Tom Sherrin is a Poole Harbour Pilot Launch, designed in the 1960s by John Askham of Bembridge, Isle of Wight, and built by James and Caddy of Weymouth. She was launched in 1970, and served as a pilot cutter until 1988, and was subsequently sold to the Harbourmaster in Alderney, for use as a pilot boat, work boat and occasional push tug. In 2000 she was purchased by the MVS (Maritime Volunteer Service) in Poole. She came to Boathouse 4 in December 2015.
There is still much to be done for her restoration (lots of pics on this hyperlink), and my first task on this boat was a minor repair, requiring a ‘graving piece.’
Rather than replace an area of minor damage, it is often possible to make a repair by fitting a graving piece. This is a small piece of wood, often diamond-shaped, or an oblong with pointed ends, laid into the damaged area, once the damaged timber has been removed.
A graving piece, often nicknamed ‘gravy bit’, is also known as a Dutchman repair or just Dutchman – one famous small yard, Hilliards, uses the nickname ‘little boy’. Of course, the reference to Dutchmen and little boys, is to the apocryphal little Dutch boy who put his finger in the dyke to stop a leak.
After deciding how much timber needs to be removed, the graving piece is made, just big enough to cover the damaged area.
The graving piece is cut out of a piece of wood that is thicker than the depth of the repair, making it both stronger and easier to handle. Once fitted it is easy to remove excess thickness with a plane or a sharp chisel.
Next, the graving piece is put in place on the plank, and carefully scribed around using a knife to ensure that the scribed lines perfectly define the shape of the graving piece. The damaged area is now chopped out.
The graving piece is then glued into place, and often screws or other fixings are added once the the excess thickness has been removed to make the patch repair level with the surrounding wood.
On the keel of Tom Sherrin, just aft of the bow, a knot in the oak had split open (probably due to the drying out of the boat). The hole created extended right through the four inch thick keel.
A two part Dutchman repair was agreed. This is known as a ‘top hat’ repair, because the outside graving piece overlaps the deeper part, like the brim of a top hat. This has the advantage of the water pressure pushing the outer part against the inner part, making a sounder repair.
My fellow student, Tom, did a one piece repair to the smaller defect on the other side.
As I will elaborate upon in my next post, there is more than one way to skin a cat, and that’s certainly the case here. As the Head of the College said, “In a commercial yard, you’d just fill the hole with epoxy and wood fibres, and have the job done within an hour or two.” This, after I had spent a few days doing this repair! Never mind, it’s always good to learn the gold standard techniques, and gain experience and skills in doing that … you can learn the short cuts later.
It’s like that in medicine and, no doubt, in other professions too. As medical students, we learnt how to ‘clerk’ a patient by taking a full history and performing a full examination … taking nearly an hour at first to do so. On qualifying, we were clerking in hospital admissions in a fraction of the time. A few years later, it was 10 minute consultations in General Practice!
I sometimes feel frustrated at how long it takes me, to complete a job on a boat. The others feel the same. Worth remembering then, that everything we are doing is for the first time; how one does speed up after the first time of doing something new; and that no skill comes without repetition and experience.
My next ‘gravy bit’ won’t take me half as long!