Steel hull isolation: alternatives to foam?

[brian eiland]

Originally Posted by Wynand N

However, my last steel boat built 2008/9 I used ceramic bead insulation paint (spinoff from NASA space program) on the inside of hull and deck. Thickly applied by brush and roller and having used white color, the hull is "neat" inside. Condensation does not bother this coating and should condensation formed inside the hull still it is able to drain to the bilge sump through its drain holes in stringers etc. Magic stuff and one can still cut and weld when doing fitting out if needed and just a matter of touching up the paintwork and applied fresh ceramic stuff over area.
Best part, it does not burn and cost less than spray-on PU foam.

I see where this subject you brough up, "ceramic bead insulation paint" appears to have feel on deaf ears?? You are talking about this material, correct?

http://www.hytechsales.com/

http://www.hytechsales.com/insulatin...additives.html

[brian eiland]

Does it work?
http://www.treehugger.com/green-arch...s-it-work.html

http://www.isbu-info.org/all_about_c...insulation.htm

If I would have known about this material I've have put some in the paint they used to paint my wife's townhouse in Thailand only a few weeks ago.

[mydauphin]

Just removed some plain old Styrofoam from a friends boat. He had it in the ceiling of the front room, it apparently got wet with either a leak or condensation. It seem to hold water and rot wood around it. Some of the piece are a lot heavier than others, they are full of water. I didn't think they could hold so much water

[Nick.K]

Originally Posted by mydauphin

Some of the piece are a lot heavier than others, they are full of water. I didn't think they could hold so much water

I had a comission once to make 30 large animal hutches for a government study centre, they had to be lined with polystrene board. The board had been stored outside in the builders yard, I bought it in advance and it stood for maybe two months inside the workshop, when we came to use it I was surprised at the amount of water it contained. If you kneeled on a scrap piece your knees would be wet.
Nick.

[Wynand N]

Originally Posted by brian eiland

I see where this subject you brough up, "ceramic bead insulation paint" appears to have fell on deaf ears??

You can lead a horse to water but you cannot make it drink...

PU and more particularly, polystyrene foams were and will still be problematic in years to come. They had their purpose on ships during the Spanish Inquisition but with 21st century materials available such as ceramic bead insulation paints make them obsolete.
This link you supplied say and shows it best; http://www.isbu-info.org/all_about_c...insulation.htm

I had tested this and believe in its insulating properties and as said, condensation does not bother it, it is only about a 1 - 2mm thick and fire has little/no effect on it, infact it is non toxic.

I used ceramic bead insulation paint on my last steel boat built and if ever I would attempt to build another steel boat, this would be the insulation to use by default.

[MikeJohns]

Originally Posted by Wynand N

You can lead a horse to water but you cannot make it drink...

PU and more particularly, polystyrene foams were and will still be problematic in years to come. They had their purpose on ships during the Spanish Inquisition but with 21st century materials available such as ceramic bead insulation paints make them obsolete. .......

Not so fast Wynand ! I'll dispute that.

There has been proper independent testing of these paints and they are not what they are marketed as.
Paint cannot be considered an insulation it's just too thin a coating. Tests show that the claims are quite misleading and that they really only work as reflective coatings to reduce heat absorbtion and any light coloured coating would have a similar effect. If you painted your steel sheet with two paints of the same thickness half and half say Epoxy and Insul... ( whatever) with the same coating thickness then you would have an objective test .

Below is the result of a detailed and truly independent test of two brands of ceramic sphere insulating paints ( they are all similar) they are applied to wall gypsum board for the test note that they don't significantly alter the gypsum boards insulating factor in fact one slightly decreases it !

The claims and dodgy testing methods published by these paint manufacturers are really nothing more than scams. It might be lovely tough thick paint but it's not and never will be an insulation.

The new fire retardant polystyrenes are actually very good !

[MikeJohns]

Originally Posted by mydauphin

Just removed some plain old Styrofoam from a friends boat. He had it in the ceiling of the front room, it apparently got wet with either a leak or condensation. It seem to hold water and rot wood around it. Some of the piece are a lot heavier than others, they are full of water. I didn't think they could hold so much water

There are a myriad of grades of polystyrene. Consider Cheap floatation devices and even surf boards are made from expanded polystyrene and they don't soak up water

[Wynand N]

Originally Posted by MikeJohns

Below is the result of a detailed and truly independent test of two brands of ceramic sphere insulating paints ( they are all similar) they are applied to wall gypsum board for the test note that they don't significantly alter the gypsum boards insulating factor in fact one slightly decreases it !

