Hull restoration completed – August 2017

THE STEAM BENT FRAMES

THE WOODEN FLOORS

THE STEAM BENT FRAMES

Almost all the steam bent frames in the yacht were either cracked or rotten in at least one place when Armide arrived at Classic Works. The worst areas for cracking were aft where the hull curvature was the greatest (and the frames had been forced) and the worst areas for rot were under the galley, the bathrooms and low down in the bilges.Initially it was hoped to save about 30% of the steam bent frames but in the end it was deemed to be quicker to change them all rather than to have to scarph into the old ones in many areas.

The bilge stringers were cut and removed in sections so that the frames could be accessed. The copper roves were ground off, the nails knocked out and the frames then prised away from the hull in small sections of between two to four pairs.

With the frames out, the hull planking could be repaired as required and in order not to have alignment problems with the new fastenings, all the old rivet holes were sealed up completely with teak dowels set in epoxy.

Any planks due for replacement were left untouched at this stage so that there was no risk of duplicating tasks and they could also act as a former for the curves of the new frames. Likewise, the grown frames and the remaining steam bent frames, although in bad condition, all helped to keep the hull in shape for the new frames.

Once the old frames were out, the hull planking was restored, primed and painted so that each area was ready to accept the new frames.

Green, knot-free ash was sourced from a timber yard in the middle of France and this arrived in log form, sawn through and through. Frame by frame the timber was cut from the ash boards and then machined to the original dimensions plus 10% (because the original sections were deemed to be too light) thus giving a finished siding of 60mm and moulding (thickness) of 45mm. The heels were shaped from a thin plywood template to slot into the wooden keel and then the new frame was ready to be placed in a steam oven.

Steaming lasted for up to an hour and a half and upon removal each frame had to be passed under the shelf and wedged in place within a couple of minutes otherwise they would have lost their suppleness. The new frames then remained wedged into the hull, between grown frames, for at least 48 hours so that they could take the required shape with the minimum amount of spring-back.

Then, once all the wedge clamps were removed, each frame was dry fitted prior to priming, drilling off and riveting with copper boat nails and roves. All frames were bedded onto the hull planking with a mixture based on linseed oil and putty.

In areas where copper riveting was not possible, such as behind the shelf and alongside the wooden keel in the bilges, the frames were secured with 6mm silicon bronze coach bolts.

The frames in the stern areas of the yacht, where the curvature and twist were greatest, were epoxy laminated from wide but thin (3mm) oak strips. This was to avoid the cracking problems from over-forcing of the steam bent frames that had occurred when the original frames had been placed in the yacht.

In order to give the hull extra stiffness when the yacht is lifted out of the workshop and in the future, an extra (third) steam bent frame was added between the grown frames at the two sling positions forward and aft. These extra frames are designed to reinforce the hull at the turn of the bilge so they go up to deck level but do not go all the way down to the wooden keel.

With time, the ash will slowly dry and that action will greatly add to their rigidity and that of the hull.

THE WOODEN FLOORS

Once the majority of the steam bent frames had been replaced, the next step was to repair and/or replace the wooden floors that secured the lower sections of the grown frames to each other across the wooden keel and to the wooden keel itself.

The oak floors, original from 1938, had been installed with a high degree of craftsmanship and the fit between them, the frames and the wooden keel was very precise.

Conventionally built floors, either in wood or metal, secure frames to the wooden keel and then the lead keel is independently bolted to the yacht through the wooden keel. However, unusually on Armide, the floors had been through-bolted to the lead keel as well as to the grown frames.

Although unconventional, this construction method had worked even if there were signs of movement in this area of the hull and she was leaking at the garboard seams when she arrived at Classic Works.

Fortunately, the original keel bolts had been in bronze so the floors and the wooden keel had survived relatively undamaged (from corrosion) despite the floor to frame bolts being in galvanised steel.

Each floor (there were 23 in total) was taken out, cleaned up and left to dry and stabilise. They were then repaired by cutting away splits and rot and gluing in inserts with thickened epoxy resin. In the mean-time the wooden keel was locally treated and repaired as necessary.

Floors that were considered to be too damaged to be worth repairing (mainly aft and forward and at the engine beds) were used as templates to make new floors in oak.

Whilst each floor was removed they were temporarily replaced by heavy plywood floors which enabled the works to continue on other floors and the restoration of the grown frames to start.

Then, once all frames were completed, the floors, with their limber holes cleared and repaired, were re-installed and bronze bolted to the new grown frames.

New bronze keel bolts were fitted to secure the lead keel to the hull, passing through the wooden keel and into the fully restored, original, wooden floors.

All wooden floors were reinforced by the addition of new bronze plate floors and these will be described separately, to follow.