Archive for September 2015
Today was the first chance I had to see the keel now that the foundry has added the last 650 kg of lead to the fin section. I calculated out the amount to go in each of the three chambers and the foundry batched each load separately. I was a little out with the estimates and the last few kg were added to the central chamber. The benefit of large pour is that each lead section is structurally sound while the downside was a slight bulging of the walls between the vertical pipe stiffeners due to the heat. With a little filling and fairing we will have a good finish.
The yellow lines on the side of the fin show the level of the lead. From the lines down to the base it is 1650 kg of solid lead.
The Didi 40 Cr fabricated steel lead filled keel. The two yellow lines on the side show the level of the lead so the centre of gravity of the keel is nice and low.
In preparation for installing the settee backs that form the box structure supporting the chainplates I am painting inside the shelves and the back of the plywood front. These are small shelves with just a 150 mm wide opening so to paint them after assembly would be quite difficult. I have used three coats of Interprotect two pack epoxy primer for the inside of the shelves. On the settee backs I masked off the area which will be glued to the frames and shelf front cleats and you can see from the photo of the inside face of the settee backs that there is a large gluing surface area.
Didi 40 Cr settee shelves part painted and with wiring and plumbing holes cut.
The settee seats form the water tanks on both sides of the Didi 40 Cr so I have purchased the fill hose and cut the holes in the tank top for the fill and overflow lines. These are positioned in the corner of the shelves out of site so I will install the hoses onto the tanks before epoxying the seat back in place.
The inside of the settee backs has already been painted with three coats of Interprotect two pack epoxy primer. I masked off the areas that will be glued to the shelves and frames.
On Monday the last 650 kg of lead was poured into the bottom half of the fabricated steel fin section so the keel should now weigh the full 2000 kg. Also on Monday the contractors commenced constructing an awning over the hull. The awning will shade the middle seven metres of the hull to give me some protection while completing the deck and fit out. The posts for the awning have been purpose designed to support the load of the hull while we turn it over in slings. This is still a way off yet as the concrete footings have just been poured. In the meantime I have quarter berth shelves to fit and lots of painting to complete outside and inside.
The last race of the RANSA Winter Series was almost identical to the previous week with perhaps a little more breeze. The six yachts that places from third to eighth finished within a minute of each other and unfortunately we were the eighth.
The first leg was a reach to the heads followed by a reach back to Steel Point. After a very good start the faster yachts progressively sailed over the top or by the lee but we managed to hold out Rainbow at the turn. On the work back to Steel Point we sailed a higher course and in the fresh conditions risked going close into the point. With that one move we overtook Enigma and looked to have prospects for a good handicap place. Unfortunately I focused too much on staying in front of Rainbow and did not appreciate what a large knock we, Rainbow and Enigma took over on the Shark Island side of the course. Had we tacked on the first header into Rose Bay we might have finished much higher up the order.
We had a tight contest with Rainbow all the way around Shark Island and managed to time our tack to the turning mark to perfection to open up a small lead. We needed all of this lead to manage the broad reach to the finish line in dying conditions. Meanwhile Enigma who had been tucked away well behind made up enough ground on the broad reach much as she did last week to pip us on handicap.
The light breeze on the run to the finish did not help our handicap prospects as the faster yachts were already home in fresher conditions.
Despite the modest result we enjoyed the afternoon and celebrated the end of the season with a glass of bubbly.
Not much to show for a week of working on the project because it is all fiddly work fitting shelves and filleting and glassing them to the hull to make a strong box structure to support the chainplates. I have now glassed all the shelves in the photo to the hull on both sides of the boat. I need to fit timber cleats around the lip of each shelve to glue the settee backs in place. The settee backs are already cut to size and fitted but I intend to paint the inside of these storage spaces and the backsides of the settee plywood before gluing them in for good.
Plywood shelves to be glassed to the hull to form a box structure to support the chainplates
One other task completed was the “P” bracket support inside the hull. The inboard end of the bronze bracket is now encased in two substantial plywood blocks which are bolted together through a frame.
The title is a bit of an exaggeration as we did have to tack around a couple of marks as well but out on the course there was just one tack to make the Rose Bay mark and one tack around Shark Island. Apart from that it was a beam reach up and a single board back to Steel Point.
Tracks from our two tack race today
We generally do better relative to the fleet with a square run and a work but today we were powered up close to the top of the wind range for the carbon tri radial genoa and managed a fifth place on handicap.
