Monday, July 5, 2010

Building Flat Panels for the Catamaran Hull Bottoms

I am now in the second phase of building my Gypsy catamaran. This phase involves the construction of the hulls. I had chosen to build the hulls out of foam composites . The reason I had chosen Woods designed catamarans is that the hulls can be built from flat panels which is ideal for a "one off" boat. No expensive moulds are required. So, PVC foams had to be purchased from DIAB who has a branch in Thailand. What I cannot comprehend is that while they sell the foams in Thailand, they do not keep stock of the BONDING PASTE that is required to bond the PVC foams to the glass. After serious consideration I decided to get the bonding paste from DIAB in Australia instead of using substitute as the hull is a very important part of the boat and I do not want any delaminatons later on. However, I am still sore with this "Poor business practice" which resulted in me spending a lot of hard earned money for transporting the 3 pails of Divilette 600 bonding paste . Total weight is 60 kilos and it is classified as dangerous goods !

The mould for the flat panels are 16 mm melamine chipboards. These boards are 8 ft by 5 ft in size and I am building half a panel at a time. Catamaran length is 28 ft so 2 pieces of melamine board joined together is enough for half a hull length.

The dimensions of the bottom panels as per the plan are marked onto the melamine board using a water based marker pen.

The two small pieces of 3 mm melamine wood strips are added to make the flanges. This makes it easier to join up with other panels later on.The bottom panels of the catamaran does not call for any PVC foam or gelcoat. The layers are 300 gm CSM followed by 3 more layers of 600/225 biaxial mat. These materials are bonded together using polyester resin. I had purchased BQTN resins which does not have a layer of wax and is la ow Low Styrene laminating resin.

It takes me about 3 hours of work to get one panel ready. The panel is then left overnight for it to cure (solidify).

The manufactured panels are easily separated from the mould. I had finished building all the panels for the bottom of the Gypsy. It is a good experience and I will move on to building the panels for the hull which would be more interesting as this is where the PVC foam will be used.


  1. Wah, well and truly into phase 2 now. Well done

  2. Captain,

    While building your catamaran, still have time to take good care of your durian farm! A lot of energy!

    By the way, your durians were good and it saved me a dinner. I particularly like the one with yellow pulp. The seeds were small and the pulp portion was big, and it was filling! Thanks!

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