Along with Okoume hull and deck test panels, I made a set of Meranti panels to evaluate using this option to build our Class Globe 5.80 #71. Specifically I was interested in the cost reductions associated with using less than half the resin and fibreglass compared to the Okoume option, and if there was a weight penalty by using the heavier Meranti plywood. For boats built with a 9mm plywood species other than Okoume, there is a laminate specification of 450g/m2 for the hull and 200g/m2 for the deck. I used the same criteria for selecting a laminate layup for the Meranti option as I did for the Okoume one. The fibres had to be easily sourced, have the possibility of adding a structural component, and contribute something positive towards to the finishing process. After considering the options available to me at writing, I have settled on an EC290 and an EC200 for a total laminate weight of 490g/m2. Essentially, this is 2 layers of what is often called boat cloth, a woven fabric used more for its ability to hold an even and consistent film of resin than for its structural contribution. While I have not managed to meet all three of my selection criteria, I have found a good balance between ease of use, weight and cost. The boat cloth used comes in a 1m wide roll, not the standard 1.27m wide rolls supplied when using heavier stitched fabrics. This makes handling the usually malleable and quite delicate boat cloths a bit easier. The combined weight of these fabrics exceeds the minimum laminate weight requirement by 40g/m2. This will add about 1kg to the structure. Not a big deal! The use of a quality peel ply will result in a even and consistent textured surface that will require little in the way of preparation for the filling and fairing stage. The numbers for the Meranti hull and deck panels are as follows: Hull plywood weight m2 - 4.952 kg Hull fabric weight m2 - 490 grams Hull resin weight m2 - 662 grams Hull total resin weight - 13.41 kg Deck plywood weight m2 - 5.008 kg Deck fabric weight m2 - 200 grams Deck resin weight m2 - 352 grams Deck total resin weight - 5.08 kg When it comes to laminating the hull and deck using the above fibreglass layups, make sure you have at least 24kgs of West System brand resin and hardener available to complete these jobs. You can read about the Okoume test panels here.
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