Positive flotation in an alloy boat?

General boating discussion
Toonseskat
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Joined: Sat Mar 26, 2016 4:57 pm
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Positive flotation in an alloy boat?

#1

Post by Toonseskat »

What is the best way to provide positive flotation to an older alloy boat?
kmorin
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Re: Positive flotation in an alloy boat?

#2

Post by kmorin »

toons' could you define 'best' in your question? and "older aluminum boat" ? Not much to go on!!

If its on old Lund or Gregor perhaps a Bayrunner? I think just putting in replacement foam blocks might be the ticket? On the other hand not knowing - what is best and the boat's pedigree- well that makes any answer; out of context?

Cheers,
Kevin Morin
Kenai, AK
kmorin
Toonseskat
Posts: 7
Joined: Sat Mar 26, 2016 4:57 pm
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Re: Positive flotation in an alloy boat?

#3

Post by Toonseskat »

Maybe I should have asked; what type of flotation (if any) is usually installed in welded plate aluminum boats?
kmorin
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Re: Positive flotation in an alloy boat?

#4

Post by kmorin »

toons! Much better question. Plate boats over 20' LOA don't as often have foam either cast or poured/sprayed as its not required by reg.s when the boat is that long or longer.

Others who use foam instead of (or in addition too) just air testing the voids for weld integrity (which should be done even if foam is used- perhaps more so?) either pour a liquid mixture that foams up to fill, usually a polyurethane type of foam OR they cast blocks of different foams to put in the voids before sealing up the deck welding tight.

Poured foam has lots of disadvantages that the search function here will turn up, it can break down into some pretty nasty corrosive materials, inside a void, and promote a couple other types of corrosion if there's any water in the void with the foam?

Styrene plastics either cast of glued into a stack block, the shape of the void, is reasonably inert in regard break down. But if left to lay flat to the surfaces inside a void could promote crevice corrosion if some moisture were present.

Air is the most effective and least expensive way to 'float your boat'; but is considered a reg. problem under 20'LOA; The regulatory question is just little on the absurd side- if you air test a void to keep water out, and the void holds air pressure, what water is going to get in to sink the boat? We're not talking Lunds that you can puncture with a claw hammer- the bottom of may plate boats will stop a .38wad cutter from arm's length. How the CG and Co. figure these boats are at risk with air voids is not part of rational explanations- it's just the way of an over-regulated society.

Short and sweet but with some use of the Search function- I think you'll find lots of different discussions involving this 'bush' we've beat around- I'd expect much more detail. Also might find some who've cleaned up after a foamed bilge or some other foam that could help give some perspective?

Cheers,
Kevin Morin
Kenai, AK
kmorin
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