Rudder Repair – Update

Based on the 3D scan and a thorough assessment of LUCIE’s hull the team concluded that the rudder needs some work. It has warped over the whole length, resulting in an S-shape of +/- 8mm on the trailing edge. In order to fix this issue we discussed various options and eventually decided to replace the current rudder (solid mahogany glassed over) with a new rudder made from marine grade Merranti plywood. We had good and intense discussions with the Naval Architect Jacob Vargish and arrived at a construction design that is very strong, guarantees long time stability of the shape and best of all allows for the new rudder to be built while LUCIE rests on her trailer. This new design will later allow to remove the rudder bade in case access to the rudder post, stock or blade should become necessary.

The new design will be build from four lifts of plywood with a very strong one piece G10 trailing edge (up to 5″ deep, 1/4″ heavy, trailing down to 5/64″), glassed with two layers of by-axial 10 oz glass and held in place to the rudder stock with 7 stainless steel drifts (3/8″ in G10 tube for an OD of 9/16″). The drifts will be removable from the rudder stock and the blade will have access holes at the end of the drifts in order to take the blade off. The access pockets will be caped off with small G10 plates and sealed off.

Last week – once all design questions were agreed on – we finally took the old rudder blade of. This rudder was built in such a way that the boat would either had to be lifted up or get onto a pit (either way meaning to get off the trailer), but with the new design and no more use for the old rudder blade we decide to simply cut the blade off. Then the old drifts (welded to the rudder stock) were cleaned off and the stock came out thru the deck. Upon further inspection we decided to have a new gudgeon casted as LUCIE’s current gudgeon was not a perfect fit for the rudder stock. The rudder stock then went to our metal fabrication specialist to set in the seven tapped tubes for the drifts and to replace the pintle at the bottom end of the stock (see pictures). All this work was done over the weekend, very precise and to complete satisfaction.

With the rudder stock back at our shop we first built a template for the new blade, did the lay out for the drifts, scarfed the G10 (1:16 scarf, maybe a bit excessive), shaped the G10, then cut the channels for the G10 tubing that will “house the drifts”, butter-flied the plywood for perfect alignment of the two halfs of the channels. Now the initial shape of the rudder was transferred over to the two inner lifts of plywood and the recess for the G10 trailing blade was routed out. (see pictures)

The initial glue-up of the two inner lifts and the G10 will happen on Friday, following the second glue up of the two outer lifts on Monday (the two outer lifts are already pre-cut). Then we will start shaping the blade and eventually start glassing it over – stay tuned for updates.

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