Cool Ballast Idea

[wotan2525]

old thread....

I've actually played around with idea for quite some time. Full disclosure, I haven't actually done it. But when I get a new boat I might just try the theory on my current one.
I have an 86 supra pro comp.

So remove floor showing stringers braces, joints etc. Remove all wet foam.... face it its all soakin wet.
measure out all places were cross bracing is located.
now you build an integral alum tank. Sheet for the floor, the sides, and top. Replace wood cross bracing with alum plates welded to sides and floor.
before you weld them into the floor cut a few scallops on the bottom and couple though holes in the middle for water passage.
Have tabs on the walls at the top that when you set the slightly smaller lid on the tank it will sit on it nicely and allow a good clean weld.
Install a simple fluid level gauge.
have it vent from the front, big valves in the rear. cake.
how hard could it be?

I took a rough ROUGH calculation and came up with approx 2k worth of ballast. About 125 gallons a side.

Your calculations were pretty rough. 250 gallons = ~33 cubic feet. There's not that much room. Remove your floor and take some measurements with sand and tell me what you end up with.... It's a surprisingly small area and will get even smaller once you start installing tanks.

Also -- how do you propose to fuse your aluminum cross bracing to the hull? You say weld but the hull is fiberglass and the floor will (probably) still be wood. It gets very tricky, very fast.