Interested in insulating my hull for winter live-aboard. Right now I have a solid fiberglass hull providing little insulation. I have looked at the options such as spray in polyuretherane, polyethylene sheet (such as ethafoam), polystyrene, cork, and Armaflex AP. What works best and is reasonable to install? Is there a better option I missed? I'm currently leaning towards 1" Armaflex which provides an additional R value of ~3.8. It is paintable to a white color via company specific paint. Total cost is looking to be ~$2.00/sq ft. Does the stuff hold up? Does it have to be covered with a protective layer of wood or fiberglass to prevent damage to the material? How well does the adhesive recommended work with bonding to fiberglass? Heat is either from shore power (1.5KW) or a Webasto 2000 heater. This yields a max heat influx of ~5000Btu/hr. Does anyone know the R value of solid fiberglass for the hull? I'm assuming it to be rather low.
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Similar Project
Have you seen this link here on sailnet? This is similar to what I'm doing to my O'Day 25.
Have you seen this link here on sailnet? This is similar to what I'm doing to my O'Day 25.
insulation...
After having lived aboard in the Pacific Northwest for 10 years my advice would be the spray foam insulation - if it works for you. The biggest problem is accessing the inside of the hull without tearing the interior of the boat apart. I have tried the glue in urethane foam which worked to some extent but you will end up with voids that are impossible to get to and the resulting condensation. My other recommendation would be to install a hot water heating system - more uniform heat and more reliable than forced air. (ITR makes a Hurricane heater that is built for the marine environment and very reliable.)
After having lived aboard in the Pacific Northwest for 10 years my advice would be the spray foam insulation - if it works for you. The biggest problem is accessing the inside of the hull without tearing the interior of the boat apart. I have tried the glue in urethane foam which worked to some extent but you will end up with voids that are impossible to get to and the resulting condensation. My other recommendation would be to install a hot water heating system - more uniform heat and more reliable than forced air. (ITR makes a Hurricane heater that is built for the marine environment and very reliable.)
Re: insulation
In your case Lyle, how has the spray foam insulation been holding up? I keep reading it absorbs a bit of water and often can begin to mold. Also, the voids you are referring to were between the foam and hull or in between the edges of the sheets of foam? Herb, how has your O'Day 25 turned out? Is it at all reasonable to glue rigid panels onto the hull? The reason I looked at Armaflex is because of the flexibility for contoured surfaces. Has this been a problem? And I'm assuming you are covering it with wood strips like the link you sent.
In your case Lyle, how has the spray foam insulation been holding up? I keep reading it absorbs a bit of water and often can begin to mold. Also, the voids you are referring to were between the foam and hull or in between the edges of the sheets of foam? Herb, how has your O'Day 25 turned out? Is it at all reasonable to glue rigid panels onto the hull? The reason I looked at Armaflex is because of the flexibility for contoured surfaces. Has this been a problem? And I'm assuming you are covering it with wood strips like the link you sent.
Spray in foam
From what I've read, cruisers who put in long miles under rough conditions will eventually experience the sprayed foam pulling away from the walls and perhaps getting mold back there, but it takes quite a while, and if you're not putting her through those paces it may not happen for as long as you own her. Given how most fiberglass liners are made I doubt you could even get at many areas other than by drilling holes and spraying into them. For areas where you want to use sheets you might try wrapping or laminating them tightly in plastic and taping the plastic rather than the foam dirctly to the wall.
From what I've read, cruisers who put in long miles under rough conditions will eventually experience the sprayed foam pulling away from the walls and perhaps getting mold back there, but it takes quite a while, and if you're not putting her through those paces it may not happen for as long as you own her. Given how most fiberglass liners are made I doubt you could even get at many areas other than by drilling holes and spraying into them. For areas where you want to use sheets you might try wrapping or laminating them tightly in plastic and taping the plastic rather than the foam dirctly to the wall.
