I need to start to consider how I'll mount the fin and bulb, and get it all straight, so I made a 3D modeled alignment jig: Ian Dundas in Scottland sent me pictures of his setup. I just bought a laser level too! He does amazing work and has been a great help in this project so far. There is also another jig featured on page 14 of the winter 2008 Canadian Radio Yacht Association (CRYA) newsletter that features one. It's by Lawire Neish. Read it here . I took both those designs and made my own version that features sliding cradles for the hull, a fixed waterline sight, proper depth to cradles for the bulb, etc... Most of the parts can be laser cut, and the two end pieces and the base can easily be cut on a tablesaw. It has fixed waterline sights that are 420mm above the top edges of the bulb sliders in the base. The fore and aft cradles can be slid up and down to adjust the waterline of the hull. You'll see that the overall interior length is 1003mm t...

I finally received my new IOM fin, bulb and rudder today! It was shipped from Australia from Radio Sailing Shop . So far they look great, but to be honest, I'm not entirely sure what I'm looking at. The IOM fin is long, thin, carbon-fiber, and very light weight. It only weighs 101 grams! This isn't the way it is in Vintage Marblehead or Star 45's. The rules say that the fin and bulb together can only weigh 2500g. The bulb is currently 2533 grams and it will need to be worked a bit to get its weight down. I intend to epoxy coat it and then paint it as well, so that will add a small amount of weight. There are clearly some parts of the bulb that need to be cleaned up, but overall it's a very nice mold! The rudder came with a piece of 4mm stainless steel shaft, but I'm going to use 1/8" stainless steel. 1/8" is 3.175mm and is plenty strong for both Marblehead and Star 45 rudder posts, so I'm pretty sure it'll hold up to this. 1/8" ...

For the past few weeks, I've been tinkering on making some male-molds for future ballasts. I've 3D printed two male-molds for Sun Wind HF style torpedo bulbs, one slightly smaller than the other to make a lighter weight bulb if desired. And then also I've worked on a shaped ballast mold for the current Wampum VM that I'm building. Today, I finally took a big gulp and filled the molds full of refractory cement. Now I'll let it cure for a few days and then attempt to take off the molds and see how they look. Then I'll let the cement cure for a few weeks, occasionally in a warm oven, to fully cure before I attempt to pour lead in them. Here are two pictures of the molds in boxes that I framed around them. They have also been smeared liberally with Vaseline as a release agent.  I'm going to wait several days before trying to remove it. Gulp... Here are the two molds after being filled with refractory cement. I bought a 25 lb. tub and used it all. I...

The past two days have been spent working on two things: Fairing the lead bulbs into the fin, and making a custom cedar stand to hold the hull. I said this in an earlier post, but the boat with fin AND servo tray, including batteries, weighs 14 lbs. 7 oz. The deck, finishing, and rig will add a few more pounds, but the whole thing should be under 20. From my understanding, that is respectable. Thoughts?! Fairing the bulb halves onto the fin: Two days ago, I pinned and epoxied the bulb halves onto the inner 1/8" plywood core of the laser cut fin. Then yesterday I started to fair it out by sanding the entire bulb with a random orbital sander. MAKE sure you wear a decent mask while doing this!! Lead is very dangerous, especially when sanding!! I shaped the two bulbs so that they matched each other and looked good with the fin. Then I added additional thickened epoxy at the seams, and at the transition from fin to bulb, and let that cure overnight. Last night, added more ...

Today I mounted the two lead bulb halves onto the fin. A 9/64" hole was drilled through the middle balance-point of the bulbs, and through the fin where they are to go. Then I removed the bulbs, mixed up epoxy and painted on the bulbs and the fin. Then I made thickened epoxy and put that on as well. The bulbs were placed on the fin and a 1/8" stainless steel rod was pushed through the holes to hold the bulbs in line with each other. When dry, the pin will also help hold the bulbs onto the boat. Also when dry, I will drill a second hole through the nose of the bulbs and use a second pin to better hold the two halves onto the fin. After that, then the fairing begins. Thickened epoxy galore! But it will smoothly fair the bulbs into the fin, and the bulbs to each other. Once painted it will look like one, solid unit. By the way, the boat with fin AND servo tray, including batteries, weighs 14 lbs. 7 oz. The deck, finishing, and rig will add a few more pounds, but...

I've been scrambling to find a properly sized Vintage Marblehead lead bulb in the 9-10 lb. range. They really aren't commercially available, so you have to find "a guy" - probably an old-school RC sailor who has done it all. I found that guy! The other day, I mentioned on Facebook that I was looking for a VM bulb, and a gentleman named Jeffrey Gros from the Chicago area contacted me about one. He had several aluminum molds bequeathed to him by a well-know RC sailor, and thought that one of them might work. Sure enough, one looks just about right. Today, he poured one for me! Now I have a "lead bulb guy"! Thanks so much Jeffrey! I can't wait to get them. One of the half bulbs weighs 4 lbs. 11.5 oz., the other weighs 4 lbs. 15 oz. Should be easy to clean them up and equalize the weight.  Here are some pics he sent: I'll make another post when the arrive, but they look great in the pictures. He says that one half is slight heavier th...