Boat Insulation?

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teensailer

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Hi folks, recently asked about checking whether the swing keel on my Swift 18 works in another thread and am also wondering about insulation.

The whole interior is stripped back to the fibreglass and we have the wall panels, just ply, but no insulation. I was gonna just buy some of that cheap foil bubble wrap stuff but not sure if it needs to be ‘marine’ grade or if that’s just the classic make it expensive because it’s for yachts?
Any recommendations for what to use or what brands?
 
People have used closed cell neoprene foam in small boats. It does not absorb water and adds to buoyancy in emergency. It is easy to cut and glue to the inside of the hull or whatever. It can be covered in vinyl or that van carpet stuff. Roger Waters used it in both Ming Ming I and II so it works in the Arctic.
Plastazote is the brand.
 
Foil insulation is okay on ceiling, plus ply panels for air gap.. Help reduce condensation and keeps heat in/out. Use hi-temp spray adhesive. Simpler is just fourway stretch van liner carpet. Use on ceiling and sides. Lots of YouTube guides for van conversation. Insulation optional as it’s not habitation.
 
Insulation on that type of boat is maybe OTT. The key thing is to hide the rough interior of the GRP and reduce the chance of condensation. As already suggested van lining material is good for this as it is eaasy to install and looks good.
 
wonkywinch said:
I have used TLX Gold (breathable membrane insulation) in house projects and was going to use it in an abandoned camper van project. Might be worth considering for the boat?

TLX Gold

There are problem cheaper clone products if you look somewhere like Loft Insulation | Roof Insulation | Insulation Superstore®
Click to expand...
Why would you want it to be "breathable"?

My boat has some (very "breathable") carpet on the ply bulkheads, which dont need insulation under any circumstances I can think of, but would seem like a very bad idea anywhere that does, since water vapour will pass through it and condense against the cold (hull) surface, creating a mould farm at the interface.

The hull is generally bare. I thought of maybe applying gelcoat in places to smooth it, making it more easily wiped down, with maybe some non breathable silvery bubble wrap stuff, "Gary Glitters Gondola" stylee.
 
Thanks for all the replies, maybe I should clarify a bit. We just need it to stop condensation between the ply wall panels which cover the open fibreglass rather than actually keep it warm(tho that would be nice, the boats so small it’s more like camping especially with four people in it!)

I will look at all these things as soon as I get a chance. I always thought that van carpet stuff would be a pain if it got wet but maybe I’m thinking of something else.
 
Condensation means a "wet" boat. Dry it out with a dehumidifier and then ensure you have plenty of ventilation with a through flow of air. The humidity usually comes from water in the bilge and damp materials such as bunk cushions so best to remove these during the damp winter months. Also worth considering painting the bare GRP with an anti condensation paint such as this midlandchandlers.co.uk/products/teamac-anti-condensation-galley-paint-white-1l-pa-210?srsltid=AfmBOoodXXslKOW-pvLLmYzG9ENpgjW2AFPpfA-L2BP-PesJXcNkvDBG
 
The boat had some polystyrene glued to the GRP under the ply so we thought we needed it. As there will be a minimum of three and a max of five sleeping aboard I think it may be necessary to have something to stop condensation building up behind the ply. But maybe that paint could do it?
 
Just remembered that we have that paint already in the inaccessible places like the end of the bunk under the cockpit seats so if I do the rest with that do you think that is going to be enough?
 
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