Beam Bulk/H and Carbon Anchor fitting

After the interior lamination is complete, the next task is the positioning and fitting of the carbon anchor assembly for the folding system, and then beam bulheads on top off them.

Aft beam bulkhead with side panels fitted.

Fwd Beam bulkhead, and post curing the anchor assembly after the additional laminates.

Heavy laminations over the anchor assembly. Very tricky to get the cloth to go down inbetween the slots without leaving air seams, and also to maintain the correct fiber orientation. I ended up splitting each layer into 3 pieces with additional patches over cuts and pleats.

Pre fitting foam for the foam/filler fill between the anchors. Then a few more laminates over this and then thankfully finished. A lot of work involved in fitting these 2 bulkheads, same job has to be done 4 times (either side of eachbulk/h, and made worse by hours of  knee cracking squatting on a sloping hull side.)

But beginning to look much more like a boat at last

Planking cont...

Hull planking for this side now finished. I opted for 8" wide strips ( 6 per 4 x 8 ft sheet of foam) but it does mean a lot of seams to be filled/sanded flush.

I am hoping it will pay off in less filling and fairing being required later on.

I decided to use the dry lay up method this time. Partly because I am single handed on this project, and partly because some of the stitched fabrics are very awkward to deal with. Almost as soon as it is cut from the main  roll it seems intent on distorting and generally destroying itself! And the more you handle it the worse it gets. Trying to position it accurately onto a wet surface makes things even more tricky

Cunning device for positioning cloth with minimal hand contact. Partly successful. ( If you just let the roll drop the cloth bridges the hollows and then need  repositioning, causing more distortion) . The hull shape causes the fibre orientation to change a bit as the cloth goes down toward the gunwhale. I decided the keel area was probably the most important area to have correct.

Ready for resin.( I shall flip the overlaps back as I spread to help to get the resin right the way through the double layers to the foam)

After a long cold winter and having to move location (fortunately within the same building) I have finally made a start on the second hull half.  On the whole the first hull half shape is pretty good, although there are a few uneven patches, where the foam strips did not lie tightly against the batons in the original mold, particularly on the tight corners down by the keel. I have opted to leave the outside of the first half unglassed for now and will do it after joining.

Mold re-assembled ready for planking, (and an indication of the final hull size and shape beam wise).

Fitting the Core-Cell strips. Core-Cell A500 seems to have been discontinued and is now repalced by M80. It seems to be a tougher foam and does not thermoform as easily.

Tight corners down toward the keel. Needs quite a lot of heating and some serious muscle to bend. Difficult not to scorch the foam.

View from the rear.

Hull planking finished

Finally completed the planking and inside laminating of the first hull. Next fit carbon anchor assembly followed by the beam bulkhaeds.

Apologise for poor pictures. My new 12Mg pixel camera produces far worse photos than my ancient 2.6Mg pixel job. No substitute for descent optics.

Beam Bulkhards trial fit. (Camera crooked!) Basic position dictated by the tube through the sprocket sticking up from the frame below (cannot be seen, inside slot), and getting the top edge of the bulkhead horizontal with the hull sides, and in line with the frame.

Trying to get the upper folding slot pin parallel to the hull anchot pins. There is sufficient play in the set up to make mistakes. Bulkheads are heavy and unstable. Keep tipping forward becuase of heavy laminations around pivot pin. Tubes are for sighting through and the wooden struts (one each side of the bulkhead) is to keep bulkhead pivot hole parallel to carbon anchor pin.

Relationship between carbon hull anchors and beam bulkhead. Sighting through tubes looks OK, but it is all quite a tight and stiff fit. Tubes seem very prone to jamming in holes, very frustrating when you have to keep twisting in and out.

Ready for taping in place.

Starting on the Main hull

I finally found a suitable space to rent to construct the hull and floats.  Continuing my back to front build, I have decided to get started on the main hull and leave the floats till later.

