Good eyes. I had not noticed that myself. It might not be as important to bend the shaft slightly in the rudder on a destroyer. But one wouldn't want to find out the hard way in the middle of a battle. Mikey
The rudder shaft is straight, my cruiser is set up that way and I didn't have any problems. But I see your point and I'll probably put a bend in subsequent ships so I don't have to worry about the glue joint failing.
I completed some tests on different casting materials. The 6 test turrets are, from left to right, regular water putty, Alumilite, water putty coated with tool dip, silicone, West epoxy, and water putty with micro balloons. Results: Top left and middle are the coated water putty. It survived the hits pretty well, much better than the uncoated. Once there were multiple hits close together or close to the edge, the casting did fracture. The Alumilite in the top right corner showed a couple of dents but was basically unharmed. The plain water putty in the bottom left survived some pretty good hits, but split when a several hit in the same place. The epoxy in the bottom middle was completely unmarked on the outside, but you can see an internal fracture starting in the middle of the door. The bottom right is the water putty mixed with micro balloons - the holes are pretty deep, but as long as the hit was not near the edge it survived. I don't have a picture of the silicone, but as you can expect, the BB just bounced off. So in order of preference: 1. Alumilite - 8.6 grams turret weight, cost $0.328/turret, expensive but light weight and durable. 2. Coated water putty - 11.5 grams, $0.062/turret, cheap, slightly heavy and reasonably durable 3. Water putty - 11.3 grams, $0.062/turret, cheap, slightly heavy but a little brittle 4. Epoxy - 9.3 grams, $0.443/turret, expensive and possibly too brittle for long term durability 5. Water putty with micro balloons - 6.4 grams, $0.035/turret, light but soft -- use only if weight is paramount 6. Silicone - 7.8 grams, $0.018/turret, difficult to get a good casting, not paintable, watch the ricochet
I'm glad the Alumilite did well, I can get that easily (easier than I was ordering Smooth-On polyurethane, which is not really hard to do).
There is a number of hobby shops that carry some of the Alumilite line, or you can order from them directly. I got mine from a hobby shop in San Diego that I visited when I was on a business trip out there. Just look at their dealer list to see if one is near you.
Have you considered combining materials? I imagine a 1/8th thick urethane turret with a water putty/microballoon core.
Interesting that you suggested that. One of the original materials I was going to test is the self-leveling polyurethane that I use for water channeling. I waited for it to dry for two days and it was still liquid inside, plus it stuck to the mold. I finally got it out of the mold (lost the mold) and I decided to cut off the bottom and let the liquid drain out. Once the inside cured I started playing around with it again. Although very flexible, it does retain its shape and it shows the mold details pretty well. The sides are about 1/8" thick and all I would need to do is add a plywood bottom to mount it. Right now I have put a coat of paint on it to see if the paint will stick. Hopefully it will, but if it doesn't the natural color should be pretty close to the ship color. I also have a mold release that I think will work, so that will solve the sticking problem.
one thing to think about with the cement leveling compound would be to use it like folks use paint/gelcoat on wing mold. put your release agent on, paint it on the mold reasonably thin, let it cure, then fill the mold the rest of the way with your cheap foam.
That's what I had in mind. Instead of cement levelling compound however, I was thinking of sikaflex rapid cure in grey.
Well, I took a couple hours off tonight from molding and finished up the basic superstructure for the Gridley. I still need to put together some torpedo tubes and a spotlight closer to scale. I am very pleased with how the director came out.
Looks good - one question - the stack seems overly tall? It looks like its taller than the director, but every picture I've seen it looks like the stack is the same height or a little lower.
Gorgeous, but I agree with Nick, the stack does seem too tall. The hull also looks a bit stubby so it may be a bit of photo distortion.
Nick is right, the stack is too tall. It's too tall by at least the height of the stack topper, which I added after I made the foam pattern for the base. Once I make the mounting pedestal for the director and glue the forward superstructure together, I'll check the height and shorten it to a better height.
