Week 11 - Centreboardcase

After weeks of working on the shell (the hull) we now started fitting the interior elements of the boat. With other words... many weeks of amazing woodworking, a good motivation push!

The first part needed was the case for the centreboard.
Glóey has a quite strong centreboard (1 3/8" or 34mm) and I decided to build the CB-case out of 2 sides of 1" marine plywood which is very formstable and flat.

As visible on the photo to the left we applied formica sheets inside on the inner sides. It's function is to both provide a good glidingsurface for the pivoting centreboard as well as to protect the wood from abrasion.
The two sides are glued to an inner frameconstruction. Referring to the index on the photo left A is the inner part in the cabin which also will serve as a table meaning that 2 foldable tableleaves will be fitted to the frame and the void inbetween can be used for  things like cutlery or whiskey glasses :-) ... however!
B is the little pulley-block-case from where the sailer can turn up the centreboard by pulling on a rope.

C shows a kind of console on which the mainsheet svivel with a jammer gonna be fastened (see last photo).

Contemporary wooden boatbuilding is a mixture of modern gluetechnique and traditional joinery and the CB-case shows that fact very clearly.
Even if Epoxy is an absolutely strong adhesive many joints will still be stronger if they also are done traditionally. Here a mortise/tenon joint is used to reinforce the console of the mainsheetsvivel and at the other end the inner frame forms a traditional dovetailjoint.

And here it is... the whole centreboardcase build up on two strong logs which will meet the hog when fitting it into the boat. Indeed the ballastkeel will be fastened to those logs with siliconbronze bolts.

Well one little element is still missing... I'm talking about the 2 curved endcaps on either aft side of the case. They were build by laminating mahogany-veneers to a former. The following picture shows that step. To end up with a best possible result of the laminate we glued very prudently and used G-clamps in a very tight spacing.

Another important factor was to achive a very much similar curve of the former as the one on the CB-caseside. We've choosen a routerbit with an aligning-bearing to manage that...

... and well, it fitted nicely!

Week 10 - Inside sheating / Beamshelf

Taking off the hull from the moldes and turning it to it's upright position was an exiting moment.
Now the plan was to get the insidesurface ready for sheating with biaxial glasscloth and epoxy in 2 days.
First step was to clean the surface from all glue excess, a surprisingly easy job that worked really well with a chisel. Then the whole stripplankingsurface got scuffed off. Similar to the scuffing off on the outside of the hull we move the plane in diagonal strokes over the strips and take the highspots off.

The plane used is an old wooden bollowplane followed by a flat spokeshave.
After that we sanded the whole surface with a DA-sander which works really effectiv and well.

After a prudent go with the vacuumer the hull was smooth and more or less dustfree.

Now it was time to cut the fiberglasscloth in overlapping panels. Again here the same deal as on the outside so 2 layers of 300 gr/m2 biaxial each.

Sheating the inside of the hull is definitely a little bit more tricky than the outside because of the narrow workspace and the fact that the glass was divided in 2 sides by the hog.

We were 2 guys working inside the hull balancing on the hog which was protected from the resin by a plastictape. Principially ok but during the laminationwork   epoxy resin dropped to the surface of the hog and thisone got more and more slippery.
Another 4 guys helped from outside the hull.

On the photo above you can see details of the biaxial cloth both in loose and laminated condition. 

After trimming the sheer to it's lofted line we finally could get a good imagination of Glóey's future deck and transom.

This was the right moment to level the boat. We used a selflevelling laser on a tripod to position the boat correctly. I was very happy that we did mark the DWL waterline on the hull as long as thisone was upside down on the moldes. So it was relatively easy to align to this referenceline in the upright position. While the boat was layed on 2 heavy wooden blocks and 2 strong posts clamped to the hull held it in the level position we built a strong cradle.

On the photo above the laserlines are visible both on the centre of the stem as well as along the waterline.