spray foam
The spray foam held up well - no mold or water absorbtion issues that I could see. This also was done though when the boat was built - which for obvious reasons is the best time. If it is done on an older boat you would have to make sure it adheres well to the hull for it to work well. The voids I was talking about on the glue in foam were between the sheets although I am sure there were some behind as well where the foam did not adhere properly
The spray foam held up well - no mold or water absorbtion issues that I could see. This also was done though when the boat was built - which for obvious reasons is the best time. If it is done on an older boat you would have to make sure it adheres well to the hull for it to work well. The voids I was talking about on the glue in foam were between the sheets although I am sure there were some behind as well where the foam did not adhere properly
Not There Yet
Jed, I haven't gotten to that point yet on my O'Day 25. In my case, I had considered replacing the liner for a while. Earlier this year, a rotted bulkhead let a chainplate fly loose, bringing the mast down, pulling a hole in the deck, etc. I decided to combine that repair along with the liner replacement. As was mentioned earlier, to get to anything, you just about have to disassemble everything. That lead to me deciding to completely remodel the whole interior. Right now, bulkheads are in, new chainplates are in, deck's repaired, and the mast is back up. Next week, I start glassing in the ribbing. The vertical area of my boat is not that large, so I think foam sheets will work fine. Also, as I disassembled everything, I noticed the rib running the length of the hull was formed basicaly the same way - foam covered with fiberglass.
Jed, I haven't gotten to that point yet on my O'Day 25. In my case, I had considered replacing the liner for a while. Earlier this year, a rotted bulkhead let a chainplate fly loose, bringing the mast down, pulling a hole in the deck, etc. I decided to combine that repair along with the liner replacement. As was mentioned earlier, to get to anything, you just about have to disassemble everything. That lead to me deciding to completely remodel the whole interior. Right now, bulkheads are in, new chainplates are in, deck's repaired, and the mast is back up. Next week, I start glassing in the ribbing. The vertical area of my boat is not that large, so I think foam sheets will work fine. Also, as I disassembled everything, I noticed the rib running the length of the hull was formed basicaly the same way - foam covered with fiberglass.
Bulkhead replacement...
How'd the bulkhead replacement work for you, Herb? What wood did you use and did you seal the bottom prior to the install? Any helpful hints? Mine is on borrowed time as it is. Thanks!
How'd the bulkhead replacement work for you, Herb? What wood did you use and did you seal the bottom prior to the install? Any helpful hints? Mine is on borrowed time as it is. Thanks!
Bulkhead Replacement
Actually, it went very well, at least so far. I used 1/2" marine grade luan plywood. I found out later that the original wood was not marine grade plywood, so I guess it's an "upgrade". I decided not to stain the wood or put any veneer on it. However, when I sprayed on the sealer, it got a little darker. I'm not satisfied with the look of the sealer, so I'm ging to clear varnish it a few more coats. But, just the sealer alone gave it a color that has caused others to ask if it's mahogany. The final result has gotten several folks to ask me to pick up the same wood for them next time I go to New Orleans (assuming that Riverside Lumber is back open by then.) Anyway, I didn't go to extrodinary lengths to seal the edges. I put a coat of gorilla glue along the edges. Sloppy, but I knew they wouldn't be visible. The upper portion of the bulkheads fit in a groove that I believe will be relatively dry. I think between that, and glue sealing the edges, it'll be fine there. The side against the hull I fiberglassed into place with 2 layers of weave and one layer of mat. the bottom edge I'm counting on the glue to be the seal. The sides on the inside, since they would be visible, were edged with oak on the starboard side, glued on (gorillia glue), then screwed in. The port side butts up against the compression post. On my old bulkheads, the only portions damaged after 30 years was the wood under the chainplates. The old bulkheads were attached the hull the same way I've done the new ones. Glassed on the sides, screwed to the fiberglass settee near the base. I'm not sure how they sealed the edges on the bottom, but they didn't look like they were sealed at all.