Form frames and battens. I made the chipboard form frames some time ago and found that they have all done a little bit of warping/twisting/splaying, and being generally unhelpfull. They are also in 2 parts as the 4'x8' sheets on their own are not tall enough. I have added extra height on some bottoms, and some have extensions on the tops. I have had to spend a lot of time geting them back to upright, flat, sqaure etc.

   If I ever did this again, I think I would avoid using chipboard. It is heavy, brittle and prone to distorting. Any money I saved by using this rather than MDF, has probably been spent on expensive jigsaw blades to cut the stuff!  Beginning of the planking

I have copied Henny's (fram.nl) method of using battens to temporarily hold the foam rather than clamps but with the addition of a small block on the batten to keep the edges butted up tight together.

 I have opted for 9' wide strips, -it does mean a lot of strips to fit, and many seams to be filled, but I found it quicker to thermoform and fit this size rather than struggle with wider pieces. If you give the foam too much heating it tends to expand and distort. I give it just enough to take out the stress and relax enough for the screws to hold it well from behind.

Beam Baking

I am using a similar arrangement as before, but with an additional 60W bulb. 6 in total. Could really have done with 7 to speed up the process and produce some extra heat.

Bearing in mind that there is 60/70Kg of resin and glass in the beams, it is going to be a slow process to heat them up to 50C. There are 25 plus layers of carbon and glass in places, and the heat is going to take a long time to reach everywhere.

I wanted the hot air to be able to circulate all around the beam, hence the side struts to lift up the cardboard.

Cardboard creation. Unfortunately the heat loss from this was too much, and I had to add a lot of blankets and some old rugs to keep the heat in. Coud have done with another bulb, but would exceed my dimmer switch wattage rating..

Initially the heat distribution was rather poor. The hot air was trapped underneath the beam by the sides of the ladder,  and was not getting up to the top surface well (15C difference between top and bottom). I had to add 2 small hot air/cool blower fans (8.99 GBP - Amazon!)  in at each end to circulate the air better.

Finally getting up to temp after about 36 hours! The light bulb method is v slow for a big heavy part like this, but on the other hand you do not have to worry about it all going ballistic and frying the thing while you are away.  I think the maximum heat you can get from this arrangement with no heat losses would probably be about 60C, which would not do any damage.

Postcuring daggerboard and rudder

I thought it would be a good to idea to postcure the daggerboard and rudder parts for extra strength, as they are not going to be exposed to much  heat  when in position. It is not strictly neccessary, as I have not been using slow hardener on these parts. The beams on the otherhand I will have to postcure as I used slow hardener on the multiple layers of carbon UD.
  

 I am reasonably happy with the foil shape. although it has taken more filler/fairing mix than I had hoped for. I used a template CNC cut from the daggerboard DXF file  for the final shaping. Strictly speaking I think I should have postcured before filling and fairing. Hope all the filler does not shrink and crack off!

The heat source. 5 x 60W light bulbs plus dimmer switch. I  have found this to be very controllable.
  

Heat source under the board. The bottom edge of the board did get a bit hotter than the top, but on the whole the heat rising up from below was quite well distributed., about 5C difference between top and bottom. 

Rather crude cardboard oven. But it did the trick OK ( with a bit of additional room heating to cover the heat loss from the cardboard) . It is suprising how long a large piece like this takes to heat up. (and cool down!) You begin to think that you are not giving it enough heat, but in reality most of it it is being absorbed by the board for the first  few hours or so. After that you can begin to actual get the temp up a bit. As the board has a wooden core, I did not want to get it too hot. In the end it had about 24hours at about 45C. (Cure for the resin I am using is 50C for 16 hours.) Hopefully this will be about equivalent.

Oven No:2 for the rudder/sleeve/gudgeons/composite chainplates/bowpole/forestay backet fitting. A smaller volume to heat up, should be a bit quicker hopefully.