How to Build Perfect Water Channeling (without using toothpaste!)
After building so many ships, I can honestly say I've tried most any way of constructing water channeling. What is this remarkable thing called a water channel? Simply put, it's what you do in the bottom of your ship, to help direct water to the bilge pump, minimizing the amount of water in your ship after you have "pumped out". Let's discuss 2 different approaches to water channeling... scratch built, and a fiberglass hull.
When scratch building, the builder should consider the position of the water channeling as a part of the hull building process. I prefer to scratch build with the hull upside-down, so that the subdeck is on a relatively flat surface. In this position, the water channel would be at the top of the ship. Using balsa block, install channeling inbetween each rib, leaving a 1.5" channel in the center of the ship hull. Using squared-off balsa block is easy... don't worry about the hull contour. Simply install first, then use a razor saw to cut off the large pieces of balsa, and then use an orbital sander to sand to the contour of the hull. After sanding the water channeling, some builders like to cover the hull bottom with fiberglass. I prefer to use 1/32" aircraft plywood.
When you have a fiberglass hull, everything is easier EXCEPT the water channeling. Trust me on this, I've tried everything from plywood, to foam, to silicone, and the very best water channeling is made using balsa block. Because you have a fiberglass hull, you must shape the contour of the balsa to closely fit the hull shape, and tack into place using CA. Once the basic channeling is in, I like to cover with balsa sheet (about 1/16" sheet). After sanding, I coat the water channeling with epoxy, taking care to completely fill the gaps between the balsa and the hull, and popping any air bubbles before they dry. A lot of other techniques are available, but balsa block, coated with epoxy, is my favorite!
A Reliable and Centered Swampworks Pump
A terrible thing happened today. I was (thankfully) testing my new Swampworks bilge pump, about a week before my first battle, and all of a sudden I heard the pitch change. I realized quickly that the set screw had worked loose from the impeller, and the motor was no longer spinning the impeller. That can be deadly on the water, so I proceeded to take a close look at my new pump.
The first thing I noticed is that my small cruiser motor shaft did not have a tight fit with the impeller. In fact, it wobbled quite badly, and made the impeller go off-center when the set screw was tightened. In order to ensure a centered, and reliable pump, I had to rework the way that the impeller is mounted to the motor shaft.
First, I found a piece of brass tubing exactly the right ID to fit tightly over my motor shaft. Then, I drilled out the impeller center so that the brass tube would fit tightly inside. Finally, I cut out a small area in the side of the tubing for the set screw to penetrate. I carefully centerpunched the tubing, drilled a small hole where the set screw would penetrate, then filed the hole into a large enough opening. Last, I pressed the tubing into the impeller, and filed off the ends to fit the impeller exactly. With this improvement, my impeller is centered. In order to attach the impeller securely, I filed off a flat area on the motor shaft, then after installing the assembly I used Locktite on the set screw.
With a brass tube in place in the center of the impeller, I then carved out the set screw area. Using a longer screw with the same threads, I was able to insert a brass nut into the set screw, and epoxy in place. The nut helps to keep the set screw tightly against the motor shaft. I took my pump, with these modifications, to my first battle. The pump worked very well! Swampy was very nice and gave me a spare impeller, and then modified his impeller design to incorporate my suggestion. So, if you bought a pump from Swampworks recently, you'll notice the nice new brass insert!
Turning Is Better With Shorter Props
In order to have good turning on my cruiser, I was told many times to get my propeller as close to the rudder as possible. Looking at my new props, I noticed that I could get a good quarter-to-half an inch closer to my rudder if I eliminated the taperred tail cone on the back of the prop body. Robert Rucker provided this tip, and it worked well when I made my props shorter!
First, get a short piece of brass rod that your prop fits onto. File a flat spot, and tighten the set screw of your prop, to get a good tight fit to the short rod. Insert the other side of the rod into your motor-tool (or drill press). Clamp a hack-saw and a metal file into a vice, and turn the prop against them to cut and round-off the end of the prop. Be careful not to grind up the blades. You want to be careful to avoid heat build-up, as the solder can melt, and the blades fall out.
