insulation in a steel boat, to have or not to have

[48d north]

Hello All, This might be a deep subject but we are looking for all your great input, especially you steel boat owners. We think we have found the steel boat for us and are making the switch from FB. We now plan to cruise northern latitudes, high northern latitudes, and the captain has always wanted a steel boat anyway. (Steel is real, in his words). We thought we were knowledgeable about all aspects steel but upon the survey of this used boat we found the owners had removed all insulation when they took it back to bare metal and repainted/epoxyed. The boat is located near the St. Lawrence and apparantly this is common practice? Since the boat is well appointed inside the thought of tearing it apart to reinsulate is daunting. While I can handle anything the weather outside throws at us, inside I want some heat. Since condensation and inspecting the hull was a concern for the present owner for taking out the insulation (which was styrofoam ) what are we missing in this equation. Should we continue to search for another steel boat, think seriously about redoing this one or not even be concerned. Really appreciate your collective knowledge!

[bcguy]

I have sailed glass and steel. An insulated steel boat is a joy and if you are in a colder climate, adding a wood stove just makes life aboard all the better. I heat, cook, bake, dry on mine... lots of free wood in my cruising grounds. Google up yahoo groups origami steel boats and post your question there. Lots of tropical as well as northern sailors with insulated steel boats will be happy to answer your questions.

[unclemack]

Previous owners of my steel boat have installed some polystyrene (styrofoam) and some polyurethane foam in different areas.

Polystyrene gives off toxic fumes when it burns, which it does readily. That might be the reason it's been removed from the boat you're looking at.

I don't actually know of an insulating foam that's without issues so I've left mine alone so far.

My insulation is only between the frames. Condensation drips from any bare frames and hatch frames, glazed areas etc. in winter in the UK.

Sprayed-on closed cell foam is said to cure the condensation problem and keep temperatures liveable but the whole interior would need to be removed to spray the hull.

I've also read that, if not sprayed exactly to specification, the foam can out-gas and cause health problems in some people. Can't remember specifics though, sorry.

[Snowpetrel]

If you're going to cold places insulation of some sort is very important. Without it its like living in a freezer that when it warms up starts dripping all those icicles that formed under the lining onto your bunk and your books..

[Triumphant]

Originally Posted by Snowpetrel

If you're going to cold places insulation of some sort is very important. Without it its like living in a freezer that when it warms up starts dripping all those icicles that formed under the lining onto your bunk and your books..

And if you go to hot places like the tropics it is also needed otherwise it is like living inside and oven or under a hot plate.

We have 1 inch panels of insulation between the hull and the wooden lining

[Snowpetrel]

Originally Posted by Triumphant

And if you go to hot places like the tropics it is also needed otherwise it is like living inside and oven or under a hot plate.

We have 1 inch panels of insulation between the hull and the wooden lining

+1 I lived board snowpetrel1 for awhile before i insulated her. I froze in winter and fried in summer, mind you the head lining was out as well... i remember waking up in winter with frost on the inside of deckhead. In summer you could feel the heat radiating off the roof! I used to use a towel to wipe dow the roof in the morning.

Even with the 40mm polystyrene insulation I added you could still see condensation form on the lining where the frames were.

[markpierce]

Isn't insulation on a steel boat standard, and undoubtedly for a good reason?

[48d north]

We thought insulation would be considered a must as well, have been interested in the armaflex we've seen being used vs. the polystyrene so when the present owner mentioned the removal on this boat and a sister boat due to " the better to keep on eye on the hull" we were mystified. Thought maybe we didn't know all we should about insulation and steel. Thanks to all for verifying it should have insulation.

[TKDSailor]

Originally Posted by 48d north

Hello All, This might be a deep subject but we are looking for all your great input, especially you steel boat owners. We think we have found the steel boat for us and are making the switch from FB. We now plan to cruise northern latitudes, high northern latitudes, and the captain has always wanted a steel boat anyway. (Steel is real, in his words). We thought we were knowledgeable about all aspects steel but upon the survey of this used boat we found the owners had removed all insulation when they took it back to bare metal and repainted/epoxyed. The boat is located near the St. Lawrence and apparantly this is common practice? Since the boat is well appointed inside the thought of tearing it apart to reinsulate is daunting. While I can handle anything the weather outside throws at us, inside I want some heat. Since condensation and inspecting the hull was a concern for the present owner for taking out the insulation (which was styrofoam ) what are we missing in this equation. Should we continue to search for another steel boat, think seriously about redoing this one or not even be concerned. Really appreciate your collective knowledge!

