How light is lightweight, marine grade concrete for boat building?

Question

I am considering to cast myself a planing boat out of marine grade concrete - I know they use it for sailboats with displacement hulls, but would it work for a light boat, too?

Answer 1

What you might try doing is to cast into the concrete fillers that will make it lighter, so that it will have less weight to displace. I know that hollow glass spheres have been used (very tiny, a by-product of smelting fly-ash, oslt.)

I think you can also whip air into concrete while it is curing, then coat the finished product with a skin coat of concrete-epoxy mix or paint. If you cast in sealed air bladders (glass bottles, fused shut...? At least that way you are using recyclables) it may improve the floatation characteristics.

Answer 2

having built repaired sailed delivered and generally messed about with boats for 30 years in the Caribbean,,,,,,,I wouldn't.....concrete don't like being hit repeatedly by anything, let alone water at high speed....and it is almost impossible to repair when it cracks.........look at some other material.......plywood, glass/kevlar and epoxy.....ANYTHING other than 'crete....and remember, the cost of a hull is only about 25% of the finished product.....the engines, nav gear, seats, etc etc etc are the same cost in a concrete steel or glass or wood hull, so why "save" a few bucks up front on a technology known to not work?

Answer 3

relies upon at this sort of connection you're conversing approximately. in my opinion i might use purely screw clamped or crimped connections. i'm careful of solder because it could carry approximately stressful spots in the cord that are in possibility of interrupt later. (rather DONT use plumbers solder) help or enclose the wiring so it cant get snagged or fatigue with repeated flexing. Use stranded tinned copper cord. The tinning very much will develop the time in the previous the cord is going black & terrible. attempt to have finished runs of cord with out joints (extraordinarily in the bilges). Dont "daisy chain" products, rather run all cable back on your needed administration factor. Do an entire and careful drawing & label all of the wires completely. Use coloration coding on your wires. Dont place self assurance in the boat hull for the return wiring. If it is an alloy boat be very careful of allowing stray contemporary into the hull - you wont have faith how rapid galvanic corrosion may well be!