But not entrirely off topic. (cross post from http://www.rcgroups.com/forums/showthread.php?t=1616651) This is my first-ever scale boat project. My ultimate goal is to build a ship to participate in Radio Controlled Naval Combat (rcnavalcombat.com), which involves ships much larger than the micro category -- they are usually 1/144 battleships/cruisers at least a metre long. They are scale, but usually not 'fine scale', as they are always getting shot at! I'm starting smaller, to get some experience with the materials and techniques, before I move on to the 'real thing'. I'm building a French Tug, Valereux, in 1/144, about 270mm long. It's the same ship as built (beautifully) here: http://www.rcgroups.com/forums/showthread.php?t=674256 Incidentally, the plans are available for free here: http://www.servicehistorique.sga.defense.gouv.fr/02fonds-collections/banquedocuments/planbato/planbato/listebato/listebato.php -- it's a great collection of French Naval vessels. I'm going to use a variation of this technique: http://www.modelwarshipcombat.com/howto/QuickFiberglassHulls/FiberglassHull.htm to build a fibreglass hull, using a temporary framework of ribs and keel, and CA glue instead of resin. I calculate an approximate 250g displacement for this hull, so it needs to be light to take the motor, battery and RC gear. The Valereux has a concave curve in the deck from bow to stern, and I decided to make the model with the curve. I think that was foolish for a beginner, and it has certainly made the build more difficult. I should either have built the ship flat, or built a flat deck at the lowest level of the real deck and built up the ends with balsa appliques. I first cut a 'building board' out of 3mm plywood (thicker might have been better) and a sub-deck out of the same material. My sub-deck is a 5mm rim around the plan of the deck, with a single 10mm cross piece in the middle. the sub deck is solid for those parts of the boat (the stern mainly) which will be carved out of balsa blovk rather than skinned. The plywood I am using is 'craft ply' -- a single core with a thin veneer on each face, so while it is 3-ply the plys are not of equal thickness. I'm not sure what effects this will have on strength and durability in the water. I screwed the ends of the sub-deck to the building board from underneath, so that I can release it after the hull is finished. I put some packing under the centre of the sub-deck to approximate the curve of the deck. I hope that the strength of the final hull will contain the force of the bent ply. I then cut out the hull profiles from 5mm balsa -- this is easier than cutting ribs, as they are solid -- some people even use corrugated cardboard. I did find that I had difficulty keeping my exacto blade vertical while following a curve in the balsa. The hull sections were glued to the sub-deck with pva wood glue, with pieces of scrap balsa glued between each pair of sections as a keel. Because my curve didn't match the curve of the plans precisely I had to raise some of the sections with shims. I'm now up the point of carving the bow section and starting to skin the hull. I was originally going to use 0.6mm Craft Plywood for the skin, but I found that it was hard to bend it to the radius of the curve of the bilge -- perhaps it would be OK on a slightly larger ship, as it almost worked. I was also trying to glue it with contact cement, which didn't quite have the tackiness to hold it -- perhaps hot glue would be better. I'm going to skin it with 0.8mm balsa instead, which bends much more freely. As the fibreglass is where the strength comes from this will be fine. To be continued...
I've completed the hull. The fibreglass/CA combination was easy to work with, although I ended up with rather rough patches at the edges of pieces of fibreglass, and a skeg which is far too thick. The rough patches need quite a lot of sanding. I'm convinced I can use this method for much larger builds -- this hull used 1/3 to 1/2 an ounce of CA, so it's not too expensive. The hull feels really strong, and weighs only 30 grams (that's 1.05821886 ounces for the metrically challenged . The displacement is 258 grams, so after my estimate of battery, servos and rx weights I'll have about 95 grams (3 ounces) for propshafts, superstructure and miscellany. I was tempted to cut some windows in the hull and make it battleable, but sanity prevailed and I'll wait for my next build, which will be something larger. There are some photos on flickr: http://www.flickr.com/photos/41886002@N05/sets/72157629250789404/with/7020728755/
Looks like a neat little thing, good job on the hull. For a larger ship, I know people have used CA for the fiberglassing, but I'd really suggest trying to find a proper polyesther resin or epoxy resin for fiberglassing. I think you'll find the end result to be much more satisfying and without some of the more brittle properties that CA tends to have. Durability in a combat ship is definately something to consider.
