Has Anyone Seen an Insulated Steel Hull ?

[SabreKai]

with fibreglass batts and a moisture barrier like they do in houses?

I am in the process of gutting Sabre Dance, and I am dealing with styrofoam sheet stuck down with roofing cement. I'm not sure what I'm going to find when I chisel all that garbage out of there but I am thinking that to insulate the way a house is might be better as you can pull up individual panels, slit the sheet, pull the glass and inspect easier than foamed in place or glued foam. Once done, reseal the barrier with tuck tape and put down the panel. If the exterior is leak proof, then there should be no way for water to condense on the skin or frames this way. It seemed to work pretty damn good on my townhouse, that place was dry as a bone.

Comments anyone?

[David M]

Spraying in foam is a sure thing for keeping air with moisture from touching the steel. Duct tape and panels in something that moves may or may not work.

I have sprayed in foam in an aluminum boat which also acts as a noise barrier.

[DeepFrz]

I suppose it would be okay if you were sure that you could provide a 100% vapor barrier. Otherwise I wouldn't do it with fg bats. In other words, I wouldn't do it.

[ViribusUnitis]

How do you plan to deal with the condensation problem?

In building houses with the fiberglass batts, it's important that the vapor barrier be on the warm side, while the cold side be breathable to prevent a build up of moisture.

I know of no way to make a hull breathable.

[SabreKai]

Originally Posted by ViribusUnitis

How do you plan to deal with the condensation problem?

In building houses with the fiberglass batts, it's important that the vapor barrier be on the warm side, while the cold side be breathable to prevent a build up of moisture.

I know of no way to make a hull breathable.

Hmmm good point. I guess it will have to be spray in insulation. I'll have to rethink this some more. Right now all the battens for the paneling are recessed so the frames show through between each panel. Obviously that's not good if you want to keep the cold frames from the warm moist air.

[sdowney717]

whatever foam you use, make sure it is closed cell. The stuff you do yourself is not, example, those cans from HD or Lowes.

I found this for a closed cell foam do it yourself kit.
Is there something cheaper?
http://www.marinefoam.com/handi-foam...link_type=text

Handi Foam SR® Slow Rise Foam is an easy-to-use, multi-purpose two-part polyurethane foam. Our commercial grade kits provide economical installation of closed-cell foam for applications including buoyancy, thermal insulation, void filling and enhancing structural integrity. The hose and applicator gun system allows for use in filling blind cavities and hard to reach locations.

I think this closed cell foam is cheaper
http://www.fomofoam.com/steel_building_insulation2.htm

[NeptunesTrident]

Here is some good information. They do not recommend spray in, because it is not closed cell.

"The best choice among the foams for cut-sheet foam installation are Ensolite and Neoprene. There are several different varieties of each. The choice of insulation foam should be made on the basis of it being fireproof, mildew proof, easily glued, easy to work with, resilient, and if exposed, friendly to look at. Ensolite satisfies all these criteria. Ensolite is both better and more expensive than Neoprene. "

[hellosailor]

The roofing mastic was probably used to ensure there was no air space, no condensation, in the age before spray foaming was commonly available.

[DeepFrz]

The better boat builders that I know, Waterline and Kanter, use spray in foam insulation. Waterline say somewhere on their website that they use 3" of spray insulation.

I understand from what I have read on the internet that it is a dirty job and may be best to have professionals do it. Lots of nasty off gassing and when trimming the set foam it is very itchy. You must wear breathing apparatus and tyvek type suits taped at the collars, cuffs and neck with gloves. The hooded ones would be best.

[SabreKai]

This is why I love this forum. Thanks for the info on the DIY kits. I'll be buying some later this year. As for the mess and the outgassing I'm planning on buying some of those cheap tyvek jumpsuits and a force air breathing system. Right now I'm looking at the HB01 by Hobby Air. Pump, 40feet of air hose and a mask.

[Unicorn Dreams]

Santana was insulated with 1 1/2" thick polystyrene sheets inserted inside the paneling.
Just used a 3 to 4" dab of glue in the center of the sheet so the sheet was loose against the hull so any moisture could flow behind the insulation if necessary.

[catman2]

I owned a steel boat which had a neoprene type of insulation from the topsided to just below the water line. I lived aboard in Virginia for 3 years staying warm in the winter and cool in the summer. Remember steel boats rust from the inside out. If you spray in foam you get all the hazards mentioned before plus the inability of seeing what is happening to the hull. When you drop something in the bilge or drill a hole through the insulation and you will just to replace the interior you will be breaking the barrier protection. I found it best to leave the neoprene in place and use the extra two part topside paint when I was finished painting the topsides each month (and you will be painting the topsides) to paint my dry bilges. Spray in insulation will clog all limber holes and thus not allow moisture to flow to the bilge. Just because you don,t see the moisture dosen,t mean it is not there. Anyway good luck with your project I loved my steel cutter and traveled many thousands of miles in her.

[S/V Alchemy]

Originally Posted by SabreKai

Hmmm good point. I guess it will have to be spray in insulation. I'll have to rethink this some more. Right now all the battens for the paneling are recessed so the frames show through between each panel. Obviously that's not good if you want to keep the cold frames from the warm moist air.

SK, I can show you the pink closed-cell boards I have on my boat in the pilothouse, with a heavy foil backed insulation down to the waterline behind the cabinetry.

But you'll have to come to the boat!

[S/V Alchemy]

Originally Posted by catman2

I owned a steel boat which had a neoprene type of insulation from the topsided to just below the water line. I lived aboard in Virginia for 3 years staying warm in the winter and cool in the summer. Remember steel boats rust from the inside out. If you spray in foam you get all the hazards mentioned before plus the inability of seeing what is happening to the hull. When you drop something in the bilge or drill a hole through the insulation and you will just to replace the interior you will be breaking the barrier protection. I found it best to leave the neoprene in place and use the extra two part topside paint when I was finished painting the topsides each month (and you will be painting the topsides) to paint my dry bilges. Spray in insulation will clog all limber holes and thus not allow moisture to flow to the bilge. Just because you don,t see the moisture dosen,t mean it is not there. Anyway good luck with your project I loved my steel cutter and traveled many thousands of miles in her.

This was my experience looking at steel boats with spray in foam. It broke down, and it obviously confined and retained moisture. Take a look at the bilges of a 1980 Subrero Petit Prince I declined to pursue.



Nice boat, right? It had been a liveaboard in Mexico and they wanted $55K for it.

I brought with me an early, semi-pro Canon digital that had a tilting viewscreen. So I could poke the camera down farther than my head.



In my opinion and experience, the foam conceals and helps to extend corrosion. You can see that water has intruded and created a sort of rusty mist over all the foam. The rust came from steel where the barrier coatings/paints have failed and which are likely inaccessible.

Oh, sure, it was quiet inside...so quiet you could hear the plates thinning.

[Delfin]

I lined Delfin with 1/4" acoustical cork from Jelnik, adhered with construction adhesive, followed by 2" Coast Guard fiberglass batts. Zero condensation, warm and dry. The problem with most spray in foam is that if it catches on fire, it gives off cyanide gas. Fiberglass doesn't burn, and cork just smolders.

Insulation: QuietShip and Acoustical cork...