In our 1983 Steel Spray 38 built by Kanter Yachts, the insulation was sprayed against all of the walls down to the waterline. We did a re-fit 2 years ago, had the hull audiogaged, and had to cut out large sections of the plating and replace it. All problems were below the waterline, due to owner neglect (me) and not taking the time to keep water out of the hull when the windows were out on the hard. The ceiling had fiberglass insulation, which we removed and installed fire resistant styrofoam, 2" thick. The foam on the sides is 4" thick. The boat was comfortable living in Gloucester, MA for 2 years in the water (we left the boat for 4 months during the height of winter, though), due to slippery snow and ice covered ramps with the 12' tides. We have a reverse cycle air/heater setup that was useless when the water was too cold, but just the propane stove was good enough for us. We now live in St Petersburg, and although we stay on the boat lots, we have a condo here... She is comfortable in pretty much any weather, due mainly to the insulation.

[Scaramanga F25]

For what you intend to do you must have insulation.

If removal of furniture and ceiling strips against hull sides and the
overhead seems too labour intensive, look for a different steel boat.

[mikecambrai]

In cold climes it is essential to have insulation in a steel boat or indeed any boat. If you do use loose insulation it should be sealed with plastic sheeting secured to the frames as you do not want any circulation around the loose fibres of the insulation.
Steel boats usually rust from the inside out due to condensation. Deckheads will be a significant problem as decks will be frosty or red hot in the sun. You just will not be able to get comfortable either hot or cold.
If you do insulate, I have always used rock wool which is flame retardant and cheaper than foam. Foam is really good but should not touch electric cables as it can have a reaction with the insulation and of course is often not fire resistant, which causes difficulty when you need to weld the hull.
If you cannot insulate a hull for use in very hot or very cold climes then buy one which you can insulate.
In wooden boats it is usual to create a void around the inside of the hull to allow ventilation of the bilges to prevent rot.

[ausnp84]

Some good and some... interesting.... comments in this post.

First up, you'll want insulation. We have 1" closed cell on our steel ketch and any areas that don't have it drip. Lots. Even when it's above freezing.

Secondly, it has to be closed cell insulation. Styrofoam isn't brilliant and neither is rockwool. Closed cell foam can be purchased in sheets, cut to size, then glued to your hull. Armaflex (closed cell) is expensive, but can be bought with appropriate fire ratings. If you need to weld the hull, you'll need access to it from the inside as well, and closed cell foam (sheets glued in) can be removed pretty easily.

Third, the current owner's thinking is flawed - they've removed the foam to keep an eye on the hull, but then made the hull inaccessible? Unless you can get to the hull to insulate it, walk away. Steel boats are a buyer's market, and there are plenty out there.

Hope that helps!

n

[lamadriver]

My steel boat has insulation but I wish it was thicker. The PO insulated from the waterline up .
When I replace the headliner insulation is going in there too.

Some one recently suggested insulating the floor and I have been looking at products I can put under eh floor boards. The suggestion of cork flooring was also brought up

Insulation may be important so so is a heat source.........

LD

[Rustic Charm]

I used Foilboard, which is a foam solid board which also acts as a fire retardent. Its instalation properties are between 1.5 - 2.8 depending on thickness. It's inexpensive and easy to install in a boat. Wont delaminate or sag.

Someone initially install 'bats' in my boat. Dont ever do this. After removing the bats and repairing / painting rust where ever they were, i had a year without insulation. Summers were like being in an oven. In winter, if the sun came out, it literally rained inside.

With just 20mm of insulation in the head liner, if its really hot outside i get cooler relief inside. In winter, after i have used a heater it warms up and becomes quite comfortable. My heaters too small though.

Foilboard is really easy to push between stringers and is cut with a simple Stanley blade or knife. I used cheap silastic to seal all the edges of where it goes in.

I intend to do my sides as i renovate, but ill increase the thickness.

Foilboard.com.au

[NSboatman]

MUST have insulation on a steel boat. No if, ands or buts. It is not optional- that is if you intend to actually inhabit it. Without it, the boat will soak you, freeze you l, and boil you- and possibly all in the same day.

No one has mentioned noise yet either. An uninsulated metal hull will drive you bonkers from the noise. Ever used an aluminum canoe? Multiply that times 1000.

Armaflex (and similar products) are excellent, but expensive, and only as good as the installation job. It is very difficult to get ANY non-sprayed insulation to sit against the hull skin with no air gap. This is important, since it is in the air gap that condensation will form, and corrosion will eventually start. This is the real benefit of spray foam. It covers everything and if done right, is bonded quite intimately with the (painted- must be properly painted) steel hull.

Of course once that intimate and complete coverage is achieved, you can no longer inspect the inside of the hull! This is the cruel dark side of spray foam. But, as I've learned so well over the last 3 years, it really isn't hard to take out quickly with a vibratory multi tool and a scraper blade; and you can buy excellent DYI urethane spray kits now at any decent hdwr store and cover a hull interior in a couple hours. I did 400 sq ft to a 2" thickness in less than 2 hours, for about $500. It's nothing to be afraid of.

Sure- if it burns it will give off toxic smoke, and a lot of it. But so will almost every other damn thing in your house, your car and your boat. Don't have a fire; and if you do, then get it out quick (always a good policy anyway) or get the hell out ASAP.

Ymmv!


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