Anyone got any tips or info on insulating a steel yacht? I've been told to use spray-on foam, not to use spray-on... use eps foam... use xps foam... etc. Also been told there's nothing you can do to stop condensation and insulating will only retain and hold the moisture and rust you from the inside out. Help me please!!
With a steel yacht you want access to all areas and I mean every square inch, so spraying something on is a huge no no in my books.
By posting that you consider that you may spray something over the steel kinda has me very concerned that you haven't checked every square inch of your hull inside and out. There is many nightmare stories of new owners who bought a steel hull held together and floating thanks just to paint. 
www.thecoastalpassage.com/rust.html
Thanks dinsdale... you're not the first to suggest that!! 
slammin... I'm not keen on spraying the hull with foam at all. One idea I had was getting hold of some air cell insulation (that's sandwiched between aluminium, with one side being sticky) and sticking that to the inside of the hull. But I don't think that's going to solve any condensation issue, only make it worse by keeping any moisture between the steel hull and the insulation. Or is it? Maybe if any condensation occurs it would be within the air cell part of the insulation, would be away from the steel hull and would dry with some light air flow.
The hull is in really good shape (only 14 years old), just a couple of light spots that need a scrub with a wire brush then some etch primer. I just want to ensure that everything is ok, looking for peace of mind to know she'll be right. (And yes, I've read the coastal passage article before and I'm nowhere near that type of problem thank goodness!!)
yeah id tend to stay away from the foam idea. better off to build it into the joinery work. is it for noise or temp or both? mind you mine was a solid grp floaty thing, not a huge fan of foam sandwich.
I have just come across this post on insulating a steel yacht. To eliminate condensation!? I have a steel yacht and I do not know what condensation is. People paint steel yachts white to make them cooler--and make condensation! Paint your hull a dark colour and condensation occurs as often as the sun rises in the West. The laws of physics relating to surface temperature, heat conduction, humidity etc. make condensation a non event.
I am not sure the dark colour option is such a good idea.
Knew a bloke that painted his fibreglass hull black and all his lockers were like ovens.
Good ventilation has to be the best solution. Some people glue carpet to the inside which seems to work. Spray foam has to be the worst solution.
My lockers are not noticeably hot because they are adequately ventilated. Carpet is not a solution, giving similar problems to foam. Ventilation is not a solution, it is an attempt to lessen the problem. A steel hull, painted a dark colour (it can be a long way lighter than black) absorbs heat, is always, therefore, at a higher temp than the surrounding air and being a good conductor the inside surface is the same temp. Condensation cannot happen. Any other "solution" is trying to alter the laws which make the world go round. End of story.
Yes, a dark painted steel hull is hotter than a white paint job but my hull is 27yrs old and in very good condition. If you want the advantages of steel-and they are many-it is a personal choice to have or not have interior condensation.
I will post some photos but it will take a day or two to organise.How bad was your damage Cisco? The last couple of years I have been horrified by the carnage up and down the coast.
I run a Delonghi Dehumidifier and it is amazing the amount of moisture the thing can draw from the air.
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