Actually, it went very well, at least so far. I used 1/2" marine grade luan plywood. I found out later that the original wood was not marine grade plywood, so I guess it's an "upgrade". I decided not to stain the wood or put any veneer on it. However, when I sprayed on the sealer, it got a little darker. I'm not satisfied with the look of the sealer, so I'm ging to clear varnish it a few more coats. But, just the sealer alone gave it a color that has caused others to ask if it's mahogany. The final result has gotten several folks to ask me to pick up the same wood for them next time I go to New Orleans (assuming that Riverside Lumber is back open by then.) Anyway, I didn't go to extrodinary lengths to seal the edges. I put a coat of gorilla glue along the edges. Sloppy, but I knew they wouldn't be visible. The upper portion of the bulkheads fit in a groove that I believe will be relatively dry. I think between that, and glue sealing the edges, it'll be fine there. The side against the hull I fiberglassed into place with 2 layers of weave and one layer of mat. the bottom edge I'm counting on the glue to be the seal. The sides on the inside, since they would be visible, were edged with oak on the starboard side, glued on (gorillia glue), then screwed in. The port side butts up against the compression post. On my old bulkheads, the only portions damaged after 30 years was the wood under the chainplates. The old bulkheads were attached the hull the same way I've done the new ones. Glassed on the sides, screwed to the fiberglass settee near the base. I'm not sure how they sealed the edges on the bottom, but they didn't look like they were sealed at all.
Re: Not There Yet
Herb, Am I correct in assuming you are going to put down polyisocyanurate foam board with an Al covering on it? The reason I'm wondering is because what I can find on that foam is that it has to be sealed from water due to its hygroscopic nature. Are you planning on sealing it in? Or am I mistaken by the pictures and you're opting for an expanded polystyrene which does not have this problem? The best information I can find on insulating a boat and the types is summarized by the Glacier Bay company (link below). They just don't cover types such as Armaflex which would be easier to apply on an existing boat. I keep steering away from a spray in foam due to the complexity of its installation on an older boat. Rich, I don't follow what you're saying about laminating the sheets and taping them in. Is this for moisture reasons? To keep the resin from melting the foam? Taping? You mean fiberglassing them in?
Herb, Am I correct in assuming you are going to put down polyisocyanurate foam board with an Al covering on it? The reason I'm wondering is because what I can find on that foam is that it has to be sealed from water due to its hygroscopic nature. Are you planning on sealing it in? Or am I mistaken by the pictures and you're opting for an expanded polystyrene which does not have this problem? The best information I can find on insulating a boat and the types is summarized by the Glacier Bay company (link below). They just don't cover types such as Armaflex which would be easier to apply on an existing boat. I keep steering away from a spray in foam due to the complexity of its installation on an older boat. Rich, I don't follow what you're saying about laminating the sheets and taping them in. Is this for moisture reasons? To keep the resin from melting the foam? Taping? You mean fiberglassing them in?
Learning as I Go
Jed, I have to defer to you on this one. Until I hit this thread, I was just going to go buy a couple sheets of foam insulation. Sounds like 1> you know more about what to use than I, and 2> you may have saved me from making a mistake. I'll definitely keep this info in mind when I go to buy the foam, and appreciate the info you've given me.
Jed, I have to defer to you on this one. Until I hit this thread, I was just going to go buy a couple sheets of foam insulation. Sounds like 1> you know more about what to use than I, and 2> you may have saved me from making a mistake. I'll definitely keep this info in mind when I go to buy the foam, and appreciate the info you've given me.
Don Casey's Book
Jed, I just reread the portion of Don Casey's "This Old Boat" where he discussed building a boat ceiling, and found a line I had missed before. He said "A new product fom Texcon called Reflectix - a mylar/bubble cap sandwich with an R-value of about six for 1/4-inc thickness - is finding a loyal following." Have you heard anything about this? I saw that Home Depot carries it, so it must be fairly easy to find. I'm thinking I will probably use regular foam to build the ribs, with mat and epoxy surrounding them, they should be plenty watertight, then using the Reflectix between the glassed ribs to just give it more insulation. Thoughts?
Jed, I just reread the portion of Don Casey's "This Old Boat" where he discussed building a boat ceiling, and found a line I had missed before. He said "A new product fom Texcon called Reflectix - a mylar/bubble cap sandwich with an R-value of about six for 1/4-inc thickness - is finding a loyal following." Have you heard anything about this? I saw that Home Depot carries it, so it must be fairly easy to find. I'm thinking I will probably use regular foam to build the ribs, with mat and epoxy surrounding them, they should be plenty watertight, then using the Reflectix between the glassed ribs to just give it more insulation. Thoughts?
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