New? idea for flotation

timothyl

Seaman
Joined
Aug 22, 2003
Messages
62
I am replacing the floor in my 1966 Glasspar Seafair Sedan and have read many previous posts concerning the use of foam. It seems that many individuals advise against foam because it does not allow water to drain. <br /> I have an idea that may allow the use of foam and still allow water to drain. What if I took 1" pvc pipe and drilled numerous holes in the pipe, glued it to the bottom of the hull next to the stringers, and then placed foam over the pipe. This should allow any water to drain yet still allow the use of foam. This would be the same concept as draining soil and using rocks to allow drainage.<br /> I would appreciate any input.
 

Uncle Dave

Petty Officer 1st Class
Joined
Jun 10, 2003
Messages
240
Re: New? idea for flotation

I have thought of the same. I am finishing an alum hull that was ruined by water trapped between foam and the hull. I am not going to place a drain as I believe capilary action would not allow much water to drain out. However it would not hurt to try the pvc pipe. I would crush or scred some foam and place around the pipe to keep the foam pouring process from filling the holes in the pipe. Also a valve or removeable cap at the bilge end. Water in the bilge would turn the pipe into an irrigation pipe. After removing the boat from water then open the valve and let drain. <br />Keep us posted if you try<br />Thanks,<br />Fitz.
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: New? idea for flotation

Bingo! Tlands, I think you have swerved into the perfect solution to floatation. Line the bottom of the boat with peagravel then apply the foam over the top of it. :D Of course, it only makes sense. Everything from water filtration to drainage behind block walls uses gravel. The added benefit would be lowering the center of gravity.
 

airman

Petty Officer 1st Class
Joined
Aug 9, 2003
Messages
332
Re: New? idea for flotation

In my experience, it won't work as well as you hope. I'm replacing some flooring for the 2nd time in 5 years. I put in drain holes the last time. The problem is that the water comes in from the top and gets trapped ON TOP of the foam. It never gets to the bottom where we put our beautiful little holes. Eventually some makes it down but not before it rots all the wood first. What I'm doing now is sealing the wood. Others have suggested sealing with an uncatalyzed (I would lean towards a very lightly catalyzed) coat of polester resin, giving it plenty of time to soak in. I'm going with an epoxy sealer, even though it forces me to use epoxy as a resin too. I did the transom that way and it stood up perfectly right next to totally rotten (unsealed) wood. I'm also going to invest in a really good custom cover for the boat. The polyester probably works fine but twice is enough for me, I thought I had it last time with the drain holes idea.
 

two2canoe

Seaman Apprentice
Joined
Oct 4, 2003
Messages
48
Re: New? idea for flotation

I put a floor in my '59 Crestliner last year. I have had the boat for 20 years and this is the first floor I have had to do. The boat is stored outside. Sometimes covered, sometimes not. I fish in the rain. The hull leaks around the drain plug. Bilge pump get's the water out. The foam is big blocks of solid foam kinda like styrafoam. It doesn't touch the bottom of the floor, there's plenty of space for the water that gets in to run back to the bilge pump. The foam is dry and not waterlogged. The old floor got soft around the holes where my seat pedistals were bolted on but that took 20 years. I bet that the boat builders went to the pumped in foam to save time and effort putting it in. Why not big blocks of styrafoam loose under the floor like my old Crestliner? Solves the water retention problem.
 

gewf631

Chief Petty Officer
Joined
Mar 4, 2003
Messages
489
Re: New? idea for flotation

The floor in my mid-70's Starcraft (aluminum) is the same thing - big blocks/strips of styrofoam.<br /><br />I put a belly tank in when I did mine, and I was worried about the weight of the tank on the ribs, and the potential of breaking the tank. So I used a length of PVC run down the middle, but only after I sliced-out a strip of the pipe - if you look at it length-wise, it looked like a "C". Similar idea to tlands.<br /><br />I realize aluminum boats don't have the same needs as glass ones, but after 25 years, that foam was still as solid and dry as the day the boat was built.
 

catfish1

Senior Chief Petty Officer
Joined
Jul 23, 2003
Messages
683
Re: New? idea for flotation

what i did when i poured foam was; cut a board to go between the stringers for the desired space between the bottom of the hull to the foam, i put a trash bag over the board and laid it down in the vee of the hull starting from the stern, and with a slight tilt to the stern, i poured the foam on top of the board and had another board (also covered with plastic) to lay across the top of the stringers so when the foam expanded it stayed between the boards and left a nice space between the bottom of the hull and the foam, it also left a nice level surface to lay the plywood on. i had to stand on the top board to keep the foam from comming up. i just did it in steps. poured, then after the foam expanded fully i would pull the board out of the bag (top & bottom) and move forward until i got to the bow area, in the bow i poured the foam solid, all the way to the hulls bottom, because i knew for one, i would'nt be able to get the board out from under it. and two, water is'nt going to stay at the bow. what i ended up with was; space between the foam and the hull for water to run. and a nice level surface to lay plywood on to.<br />there are many ways to pour & mold foam, it just takes careful planning. :)
 

Jack Shellac

Lieutenant Commander
Joined
Aug 7, 2002
Messages
1,661
Re: New? idea for flotation

On a boat repair and upkeep show that I saw on TV a few years ago, the guy did exactly what you're talking about. He was rebuilding the floor and stingers and put a perforated PVC pipe right down the center in the bilge to let water drain out. Of course, I think the other guys are right in that the water has to be able to get down to the bilge to drain. Styrofoam blocks would be the way to go for this.<br /> Just remembered: "SHIPSHAPE TV" was the name of the show.
 

ED21

Master Chief Petty Officer
Joined
Aug 26, 2003
Messages
829
Re: New? idea for flotation

Shipshape TV is a great show. It's on PBS late at night usually in my area. They cover all sorts of boat projects.<br />If you use perforated pipe under the foam, I think a better solution would be to use landscaping filter fabric or tyvec wrapped around the pipe to keep the holes open & to allow water to drain through.
 
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