equally positioned, so this meant that there needed to be some adjustment.

By opening up the holes it was possible to use a piece of 4mm dia brass to line up the two halves. The plan is to fix these pieces to the keel using some West Epoxy and threading the bass rod to clamp them in place. Some shallow holes were drilled on the inside face and also through the keel for the epoxy to flow, to ensure the weights are secure. There will be a need to fill/smooth the final shape, as well as clearing some of the white coating, so the epoxy will bond directly to the steel.

The rear frames are glued together in a sub-assembly, before an initial dry fitting for the rest of the frames.

Aeronaut Bella

This is a well known kit and there are plenty of examples to be found via a search of the internet. This kit was acquired via a friend from a person who had bought it but it was never started. The original purchaser had also obtained two servos and had kindly printed off the English version of the instructions.

Sailing boats - aeronaut model making (aero-naut.de)

Although Aeronaut is a German company, the website has an English option and its also possible to download the instructions for any of the models, which is useful to assess the suitability of any kit before purchase.

The general quality of the kit is excellent, as are the instructions. The wooden parts are laser cut. What appealed about the kit was its the good aesthetics, so the aim is for it to sail well and for it to also make a good display model. The first task was to give the mahogany sides a couple of coats of thinned varnish. The laser cuts can just be seen in the photograph.

Suhaili

Emma was the first boat that was built, using plans from Gary at Bearospace and certainly recommended.

BOATS (bearospaceindustries.com)

Looking at the design of this boat it became obvious that the general proportions were similar to Robin Knox Johnson's Suhaili. A second Emma hull was built but the deck layout and rig was changed. Although not meant to be an accurate scale model, it aims to give the impression of Suhaili while sailing.