How to Make and Install Stuffing Tubes
Stuffing tubes are used to align the prop shaft, and to prevent water from entering through the shaft area. After some real trial-and-error, I think I have discovered the best way to make and install stuffing tubes.
In order to make stuffing tubes, go to your local K&S Brass supplier (most hobby shops) and get 1/8" piano wire (steel) rod for the shafts, and then the next 3 sizes of brass tubing that fits over this. You want to use the first two sizes larger as bushings that the shaft will be aligned with, and the 3rd size larger tubing for the actual stuffing tube. You will not need any grease fittings, so if you have a kit, throw these fittings away. The best grease for a cruiser or destroyer stuffing tube is sewing machine oil or WD40, which can be easily applied to the prop shaft. The best grease for a battleship is vasoline (or lithium grease for you die-hard marine buffs), which can easily be applied inside one or both of the stuffing tube ends. To assemble the stuffing tube, cut the two smaller diameter tubes into a piece 1 to 2 inches long, and deburr with a sharp hobby knife. IMPORTANT - SAND THESE BRASS INSERTS THOROUGHLY, or they will easily break. Glue the smaller tube inside the larger tube using CA glue. You want the exposed ends to be flush, to serve as a thrust bearing surface. With your propeller and coupling on the shaft, measure how long the stuffing tube should be, allow at least 1/16 inch clearance, and cut the largest brass tube to length and deburr. Finally, use CA glue to set the smaller tubes in each end, again making the ends flush.
When aligning the stuffing tubes in the boat, insert the prop shaft, and ensure good alignment with the motors and with the props. This means you will want the motor mount positioned so that the stuffing tube will be nearly horizontal. The props should be very close to the rudder, to the ship hull, and to each other. With a fiberglass hull, I like to cut a large hole, set the stuffing tubes in place, tack with CA glue, cover the outside with electrical tape, and fill in with slow-curing epoxy resin.
Finally, to finish off the installation, I like to solder a brass support to the stuffing tube, and then epoxy the brass support into the ship hull. It makes for a very durable and rugid prop shaft installation!
Protecting Your Gun Barrels
After spending quite a bit of money on a new CO2 powered BB gun system for my cruiser, I realized the importance of protecting the gun system from damage. This protection includes a secure mounting system, protection inside the hull, and protection above the decking. Assuming everyone knows how to install inner-hull protection (using inexpensive plastic wrap from Radio Shack), I will explain a couple of systems for protecting your guns above the deck.
The first method, is covering the barrel with a brass sleeve. In order to protect the gun barrel, you will need two pieces of brass tubing, the first to fit exactly over the gun barrel, and the second to exactly fit over the first. This "triple layer" of protection is used by cutting about quarter inch long pieces to slide over each end of the barrel, and then using the largest size tubing the full length of the barrel, thus creating an air pocket between the outer tubing and the actual gun barrel. Use fine sandpaper to clean the tubing, and use CA glue (super glue) to attach the brass. Finally, use a center punch where the safety pin hole is, and punch only one side, exactly where the gun barrel pin hole is. Use a sixteenth inch drill bit to drill out the hole from one side, then carefully insert the bit through the hole on the other side and drill through. Use a knife or file to deburr the holes.
The second method, which is a bit more popular, is to slip a piece of pump outlet hose over the barrel. This so-called "barrel condom" provides a hard silicone layer of protection. Think your stainless barrels will be okay? Think again! I've had several stainless barrels dented by a bb hit. Using one of these methods, you will be sure to avoid a sudden jam at the worst possible time.
After installing the brass over your gun barrels, be sure to install other protection over the remaining gun parts. This could include securely mounted resin turrets, pvc barbettes attached to the turrets or the decking, etc. Be sure you can make this arrangement water tight. Happy shooting!
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