Posted by Richard Jenkins on May 31, 2000 at 11:11:19:
In Reply to: FLOATING 1:570 MODEL TITANIC posted by WILL on May 30, 2000 at 16:38:12:
: COULD ANY ONE TELL ME HOW I CAN GET MY MODEL TITANIC TO FLOAT IN WATER.
You have to assemble the hull without putting the upper decks on. Use a couple of pieces of scrap styrene to close up the slots in the bottom where the hull is supposed to sit on the display stand. Test the hull for leaks by filling it with water and holding it up to see where the water is coming out. Seal any leaks with modelling putty. Once it's watertight you'll need to add some ballast to get it to float at its proper waterline. Fishing sinkers work well for this. Add them gradually while the model is floating, until the model has reached the desired waterline, and make sure it's sitting upright in the water. Keep in mind the weight of the upper decks that have yet to be added - at this point you have probably added enough ballast that the weight of the upper decks won't upset the model's stability, but they will cause it to sit a little lower in the water, so take this into account when you're ballasting. When you're satisfied with the way it floats, secure the weights with CA or epoxy. (Do not try to use plastic cement for this, it will distort the hull. Don't ask me how I know!)
If you want to add a motor I'd suggest just powering the center propeller for simplicity's sake. Add the motor and running gear after you make sure the hull is watertight but before you add the ballast. A 1.5 volt motor should do the job, along with either a "C" or "AA" battery. Use 1/16" (or similar) steel rod for the propeller shaft, and brass tube that just fits over the rod for the shaft bearing. The tube should be about 1.5" long. Drill a hole through the hull where the propeller is supposed to attach, and insert the tube. You'll have to do this from inside the hull because the stern post will be in the way outside. Don't glue it yet! Coat one end the steel propeller shaft rod with Vaseline (to lubricate it and prevent water from entering the hull around the shaft) and pass it through the shaft bearing. Use a 1/2 to 3/4 inch length of rubber hose, just big enough to fit snugly over ends of the propeller shaft and motor shaft, to connect the other end of the propeller shaft to the motor. Fix the motor into the hull (there are lots of different ways of doing this depending what kind of motor you use), and try to keep the motor shaft and propeller shaft in a straight line. Once the motor is properly mounted, glue the shaft bearing into the hull with CA or epoxy, and float the hull to check for leaks. If water gets in around the shaft bearing, seal it with modelling putty or epoxy. If water gets in through the shaft bearing, add more Vaseline around the inside end of the bearing. Clean any Vaseline off the outside end of the propeller shaft and glue the propeller in place with a drop of CA. Be very careful not to let any of the glue get into the shaft bearing. Add the battery and then ballast the hull. If you do plan to motorize your model, you'll also have to make some kind of arrangement for battery access when you add the upper decks.
A much easier method for motorizing might just be to add one of those motor pods that clips on to the bottom of a toy boat.
If you're really ambitious you could probably add radio control as well! I doubt the 1/570 hull would be big enough to float a hobby grade R/C system, but perhaps a system from one of those single function (forward/turns-in-reverse) R/C toy cars could be adapted to steer your model.