Foam Questions

mcbroomsear

Seaman Apprentice
Joined
Jun 18, 2008
Messages
39
OK:

I've been reading up on the polyurethane expanding foam. I will be replacing most of my foam on my restore job and wanted to make sure I've got this right.

In 2lb foam most sites I've read say it provides 60lbs of floatation. I'm taking this to mean that it displaces 60lbs of weight. Is this correct? It seem like a high number for such a small quantity.

Secondly.

The boat I'm working on is pretty old and came with the bare bones set up by todays standards. I'll be adding some additional things like extra deep cycle batteries, trolling motors and more space for gear storage. Can adding additional foam provide additional bouancy to offset the weight of these items? I will never exceed the maximum weight limit of the craft as listed on the placard but was just wondering if this will counteract some of the extra weight in terms of the new thingy's I'm installing.

Lastly: Will installing this foam in the wrong places cause my boat to float, run or move in a manner which may be unsafe? I've looked at other boats and the foam usually sits along the last stringer at each edge. Will putting foam in the center or other areas cause those areas to react differently while the boat is sitting in the water?

Thanks!
 

NSBCraig

Lieutenant Commander
Joined
Aug 21, 2007
Messages
1,907
Re: Foam Questions

Yep 60 lbs of floatation = 60 lbs

What you should need is the same amount of floatation your boat came with, the added weight just means you can't carry as much stuff.

As for where to put it it only matters if it is adding structural strength to the hull if not put in anywhere ( think about the gunnels )

There a re a lot of threads with a whole lot of info on floataion foam on here look around you'll find what you need to know.

Good luck
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,148
Re: Foam Questions

Can adding additional foam provide additional bouancy to offset the weight of these items?

Ayuh,....

You don't seem to understand Displacement,+ Buoyancy,....

Adding Foam, inside the hull Only adds Weight, when the hull is floating normally....
Extra Junk, whether it's batteries, motors, fishing gear, or even Foam, causes the hull to float lower in the water, wherever the More weight is, it floats lower there.......
Period.......

Adding Foam only floats more weight, After the hull is totally Flooded......
 
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