foam in hull or no foam

[Goose]

im in the middle of my build and am in a debate on weather to foam or not in the back on my flatwater boat.how much weight does the 2lb foam really add.if i dont go with foam i know my hull is sealed up very well and reinforced in the tray and back sides to give it the stregnth to hold up due to not having foam.just want other peoples opnions

 

[Frosty]

2lb/cuft * 4.5cuft = 9lbs
3lb/cuft * 4.5cuft = 13.5lbs
4lb/cuft * 4.5cuft = 18lbs

FL_Cracker doesn't use any foam in his surf ski...

I am planning to use polystyrene foam in mine. it's lighter, strong as hell and will NOT absorb water, but it comes in blocks that need to be cut and shaped to fit. I picked 6 blocks up for free from the local tractor supply store.

 

[tipafew]

I am in the process of re-foaming as well. Trust me....I have debated this. I have had too many people who's opinions I trust tell me I have to have foam. I reinforced the right side(roll side) and went with the 2lb foam. I also used the blue Dow insulation along the bottom. The Dow foam created a channel over the chine area. If I ever notice it is taking on water, I will add some drains and at least be able to get some of the water out. I don't want to re-foam any time soon. It sucks!

 

[yamaslut]

I used 2lb foam...

I say foam it.

 

[Mark44]

2 LB Foam.

Mark44

 

[Matt_E]

I'll be going with polystyrene.
Lighter than 2-part urethane foam, and does not absorb water.

 

[chad]

2 lb

 

[joe b]

Your short hull will be light on the nose. A little less weight in the tail might help it handle a little better. :dunno:

 

[#ZERO]

Use ping pong balls and polystyrene foam beads if you're worried about the weight.

 

[astral]

going with foam blocks and a little reinforcment..
2nd year with wet foam and I pressure tested my hull last year..

 

[astral]

Anyone know where and if you can get liquid polystyrene foam..?? I googled it with no luck...I know about blocks but is there a pourable version??

 

[Frosty]

Anyone know where and if you can get liquid polystyrene foam..?? I googled it with no luck...I know about blocks but is there a pourable version??

From what I understand, in it's liquid form it emits a vapor that is toxic and can kill you in short order. I don't think you wanna mess with that. I've found places that you can buy it by the drum though or 50 lb bags. but there is minimum order quantities as it's for industrial use. I don't think I need a pallet of 50 lb bags...

 

[GSO]

No foam for me, with drains one on each side. Air tight tray ,reinforced. If I have time im going to put it in my pool with weight to take the place of the motor and see if it will sink and if so how long will it take. Also I have DIVE GEAR (LOL ) You can also add a valve to keep presure in the tray area for extra floatation. Just my thinking

 

[Matt_E]

Pressurized air in the tray will provide less flotation than non-pressurized.

 

[ANT]

foam it.

 

[yamaslut]

Pressurized air in the tray will provide less flotation than non-pressurized.

why, because it's heavier????

 

[Matt_E]

Yup.

DISCLAIMER: I doubt anyone could feel the difference. The nerd in me just needs to point out this misconception.

 

[marz831]

So, in theory, if you created a vacuum in the tray it would float better?

 

[snowxr]

Well I'm gonna fill my hull with helium baloons, then! HA!! I'll be doing fwd rolls!

 

[tipafew]

I have a helium tank here at work. Maybe your on to something. I could fill up some atv tubes with helium and put them back there. You're right though. I might end up doing forward flips!
Watch.....someone will go and try this now