The Naiad Voyages

Mark Austen

2016.12.16 - Laminating the Rubbing Strakes - Part I

I have to confess that I've not been looking forward to this task and have put it off until I was certain in my own mind that I had a way to laminate the timber with a reasonable chance of success. There are just too many things that could go wrong if the task were not thought through properly.

The problem is that not only are the laminates not single pieces the correct width and length but some of them are not the correct length either. Also there is nothing to which the laminates can be clamped meaning that they will have to be screwed to the hull whilst the epoxy cures. At first glance this requires about seventeen hands to make it work and I only have two. So I needed a plan to enable me to get the laminates screwed to the hull without them falling all over the place at critical moments.


The first thing to do was to ensure that I had a long enough table upon which to epoxy the strakes. The second thing was to arrange the pieces so that the outer laminates are full length and any that are not are in the inside of the resulting timber. You can see the laminates arranged here. The third thing was to cut ten 12" pieces of wire and two pieces of plastic just longer than the strakes.


As much as possible the shorter lengths were arranged so that the joins did not overlap.


The laminates were covered in epoxy and assembled into one piece and then wrapped up in the plastic.


Five of the pieces of wire were used to tie the bundle together keeping all the pieces from falling apart and the plastic from coming off.


A large cramp was clamped to the outwale as you can see here and used to hold the forward end of the bundle of laminates whilst the screws were put in place.


Just one screw and the forward cramp held the piece in pretty much the correct place obviating the need for fifteen of the seventeen hands initially required.


This is why the shorter lengths were put on the inside of the timber. The full length outer and inner pieces will serve to hold this join together properly. Screws were put in at 6" intervals and at each position, before the screw hole was drilled, two pieces of wood were clamped to the bundle of laminates. This made sure that the top and bottom of the bundle were aligned. The top piece of wood overlapped the deck and this was just to make sure that the top of the bundle was in line with the deck. Then the hole was drilled and a piece of plywood screwed to the timber, through the hold and into the outwale to hold the laminates together.


After a few screws had been put in place the forward end of the laminate bundle was pulled hard against the hull using a string as shown.


The last screw position has two cramps. The aft one lines up the laminates and the forward one clamps a piece of wood to the deck and pushes the laminate bundle downwards since at this point it is trying to rise up due to the curve.


And here is the result of the morning's work. I'm pleased to say that nothing went wrong, in fact, everything went exactly to plan.

The result will not be perfect but it should be borne in mind that the rubbing strake is a sacrificial piece of the boat. Its purpose is to take the knocks and bumps instead of the hull. Making it pretty and out of an expensive piece of timber is a waste of time and money. That isn't to say that it should be any old piece of timber put on any old how, but if it is less than perfect, and this one most certainly is, it is not a drawback.

So, lunchtime and then the other side can be done.


And there we go. I'll see how those are in a few days time when the epoxy has cured sufficiently.