collision bulkheads/ 2 part foam

[rosslora]

Hello again. I am thinking of installing collision bulkheads in my Piver Trimaran. I would make the bulkheads from ply and have been wondering what to use within the 'space' created.
Has anyone had experience with two part polyurethane foam? Where does one buy it, and how is it used.
Thanks in advance for any help.
Ross

 

[PaulJ]

A two-part Poyurethane foam called "Handi-Foam" is supplied by Marine and Industrial Sealants (01692-538263). I haven't seen it used to fill a large space but a friend of mine used it to insulate the inside of his steel boat to a thickness of about 2" and he spoke very highly of it. I suggest you give Marine and Industrial a ring, they are very helpful.

 

[jollyjacktar]

Sometimes absorbs water

Check this out very carefully, it is not waterproof, it is not a sealed foam and it just occupies the space.

I had a 14' sailing dingy, double skin GRP with voids filled with that foam stuff. I could not understand why the boat was so heavy. Eventually cut a hole and found it totally saturated with water, which would not drain out due to capilliary attraction. With a great deal of effort and some home made electric drill attachment gadgets I eventually removed most of it. Replaced it with blocks of polystyrene foam shaped and jamed in and as well some sealed plastic containers etc and also fitted some drain plugs. Then if leak persisted or damage occurred the integrity of the floatation would not suffer and hopefully I would have sufficient floatation remaining.

 

[kgi]

What jolly jack tar says is absolutely true, but if you incorporate an inspection hatch in the top section of the bulkhead, a small drain valve in the bottom, and you only put enough foam in to come up about18 to 24 inches above the water line it will do fine, after all its only got to get you home in the event of a collision then you can dig it out repair, refill with foam and off you go again, i have a catamaran and this is what is in my boat, its not high tech/high spec but it works, as long as you are aware that the foam does absorb water you will be fine PS it was done on some of the earlier glass cats so the bows didnt collapse because the glass was so thin, the foam was there to stiffen it up!!!..........keith

 

[chippie]

I am about to replace some decks on my trimaran and investigated using closed cell foam for the enclosed area under them. I had a price quoted that was far too expensive for the half a cubic metre or so that I wanted. I dont know where you are situated, but I looked through a trade directory to find a resin and chemical supplier near me. Closed cell foams are supposed to be ok for this job.

Cheers

 

[rosslora]

Hello Chippie,
My tri is actually in Queensland Australia, and I am working offshore Borneo. Because its an older Piver I thought I would increase the buoyancy at the same time as have collision bulkheads.
The Chris White book recommends some sort of extra buoyancy in case the unthinkable happens and you flip. Because Arthur Piver was lost at sea, every second post on Google Groups throws mud at tri's and especially Pivers.
To make things even more interesting I will be single handing too!
Ross

 

[PaulJ]

Just a thought...... I'm afraid I don't know the boat you are talking about but could you fill the compartment with a large plastic bag/bags filled with those wretched little polystyrene lumps that are used for packaging? Alternatively, could you stuff the whole void with bubble wrap?

<P ID="edit"><FONT SIZE=-1>Edited by PaulJ on Thu Jun 27 09:14:38 2002 (server time).</FONT></P>

 

[kgi]

Us multihulls float just as well upside down as we do right way up, because we do not have a weighted keel hanging out of the bottom the chances of us sinking are quite remote,bouyancy fore and aft just gives us that much more time in the event we collide with something, my boat has padeyes fitted between the hulls so you can tie your dinghy there, if you have an inboard engine then bouyancy in the stern is a must, after all if you can keep the engine/batteries above the water you are in with a fighting chance.................cheers.....keith