# Fabric/Material for inside of hull (walls)



## GraemeInCanada (Jun 17, 2008)

Hi Everybody,

I've been thinking to redo the inside of my boat and one of the things that has been bugging me is the vinyl that is on the inside of the hull which has a pock marked sort of pattern, like honeycombs in a way. Hard to explain but essentially it's very difficult to clean. Bits of dirt or mold will grow in these tiny little pockets and without a scrub brush it's hard to get in there to clean it. A cloth just goes right over it and cleans the borders (we're talking 1/8 inch by 1/8 inch indents, if not slightly smaller).

One of my thoughts was to try linoleum. The main issue I see is that it doesn't stretch or move around things too much to accommodate the odd shape of the hull. Any thoughts on that?

I'd like to get something, some kind of slightly foam backed fabric/vinyl that isn't going to hold mold or mildew. Any suggestions? Even related threads or anything, I couldn't find anything right away and thought maybe the experienced could assist.

Thanks


----------



## Faster (Sep 13, 2005)

No two-dimensional material is going to want to conform to the compound shapes of the hull without cutting or forming in some way. An exception might be some boats' vberth areas where the hull panels can be very flat coming out of the bow, at least above the waterline.

A proper 'ceiling' (which is the proper term for the inside areas of the hull you're working on) is the best way for this to be dealt with.

This thread is a good discussion of your problem.. several ideas here and some good shots of a proper 'ceiling'. (see post #13)

http://www.sailnet.com/forums/pacific-seacraft/70049-replacing-carpet-ceiling-2.html

Upholstering panels of doorskin or other thinner plywoods and fitting such panels in may be an option. Another mentioned there is hanging removable canvas panels, which can be made to include pockets for handy secure storage (a la the Laser 28).

I'd think that your catboat would look best with a traditional 'ceiling'.

Here's a page out of Bruce Bingham's delightful book 'A Sailor's Sketchbook" covering the topic.


----------



## blt2ski (May 5, 2005)

This might be an option. IE what I did to my boat.

Marty


----------



## mitiempo (Sep 19, 2008)

I was lucky not to have anything glued to my hull. There were 1/8" plywood panels covered with vinyl and attached to supports where necessary, for both the ceilings and the overhead. I have removed these and am in the process of doing what Faster showed above, but in my case with insulation behind. I don't think I have seen a more attractive easy maintenance way of covering these areas. Credit to Marty for what he did to his boat as I think vinyl is harder to get to look good. The wood strips can be about 1/4" thick and 1 1/2" wide and any wood you like - yellow cedar, red cedar, ash, fir, or whatever.

Some samples from my pic files:


----------



## GraemeInCanada (Jun 17, 2008)

Those are great ideas! Thanks everybody for the insight and ideas. I really like the idea of doing the slats, I may do that for the v berth area and head but will probably go with vinyl for the rest. As I'm doing my galley quite soon I'm keen to get this done while I have everything out.

Faster, we're not going to do the catboat with this. That has already been decided and it's pretty much going to be the ribs and deck up top and the walls etc have already been painted and trimmed up with teak and/or mahogany. All upside down at that! The Periwinkle and Stargazer Blog: Good pictures of the inside of the Periwinkle

This idea is for my boat which is just a 25 foot US Yacht fiberglass boat. Agreed on the idea for the catboat though, not mine to make unfortunately, I'm the assistant on that project. Thanks for the scan there, I'll definitely be following those instructions later on.

Marty, thanks and nice job! Very impressive. I will be taking a page out of your book for sure. Once I get into things I may have more questions for you!

I really like that look Brian, thanks for posting up some pictures. I'm starting to think that maybe the aft end and v berth could be done like that but I'd like to leave the main area lighter with a whiter vinyl with foam. I'm a bit unsure of good it would look.. maybe just the v berth and head for now. I'll have to test that with my 3D model...

What kind of foam can I use under the vinyl or slats? Obviously something that provides a bit of insulation and won't rot away. Any suggestions? Does anybody local know of a good fabric company to go to?


----------



## mitiempo (Sep 19, 2008)

Most of the manufacturer installed foam backed vinyl comes as one and is spray glued on. Over the years the foam rots and the glue gives out.
One solution is to use 1/8" plywood with vinyl glued to it after trimming to size. Easier to install and removable for inspection etc.
A few 1/2" ribs epoxied to the hull allows the panels to be attached easily. Insulation can be placed behind if desired. Closed cell foam like Ethafoam is a good choice. Ethafoam is soft, easy to work with, and available at Industrial Plastics. Any closed cell foam works but flexible foam is easier to work with.

Here are a couple of links that might help.
The Frugal Mariner: Insulating your boat 
Capt'n Pauley's Virtual Boatyard -- Projects Galore!!!: Installing Insulation in Your Boat


----------



## LarryandSusanMacDonald (Apr 3, 2005)

Thanks for the Link, Mitiempo.

I would like to stress that if you install insulation next to the hull you _must_ make sure that no air can get behind it from inside the boat. In cooler climes, when it is warm inside the boat and cold outside the boat, any air that gets next to the hull will condensate. That wetness will attract mold, mildew and fungus.

