PDA

View Full Version : Floatation



RayH
01-23-2003, 08:01 PM
I'm new to this site and impressed with the knowledge shared. I'm in the process of replacing the floor in my '73 Sidewinder. I'm about 3/4 complete on the removal stage and found no big surprises, the floor board was rotten and the floatation wet. Stringers look good. My question is on floatation and where to purchase it. Originally, the manufacture layed the floor in and injected the floatation through drilled accesses in the floor. Then glassed everything up. I plan the do that same, however I'm not sure what type of floatation to use or who to call. Any advise would be appreciated.......... :confused:

Reese
01-23-2003, 08:57 PM
Welcome aboard...

There are two basic schools of thought regarding the use of foam in boats...there are those that hate it, and those that really hate it.

Personally, I would probably take it out and not replace it.

On the other hand foam is a very low density (light) material that theoretically would allow you to use a thinner plywood for the floor.

If you do choose to put it back make sure to use two-part expansion foam...you can generally purchase it at the same place you get your fiberglass supplies or order it on-line.

Good luck...

Barefoot Bob
01-23-2003, 09:01 PM
I need to foam mine also and this is what a friend sent to me.

Try clear cote corporation in St. Petersburg FL. They manufacture a two-part liquid polyurethane CLOSED CELL foam.

wierdkid
01-23-2003, 09:48 PM
when you put the 2 part in seal up any areas you have to cut (the best sealer ive heard is polyurethane)

B.Mac
01-24-2003, 05:09 AM
You can ruin alot of hard work in a hurry by using just a hair too much.......I'm sure it contributed to the seperation of my stringers from my hull (done @ factory). Don't get open cell foam either.
B.MAC:D

RayH
01-24-2003, 12:29 PM
Thanks for the feedback......

Good point on the expansion of the floatation, how much does two-part closed cell expand? I would assume the manufacture has a formula to est the area your filling......?

I too hate the idea of floatation, (once wet, always wet) however,
it does provide some support to the hull and with it being under the floor I would suspect you get a drum effect without it (noise).

B.Mac
01-24-2003, 04:25 PM
These guys are wizards around here........somebody will have some kind of trick to prevent a blowout like relief holes or something?
B.MAC:D

Reese
01-24-2003, 05:22 PM
right here......:D :D :D

B.Mac
01-24-2003, 07:28 PM
Hey you could have gotten a couple more in there Reese!!!
Talk about overkill:D ;) :p
B.MAC:D

baddjonny
02-03-2003, 04:05 PM
Chopped too much wet foam out of rotton floors but everything still SOLID in my friends originaly owned t-box flippa ranger rick 23' thunderbird circa 1966. NO FOAM UNDER FLOOR.

rparis40
06-17-2007, 09:59 PM
:( hello every one...I am new to this ...i have a bayliner that I am working on the floor of...is it true that you cam leave the foam out of the floor? Will this not compromise the stability? If this is not true can some one please tell me what kind of foam I need to purchase and where I can get it? Thanks

davecharles
06-18-2007, 08:18 AM
Yes you can leave the foam out of the floor on a bayliner, you may notice a little more noise when you hit waves (drum effect). If you leave the foam out be sure to put flotation somewhere else in the boat. With no flotation under the floor the boat will sink like a rock if filled with water. You will notice little difference as long as the boat is high and dry. Some companies put the foam under the deck and gunwales where it has less tendancy to collect and absorb water. The flotation in the upper parts of the boat will help it remain upright if filled with water.
Dave

rparis40
06-18-2007, 11:02 AM
Thanks alot davecharles for your advice......but I am sorry to say that this is my first boat and I am a little ....boat illiterate...where can I get (flotation?) Is this a foam that is injected or is it something you cut to shape? Where do I find this stuff?

davecharles
06-19-2007, 07:54 AM
There are lots of places to get the 2 part foam. I see it on ebay (do a search under boat parts) or buy it from one of the fiberglass suppliers on the net (google search). I buy from Composites One but they are wholesale only and you probably dont need 10 gallons (would fill your boat from floor to gunwale with a large hump in the middle). The 2-4 pounds/sq foot will do nicely. I have also seen people make fiberglass covered boxes and fill them with sheets of construction foam and place them under the bow and at the corners of the stern to provide flotation.
Dave

rparis40
06-19-2007, 09:58 AM
wow....thanks alot for that information davecharles.....you really put me on the right track.....I appreciate the info.

Cobra1racer
06-19-2007, 04:32 PM
Dang dude them there holes is all over the place. Looks like a race car. You don't need that many holes. I used to build a tunnel boat and I filled the sponsons with the 2 part foam. 1/4" in a 16 oz cup and it would rize about 3" out of it. Secure the floor so the foam won't push it off the stringers and give you a bulge in the floor. Just put a few holes in, about 2"-3" and space them evenly. Mix up a quart and work your way from one end to the other. Shave off the stuff that pops out of the relief holes and then cover them with glass. Make sure that when you put in the new floor that you glass it in and cover all the areas around the edges, you don't want water finding it's way inside again. It's a piece of cake. That sounds good right now, with a cold class of milk.

captcarb
06-19-2007, 08:22 PM
The way to guarantee that you don't bulge the floor or worse is to lay the foam in before the floor and trim it flat to fit. Then install the floor.

If you must have foam.

jim

laserracer6
06-19-2007, 10:21 PM
just a thought but a mate of mine has a 17 ' race boat and he has filled under the floor with plastic milk containers with the lids on and used race tape to wrap them into bundles so they dont rattle
cheers dave

mr_velocity
06-20-2007, 02:27 PM
just a thought but a mate of mine has a 17 ' race boat and he has filled under the floor with plastic milk containers with the lids on and used race tape to wrap them into bundles so they dont rattle
cheers dave

I gotta find an old pic I have of an offshore boat that used ping pong balls. When he stuffed and blew the bow of the boat open there was balls floating all over the place

sho305
06-20-2007, 03:35 PM
I was going to do some boxes in my boat and never got to it. I was going to stuff them with 2ltr and 20oz bottles and foam them in. These boxes are under seat and covered with ply. Was also going to get some heavy plastic bags and line the boxes first. I figured that way I could just use the spray can foam.

tunnels
07-08-2007, 02:52 AM
Floatation and where should it be placed ?? Under the floor is not a good place if the hull gets full of water it will flip upside down and float that way, Under the side decks is almost the right place also the fore and aft decks but its best placed in the hull sides if its possible ,this will make the boat float higher in the water and help it float level in the water . I have worked on a completely automatic inflatable system for a few years that works wonderfully and solves all your floatation problems .
Check with the specs from the coastguard as to how and what etc .
Two part foams will soak water over a long period of time and add weight to the hull . The old thing of ping pong balls is still the best and lightest option apart from floatation chambers that have nothng inside them . Beware of temprature changes and the expansion and contraction and dont totally seal them up . The expansion and contraction thing can be used to drain any moisture by using a copper tube glasse and sealed around into the lowest point of the chamber then going up under the side deck with a180degree bend in the top . As the air exspands it forces any water out and as it contracts it draws in fresh dryer air untill next time it warms again . Someting for nothing so to speak