We kept the pads of the cradle just below the waterline to make it easier to paint the hull later. So we will be able to first paint above the waterline and then apply the antifouling after.

Time to glue the beamshelf consisting of 2 pieces of douglas fyr 3" x 1 1/4". Because of the quite strong twist there was a lot of tension on it when fitting it to the sheer and therefore we had to do it in 2 steps. And now we have a really strong sheer which is ready to get the whole deckframing inside...

Week 9 - Sanding / Hullturning

Actually the sanding process to get a nice smooth hullsurface allready started parallel to the work on the keel. It is not the nicest job to be honest but we managed it in 3 days and were really happy with the result.
To protect the rest of the workshopzone we worked in a tent of polythene and to protect ourselfs we did use the dustfiltermasks.
After having tried out both the orbitalsandermachines as well as the sandpaperboards the last one defintely seemed to be the better choice to treat the hullsurface.

The filler we applied every night on all low and flatspots was quite easy to get off and with the help of a workingtorch we tried to locate the last unfair spots the evening before going to the next step > painting the hull with EPU epoxyprimer.
We used 2 coats of EPU and before that coated the wooden parts of the keel with epoxy.

The next target then was to wet and dry sand the whole hull outside until having reached a surface quality comparable to a satinmatt pingpongball.
But before doing this we filled all those very small pinholes and scratches with a polyester based filler called P38.

So we got all this fillingspots as visible on the photo  to the left and thereafter the wetsanding-party could start.

Well... on tuesday 4th of september after lunchtime we were ready to turn the hull.
The whole class helped us to lift it off the moldes... turn it 180 degrees and place it softly down the floor in it's upright position... 

Wow, she's beautiful...

a moving moment and a milestone during the buildingprocess...
Thank's everyone who gave us a hand!

Week 7/8 - Keel, Stem, Ballastkeelplug

This post of my diary comes a little late just because of some very busy weeks and some days off to visit my family in Switzerland... but nevertheless here are a few pictures and comments about building the outer backbonestructure, the keel and the stem.
 As visible on the photo to the right we laminated relatively heavy boards of sapele on to the outside of the hog which is slightly bend towards the bow. These boards are 1" (25.4mm) thick and can hardly been called veneers... however they build a quite substancial keel with a gap in the centreboardarea at midships where the lead ballastkeel later will be fitted.

On the bowside the outer stem had to be fitted with a glued scarfjoint. While planing the scarfsurface on the stem all the kaya mahogani veneers appear in a regular and quite decorativ pattern. Ideally this surface should be deadflat to get very high quality joint.

And finally as seen on the following picture the stem is glued on the apron (innerstem).

After the laminationwork the whole keel and stem had to get his final shape.

For an effective way of working we used the electroplaner first and then did all finetuning by handtools as usual.

At both ends of the ballastkeelgap we chiseled a tenon to give the leadkeel which will come with the fitting mortise a better fixation.

The stem gets the traditional cutwatershape as shown on the photo. So the frontsurface which will "cut" the water will be reduced to only 1" and at the end when skrewing on all fittings we will put a brass keelband on the stem to protect it from potential dammage.

Finally I want to write about the ballastkeel.
Well, as mentioned before Glóey will have a cast ballastkeel in lead. It is a longkeel with a slot for the centreboard, 2.3 m long and 1000 Lb (455 kg) in weight. The ballastkeel will be fitted with 9 3/8 siliconbronze bolts to the backbonestructure.

After having received a quote from the UK foundry Irons Brothers in Cornwall for about 4900.- £ to fashion the leadkeel after drawings I had to think about alternatives to bring the costs down.
First I was thinking of casting the lead keel by myself but after some internal discussions and considering the allready very tight timeschedule I decided to just build the plug or pattern (male mould) with my team and only buy in the leadcasting. Consequently the costs dropped about 40%.
Ok, so here is the plug we've made in solid MDF and which has got covered with some filler and EPU paint for a harder surface and better release out of the sandform.