SKEG REPAIR – SHAFT, PROPELLER & TILLER INSTALLATION – POLISHING GELCOAT – MAIN SAIL TRIAL
We had a very bad surprise when we pulled out the machine screws holding on the heel plate. While inspecting thoroughly those voids, we realised that the previous owner had fill up the old machine holes with quite a lot of filler. This filler was cleaned away with the help of the Dremmel. And because this is a very critical area, we had no other choice than to consider a strong rebuild in order to obtain new threads in the resin.
The very deep voids were all filled with resin, silica and milled glass. This combination of materials is ideal for such a repairs.
The main difficulty was to make sure the resin was thick enough to stay in the holes. To get around this problem, we mixed the epoxy with silica until we obtained the consistency of peanut butter.
From the outside, the bottom of the skeg was also re-enforced with a few layers of woven roving giving therefore more structural strength. The whole area was finally covered with a layer of Peel Ply. As we mentioned before this material protects the surface and allows the resin to cure in the best conditions. It also provides a nice finish when it is peeled away.
Once the repair was solid, we had to open the new holes. A tap and die tool was used to create new threads into the skeg.
We used a spiral point plug tap with a tap handle. Firstly, the four holes were drilled to a smaller size than the tap’s main diameter.
The old and the new heel plates. The new heel plate was ordered from J. Rogers Limited. Unfortunatelly the bronze ring inside the plate was slightly larger than the rudder shaft. That would create vibrations at the helm, something rather annoying. We managed to solve the problem by manufacturing a new bronze ring according to the rudder shaft. The difference between the shaft thickness and the bronze ring had to be what we call, an “interference fitting”. Luckily enough, our friend Fotis has a metal lathe and did the ring for us. He also had in stock a raw piece of phosphore bronze which was what we needed for the job.
After solving all the problems concerning the skeg, we fitted on the new heel plate.A layer of marine sealant was applied in between the plate and the skeg. This sealant will insure watertightness and hopefully, will keep the machine screws dry. On the rudder shaft itself, we applied a generous quantity of marine grease.
The heel plate was strongly screwed in place and the movements of the rudder were finally nice and smooth.
Under the heel plate, a GRP skeg cap had to be attached. Duck tape was used to hold it in place while the first filler was curing. As J.Rogers recommends, we firstly used polyester filler to bond the cap to the skeg. This is much easier to use than epoxy, mainly because it dries very quickly.
Later on, the repair was covered with a nice epoxy lightweight filler. As we mainly work with West System, we used the Low Density filler 407. This powder additive permits to obtain a very smooth surface and has the advantage to be easy to sand.
Lastly, a few coats of epoxy paint were applied to cover and protect the repair.
Polishing the areas around the windows revealed the excellent quality of the 43 year old gel coat.
We used the wet sanding method because it allows to obtain a smoother surface compare to the dry sanding. We started with 1200 and continue with 1500. Then we applied the One step 3M Polishing compound with the Fein Multimaster tool.
The Fein Multimaster tool is obviously not a proper polishing machine, but with the appropriate polishing sponge, it did the job very well.
When polishing the gel coat, it is always better to work step by step. Masking tape is used to indicate the area which has to be polished. It is always better to work this way especially when it is cloudy. The use of polarising sunglasses is also of a great help when it starts to get very shiny.
On this picture, the blue masking tape has been removed and the difference is now noticeable.
An important remark considering the gel coat. During our 23 months stay in the boat yard, we noticed that a lot of owners are asking professionals to repaint their boat. To be honest, we also thought about it. But after polishing on deck around the windows, we realised that the quality of the Contessa’s gel coat is excellent. Compare to most of the boats which are around us in the boatyard, it is amazing how good our topsides looks. Contessa’s seems to have been produced with a rare quality of gel coat which can easily be restored in few afternoons.
The main sheet with two brand new Rutgerson poulie blocks.
At last, the new Quantum main sail was hoisted !
The instrument console had to be slightly modified to fit the new instruments. The three old holes were closed with epoxy backing plates and filled up with low density filler.
And the console was repainted.
Finally, two new i50 Raymarine instruments were installed and connected.
At the moment we only have a depth and a log instrument, and we think those are enough.