As I mentioned in the article that Mitiempo linked above, the insulation you use must be caulked in so as not to allow warm air to get behind it.

The theory is this: Warm air can hold more humidity than cold air. Outside: cold. Inside: warm. In between: getting progressively colder. Somewhere in the insulation between the inside and outside the boat is the temperature of the dew point of the air in the boat. You simply have to keep that air from getting to that layer of insulation which is low enough to condensate the air in your boat.

I feel this point can't be stressed enough because I have seen too many insulation failures because of this. Saltwater Suzi and I have lived aboard for fourteen years and spent 9 winters in the frozen north. (Gotta work.) We know many liveaboards in the north and many of them have put up with the condensation problem.

For the most part, we don't have the problem except in a few places where the sole is adjacent to the hull. Then we have the problem big time. (This winter, Suzi suggested we rename our boat "A River Runs Through It.") Haven't solved that problem yet - except by heading south 'til the butter melts.

Good luck.


----------



## Boasun (Feb 10, 2007)

The wood ceiling as shown above, can be considered a false bulkhead. It is great for ventilating hidden places on your vessel. Solid false bulkheads can cause mold & mildew problems if you don't have a means of ventilating behind it. Insulating material is wonderful if you are in the colder areas of this world.
And it should be applied accordingly to the instructions.


----------



## GraemeInCanada (Jun 17, 2008)

Those are great links and I read over them carefully last night before bed.

I plan on going with Reflectix for the outer layer and some foam on the inner layer of insulation and then the fabric on plywood. I like the idea of being able to take it off if I need to do something about the insulation.

So it's a bad idea to glue on reflectix and the foam? Just a bead of marine style (like sikaflex?) caulking around the edges then to "glue" it on? I was wondering about a contact cement kind of glue and then that way there just isn't any air behind the insulation. I would think that with caulking you would leave a pocket of air in there, no?


----------



## GraemeInCanada (Jun 17, 2008)

Almost forgot, I was reminded of a book I actually own "this old boat" from another thread and it goes over this process in great detail. I've actually read the book but completely forgot how much was in it due to the sheer amount of information in it. Not to count the other 3 books I have on the same kind of subjects.

It's always great to hear other people's opinions and thoughts though.


----------



## mitiempo (Sep 19, 2008)

I think the idea is to not let warm air from the interior to contact the hull or get behind the insulation. If the insulation is well attached every few inches and all around the edge it should work well. I am using an industrial adhesive that will work with foam and plastics from Home Depot - Dap but I forget which number.
I am using a combination of Reflectix and Ethafoam. 1" total on the hull sides of the V-berth as there are glassed in beams to that thickness. I will then cover that with plastic panels, then the wood strips. The rest of the interior will get less than 1", probably 1/2" Ethafoam and 1 layer of Reflectix.


----------



## GraemeInCanada (Jun 17, 2008)

Reading the book "this old boat", the author recommends not putting reflectix directly on the hull due to the fact that it can't reflect back the radiant heat into anything and instead says to leave a gap between the reflectix and the hull to allow the heat to radiate back into that air gap. Any thoughts on that? I'm just not sure myself.. both make sense. If there is no way to reflect back the heat then it will just absorb it and possibly keep it closer. 

With an air pocket it could invite moisture that you'll never get out.. plus how would that hot air then radiate out of the hull when it's already hotter out there? In turn it should theoretically just absorb into the reflectix anyways.. I think.


----------



## knotted (Feb 22, 2011)

There is little difference between marine insulation and house insulation, beyond which materials are most suitable for which use. (avoid marine use of blown fibreglass!  )

The 'reflectix' appears to be the same type of material that is often used to wrap hot water heaters; the material I have is white on one side, reflective on the other. It works by _reflecting infra-red radiation_ back into the warmer space. Two layers (separated by an air space to reduce conduction) will be more efficient a reflector than a single layer. Because it is a plastic film, it also functions as a _vapour barrier_ to prevent the passage of moisture towards the cold side of the insulation. The vapour barrier, of course, should _always_ be on the *warm* side of the insulation.

Foam insulation reduces heat transfer that occurs by _conduction_, by being very inefficient at passing heat through it. It is also most often vapour impermeable, it won't let water vapour pass through it.

The applicable Law of Thermodynamics states that 'heat always flows from a body that is hotter to one that is notter". Insulation simply impedes that flow! 

So foam insulation next to the hull, such as Styrofoam board (flexible, easily cut to shape, easily adhered, and 'blue dot' to be self extinguishing) _with all the joints and edges caulked tightly or tape sealed to the hull_ and covered with a layer of 'reflectix' material, again with _all the joints and edges sealed (usually taped) to the hull_ should be a belt and suspenders approach and more than adequate to prevent condensation behind the insulation layers.

Mostly the purpose of the insulation is to keep heat _inside_ the boat, although of course it also works the other way if you live in southern climes and air condition your boat. In this case, the hull acts as the vapour barrier.

Good luck with your project!

ps: just remember that all this makes the hull pretty inaccessible in a time of emergency! Wood ceiling can be ripped off in a hurry, or unscrewed if time permits!


----------

