I have started work on the ship this weekend, primarily figuring out the rib layout and a transport cradle for the ship (will add pictures soon!). I ran into a problem with ballad ting though. I loaded the ship with about 35 pounds in a bathtub, but the waterline was almost at the hull top! Should I just use the waterline on my plans, or should I ballast with less weight?
I know that hull from strike has been shortened, but I can't imagine it would make that much of a difference. Hopefully you just forgot to account for the weight of the hill like Nick suggested.
I did account for the weight of the hull, it was about 4 lbs. Another thing I might add is that I used water as a ballast because I have not gotten around to finding something like lead shot. Sorry I couldn't add any photos so you can understand the situation, I was jumping in and out of the bathtub, and I didn't want to get my phone wet.
Meanwhile, as I am trying to figure out how to find the waterline, I decided to work on the travel case for the KGV (something that I actually know how to do). First, I got a couple nice pieces of white oak, one 1"x12"x6' to make the baseboard, and 3 1"x4"x12" pieces to make the ribs. It's nice wood, even if a bit expensive. Next, I traced out 3 ribs to add to support the hull, and cut them out with a jigsaw. I am now in envy of all the people lucky enough to have something like a CNC machine or a stationary jigsaw! Note that the third rib is broken because cutting a thin piece with a jigsaw is hard! Here's a nice photo of the cleaned-up hull sitting in the transport case. I still need to sand the whole thing into shape before screwing, gluing and staining, but it looks nice!
Make sure the ribs for that travel case line up with ribs on the model. Otherwise they'll be pressing directly against balsa wood, with potentially disastrous results. Looks good so far!
I have not planned out where the ribs on the ship go, but I will be sanding the ribs on the travel case to make them much larger than the hull, and then I will fill that area with something soft like foam or cloth.
I have seen in a couple of other builds a way of finding the waterline by filling the hull with water instead of putting the hull into a tub. Can somebody explain how to do this?
I've heard of people weighting their ship with water to get the desired running weight, and then putting the hull in water. But as far as I'm aware there is no way to get the correct floating waterline by just adding water into the hull.
I just poked around the forum a bit more to find the original post that I got the idea from, which then lead me to http://www.strikemodels.com/blog/. If you scroll down about halfway through the blog, there are detailed instructions on how to fill the hull with water to find the waterline. I will post pictures of this process since I was unable to successfully float the hull to find the waterline, and now I can't even access a tub big enough to float.
Keep it simple. While there can be different ways to do the same thing, I suggest the tried and true: 1. Ask here for the ideal weight to battle 2. Fill the hull with the weight (lead, batteries, whatever). Subtract the weight of the hull when filling it 3. Drive to a small pond, pool, cement pond, whatever. If you want, go to a store and get an inflatable pool, cheap one will work just fine. 4. Float it and use a crayon to mark the waterline 5. Post pictures before you cut and ask questions.
I've used the fill the hull method to get my displacement and it does work. Fill up the hull to waterline and weigh it, subtracting the weight of the empty hull to get displacement. There are two gotchas: - the method doesn't account for the displacement of the hull shell, so the measured displacement will be less than what you need to get to the waterline because you eliminated the hull weight (when subtracting the hull empty weight) and didn't replace it with water weight. - I was unable to get the hull full of water to balance on one scale. So I used two scales, one which was only good for 6.6 pounds, so it was a little tricky to get it set where I would not max out that scale. Plus with two scales it's harder to get the ship level. You can carefully measure the volume of the water you put in instead of using scales. Then it's one fluid ounce of water is one ounce of weight.
Thanks! I decided to use the hull fill method because where I currently am constructing, I don't have access to a tub big enough to float anymore. In addition to this, the weather where I live is currently prohibitive of outside testing. I decided to do the hull fill method instead. First, I taped the hull to the scale width because the hull expanded, and also because the water pushes out the hull. Then, I filled the hull with 52 cups of water, which was calculated from the hull weight and scale displacement. Then I marked the waterline, and transferred it to the outside. This worked a lot better than my disastrous previous attempt to float the hull.
Best advice on ballast is to always ballast light. It's easy to add more if things aren't precisely correct, but a potential PITA to remove it.
I have just about finished the travel case/dry dock. I will post pictures of it once everything has finished drying. In the meantime, can somebody give me a specific part number/link to the epoxies that I will need?
I use West Systems 105 resin and 205 hardener, its more expensive than polyester resin but in my opinion it holds up better. I like that I can use the pumps to get the proper mix ratio without counting drops for polyester resin, and the batch size is typically more closer to the amount of epoxying I want to do at a time. It's an expensive option, a 1 gal resin and 1 qt hardener, with a pump set ran me about $175. It has made it through one complete boat build and I've used maybe 1/3 to 1/2. I have found polyester resins to be hit or miss. I do not recommend the Bondo brand found at home depot/lowes for our application. Resin intended for marine grade applications is better, the gallon I just bought was about $65.