I have not yet seen the times for today’s race but from the series results shown on RANSA’s web site our position was fifth just behind Enigma, Izzi, Trim and Mercedes IV who was first.
This result moves us up one place in the series to fifth overall just ahead of Rainbow and looking at the scores a fifth is the best we can do with one race to go.
What more can we ask for but a beautiful spring day on the water and finishing in the top half of the fleet.
Thursday last week was devoted to supervising the assembly of the fin onto the bulb which is now filled with a tonne of lead. The laser level came in handy for getting the vertical alignment right and in six hours the fin was welded to the base ready for final structural welding around the perimeter. It looks large and as my daughter says “serious metal.”
Bulb and fin of our Didi 40 Cr keel joined ready for final structural welding.
The upper and lower rudder bearings are glassed to the hull so I fitted the first half of the rudder to the stock on the hull today. The size of the rudder came up in two separate discussions over the weekend so after the fit today I was able to stand back and get a good idea of the size. It looks pretty big to me. What to you think?
After a successful trial fit and final adjustment of the top of the rudder to the hull shape I bonded the two halves to the stock with a lot of glue.
Getting a feel for the rudder size on our Didi 4 Cr
The rudder half clamped to the rudder stock of our Didi 40 Cr for final adjustment.
With the two halves of the rudder of our Didi 40 Cr glued together the total weight is too heavy for me to handle so the next time the rudder stock will go into the hull will be just prior to launch.
In the week since my last post it would seem that not a lot has happened but a lot of fiddly jobs are going on under the hull. The rudder post bottom bearing is now well glassed into the hull and four plywood gussets have been glassed around it to make it strong enough for construction activity. After the hull is turned I will add five more layers of fibreglass to the plywood gussets which should make it very durable.
The stern tube through which the propeller shaft exits the boat is now glassed in and the propeller shaft is temporarily installed to ensure the everything stays straight while the glue sets. Similarly the P bracket which houses the bearing just in front of the propeller is glassed in place. I was not confident to do these tasks until Kevin came around for the afternoon and we could run a string line from the front of the engine centreline to the rear of the P bracked centreline to ensure all was aligned correctly.
While waiting for the glue on these tasks to set I have been back under the boat putting epoxy fillets between the frames and the hull skin and between the structural shelves and the hull skin. These frames and shelves can now be glassed to the hull for a very strong structure.
Not many of these tasks are worthy of a picture but I have been doing a bit more torture boarding and getting the finish on the hull closer to my target.
Using the sunlight to check how the hull fairing is progressing on our Didi 40 Cr.
At 9 am at home it was cold and overcast but by the time we hit the start line the sun was out warming the day. Motoring through Humbug on the way to the start line we spotted our seal enjoying the high tide in the harbour and this time captured him on camera.
A seal in Humbug enjoying the Spring weather.
The north east breeze kicked in as we motored to the line ensuring a good windward work to the top mark. We set the carbon tri radial genoa as we seem to be able to carry her into higher wind strengths successfully and enjoyed a work where we crossed tacks with our competitors, Izzi, Fidelis and Viva on several occasions. The strong outgoing tide always makes for complimentary tracks on the chartplotter but we did try to take advantage of the lifts and knocks and seemed to to quite well compared to our usual position.
Complimentary tracks with an outgoing tide
The run back to Steel Point was very square and the rhumb line kept us out in the tide. Perhaps we should have jybed away for a clean line of breeze away from Ichi Bahn, Viva and Izzi and less tide but we hung on on Starboard gybe until the point at which time Izzi crossed behind and went above. Up front in Rose Bay the fleet was tight reaching to the mark while we were still running square in the same direction. Izzi to windward got the strengthening header jumped ahead. Around Rose Bay we were reaching to Point Piper with the fleet not far in front and feeling pretty happy with our position. Agrovation had a nice new set of sail on board and had been well ahead but here she was retiring from the race after an unfortunate collision. Rainbow who had been late off the line was still well behind and we had Enigma and Viva covered. It was fortunate that we were so well up at this stage because the breeze began to fade so we were coming home in lighter breeze than the front markers. Viva was very notable punished by the dying breeze and Enigma and Rainbow not helped at all.
Across the line we were happy with the result expecting to see Mercedes do well as they sailed well in the fresh breeze off the start line. On handicap we tied for third with Larrikin with Mercedes first and Amante second so it was a great first race of Spring.