Home |
Search |
Today's Posts |
#1
posted to rec.boats.building
|
|||
|
|||
flotation Foam
Ok, I'm in the middle of a rebuild/repair on an aluminum boat. I just
jerked the plywood sole out of it in order to replace it with aluminum decking, and I found what looks like plant arranging foam between the ribs for flotation. It soure doesn't look or feel like a sealed cell foam. Its also quite a bit narrower than the space available. I was thinking about replacing it with foam that fits snug between the ribs to increase the flotation slightly, but I'ld like to use the best thing possible. Would styrofoam be more suitable? I know styro hardly absorbs any water at all. It lasts indefinitely as the flotation under docks as long as its not exposed to sunlight. . How about a poured foam? Are there any that form sealed cells as it hardens? Would it work here, or would it be too hard to get it level with the ribs so I can put in the new sole? I'm not sure I want poured foam in here anyway, as any water that comes in the forward deck hatches etc drain through the strength creases in the hull to the back of the boat where it can get kicked out by the bilge pump. I'm thinking if I can styro that its just the right thickness it will be the best foam replacement, but there is a lot more experience in this group than I have. Bob La Londe www.YumaBassMan.com |
#2
posted to rec.boats.building
|
|||
|
|||
flotation Foam
Subject
Pourable urethane foam, poured in successive pours. Bought mine from an outfit in West Palm Beach, FL. They shipped via UPS. Lew |
#3
posted to rec.boats.building
|
|||
|
|||
flotation Foam
|
#4
posted to rec.boats.building
|
|||
|
|||
flotation Foam
On Tue, 5 Aug 2008 20:50:00 -0700, "Bob La Londe"
wrote: Ok, I'm in the middle of a rebuild/repair on an aluminum boat. I just jerked the plywood sole out of it in order to replace it with aluminum decking, and I found what looks like plant arranging foam between the ribs for flotation. It soure doesn't look or feel like a sealed cell foam. Its also quite a bit narrower than the space available. I was thinking about replacing it with foam that fits snug between the ribs to increase the flotation slightly, but I'ld like to use the best thing possible. Would styrofoam be more suitable? I know styro hardly absorbs any water at all. It lasts indefinitely as the flotation under docks as long as its not exposed to sunlight. . How about a poured foam? Are there any that form sealed cells as it hardens? Would it work here, or would it be too hard to get it level with the ribs so I can put in the new sole? I'm not sure I want poured foam in here anyway, as any water that comes in the forward deck hatches etc drain through the strength creases in the hull to the back of the boat where it can get kicked out by the bilge pump. I'm thinking if I can styro that its just the right thickness it will be the best foam replacement, but there is a lot more experience in this group than I have. Bob La Londe www.YumaBassMan.com I have a "bolt together 3 part dinghy" that has styrofoam blocks glued under the seat as flotation and have seen encapsulated styrofoam used on other commercially made boats. Sometimes it is wrapped in plastic sheet and heat sealed. Remember that the foam is not what keeps you afloat it is a volume that weighs less then the water so it can be anything that doesn't absorb water. Re your other post about the transom. You have two forces acting on the transom. One, a bending moment due to the weight and thrust of the motor and secondly, a crushing force due to the pressure of the engine mount clamps or bolts. The first can be handled by designing a series of formers so that the former and the inner and outer skin act as a beam - obviously a number of formers. The second could be taken care of by either heavier - say double or triple skinned sections separated by a heavy former or even solid bar stock, or a heavy wall "box" section in line with the engine mounts. You would need to "taper" the support out so that you don't have a stress concentration which would cause cracking. Have a look at some Home built airplane sites to see how they handle forces imposed on aluminum structures. Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom) |
#5
posted to rec.boats.building
|
|||
|
|||
flotation Foam
Bob,
Be very careful with this. If you use polyurethane expanding foam, it is NOT closed cell and it will eventually absorb liquids. When it does, it is very hard work to remove. This kind of foam is very valuable on a steel boat because of condensation and rust. If you insist on using the stuff, you use a sealing paint for insurance. Styrofoam is good enough for your purpose, it is easy to both cut and glue and it doesnot absorb moisture. Steve "Bob La Londe" wrote in message ... Ok, I'm in the middle of a rebuild/repair on an aluminum boat. I just jerked the plywood sole out of it in order to replace it with aluminum decking, and I found what looks like plant arranging foam between the ribs for flotation. It soure doesn't look or feel like a sealed cell foam. Its also quite a bit narrower than the space available. I was thinking about replacing it with foam that fits snug between the ribs to increase the flotation slightly, but I'ld like to use the best thing possible. Would styrofoam be more suitable? I know styro hardly absorbs any water at all. It lasts indefinitely as the flotation under docks as long as its not exposed to sunlight. . How about a poured foam? Are there any that form sealed cells as it hardens? Would it work here, or would it be too hard to get it level with the ribs so I can put in the new sole? I'm not sure I want poured foam in here anyway, as any water that comes in the forward deck hatches etc drain through the strength creases in the hull to the back of the boat where it can get kicked out by the bilge pump. I'm thinking if I can styro that its just the right thickness it will be the best foam replacement, but there is a lot more experience in this group than I have. Bob La Londe www.YumaBassMan.com |
#6
posted to rec.boats.building
|
|||
|
|||
flotation Foam
subject
Two suggestions One: Stay away from pour foam. Particularly if it may get exposed to moisture. Use Styrofoam blocks or factory cast polyurethane foam blocks. Do not let anyone BS you. Pour foam will absorb water. Two: For your transom. http://www.coosacomposites.com/ This is a very strong product that can be bonded between two sheets of relatively thin aluminum. I would bond with 3M 5200 or a like product. Bostik 920 would be much cheaper and work just as well. I am sure some in this group would insist on epoxy. Good luck. |
#7
posted to rec.boats.building
|
|||
|
|||
flotation Foam
"FR" wrote in message
news subject Two suggestions One: Stay away from pour foam. Particularly if it may get exposed to moisture. Use Styrofoam blocks or factory cast polyurethane foam blocks. Do not let anyone BS you. Pour foam will absorb water. Two: For your transom. http://www.coosacomposites.com/ This is a very strong product that can be bonded between two sheets of relatively thin aluminum. I would bond with 3M 5200 or a like product. Bostik 920 would be much cheaper and work just as well. I am sure some in this group would insist on epoxy. Thank you. I had pretty much already decided to cut tight fitting sheets of styro to replace the nasty stuff below the sole of the first project boat. That composite from Coosa Composites sounds like exactly what I was looking for on the other. Thank you again. Bob La Londe www.YumaBassMan.com |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
looking for sheet flotation foam | Boat Building | |||
Flotation | Boat Building | |||
where2find->water soluble foam rubber adhesive OR a foam rubber cleaner not water based | Boat Building | |||
Flotation | Whitewater | |||
Livingston Flotation Foam-filled? | Boat Building |