Question, what are people using as filler to form the water channeling in the bottom of the hull? I've seen all varieties, epoxy with balloons, balsa, balsa with the silicone self leveling concrete, pine, etc. What method are people using now a days in building ships?
do not use the concrete sealant for the love of God. one thing I've noticed lately has been the use of yoga mat materials and such. those puzzle foam floor mats work well.
Its not cheap, but Feather-Lite by smooth-on is one of the most loved options. Two part mix, is buoyant when poured and solidified.
Yoga mat / work mat foam is good for fiberglass and 3d printed hulls. For wooden hulls, you can use balsa wood. I also used epoxy with microballoons in a vac-u-gearing to fill in a few of the low areas where water liked to pool.
Can confirm the foam is really nice. I got 3/4' hard closed cell foam and its in the bottom of the Bismarck. It works really nicely. Easy to put it in. Easy to cut out if I need to change things.
if you're doing a wood hull, there's an option that combines both what @Kotori87 and @bsgkid117 are saying. I did the balsa-fill with Idaho, and after about a year of fighting the hull, Will came up with a way to fix the problems. using that fix on Idaho, I came up with the following which I will be doing on any future wood hull: 1: take the hull and sheet over the hard area. you can use balsa or basswood strips. just tack them to the ribs and go. 2: trim it to match the anchor strip you use at the top of the hard area. 3: fiberglass it. use tape to sheet the hull and float test it with all of the gear generally where it's supposed to be. figure out where the ballast needs to go. 4: measure out that ballast in #7 or #8 birdshot in little zippie bags. place it in the rib gaps til you have the boat properly balanced. 5: mix that birdshot with epoxy and smush it into place where it needs to be. then fill the rest with featherlite. 6: there is a way to pour to contour all the way up to the top of the hard area, and since it's hard AF for me to explain without pics, I'll likely do a thread on it when I build my next wood boat. it's weird but it works and makes the hull even more durable.
One thing to add to Anvil's method. Don't just put the lead-and-epoxy mixture directly into the boat. Put some saran wrap or other plastic down first (or mold releasing agent, if you have it. I didn't.) and THEN smush the lead-and-epoxy mixture in. You'll then be able to remove the ballast so your boat is lighter when working in the shop, if you make changes that affect ballast, etc. Much easier to snap off a piece of lead that's in your hand than to try and chisel or dremel it out.