I hear you Mike, but we talk about steel and not gypsum boats.

I applied to bare blasted hull & deck first an epoxy primer covered by two thick coats (+- 190micron) coal tar epoxy. Then we sprayed a thick coat of CBP as a first coat and after drying out followed by two thick coats with roller and brush.
The temperature difference inside the boat was impressively cooler compared to outside of boat.

As I mentioned before, I tested the stuff on two plates - one bare save for primer and one with CBP applied thickly on the inside and had a gas heating torch align a little distance from test pieces (approx 350mm) so both got the same heat. After a short while the primer on the bare plate start to smoke and burn away and plate scalding hot and would not even attempt to touch it. At the same time the other plate subjected to the same heat discolored to blueish tint on flame side and the inside with the CBP coating still cool to the touch with the backside of hand! Now that is what I call proof.
If it keeps heat out out of boat in summer, it can also keep heat trapped in winter.

BTW, since NASA engineered this stuff (albeit different formulas obviously, but same principle) it must be worth the effort.

[brian eiland]

Wynand, would you differentiate what you applied in the bilge areas verses what you applied to the topsides?

[Nick.K]

Originally Posted by MikeJohns

The new fire retardant polystyrenes are actually very good !

Interesting stuff for builders on a tight budget - as myself; but fire retardant doesn't neccesarly mean suitable for boat use. As far as I can see all these products are produced for the construction industry not the marine and as you point out there are many types of polystyrene and many surface treatments. You also mention one as being better - implying that the others have problems. When I google fire retardant polystyrene the results show mainly packaging material. Most fire retardant insulation board seems to be PU or phenolic.
Do you know of a source of information on which brands of polystyrene board are appropriate and the associated products such as jointing tape, adhesives and gap filling compounds. Without, it is too big an experiment to go off and buy insulation that looks good on paper but may prove to be absorbent, disintegrate with vibration or have the face foils peel off or break down. (I have seen this happen lots of times on scrap insulation outside on building sites locally)

Sorry to be challenging, you've got me interested but I can't see any way forward...

Nick.

[MikeJohns]

Originally Posted by Wynand N

I hear you Mike, but we talk about steel and not gypsum boats.

I applied to bare blasted hull & deck first an epoxy primer covered by two thick coats (+- 190micron) coal tar epoxy. Then we sprayed a thick coat of CBP as a first coat and after drying out followed by two thick coats with roller and brush.
The temperature difference inside the boat was impressively cooler compared to outside of boat.

As I mentioned before, I tested the stuff on two plates - one bare save for primer and one with CBP applied thickly on the inside and had a gas heating torch align a little distance from test pieces (approx 350mm) so both got the same heat. After a short while the primer on the bare plate start to smoke and burn away and plate scalding hot and would not even attempt to touch it. At the same time the other plate subjected to the same heat discolored to blueish tint on flame side and the inside with the CBP coating still cool to the touch with the backside of hand! Now that is what I call proof.
If it keeps heat out out of boat in summer, it can also keep heat trapped in winter.

BTW, since NASA engineered this stuff (albeit different formulas obviously, but same principle) it must be worth the effort.

Wynand
It doesn't matter what material the paint is applied to for the test. it's an objective measure of thermal conductivity. The samples in these tests are placed between a hot pad and a cold pad and the heat conduction is measured. The paint is too thin to test on its own so it's applied to a medium, in the test using something like Gypsum board is useful because you can quickly see whether it increases or decreases insulation or emmisivity. Using steel wouldn't be as good an indicator but you could, the results would just be around zero on the graph.

I looked at these paints before and found it hard to believe the claims. When I asked for hard data I found it concerning that not only were test results unavailable but the woolly experiments they were using as verification were clearly misleading.

Conductivity and emmisivity testing devices are common in labs around the world and that these paint manufacturers will not give any thermal conductivity figures when asked is the first hint something is awry.

Also the NASA paint which is apparently quite different and considerably more expensive to manufacture was developed for it's external reflective properties not it's internal insulation heat transfer. The principle is that radiated energy is reflected before it can raise the temperature of the substrate , that's not a conductive insulative property but one of reflectivity.
It's like claiming a mirror has a really high R value because a mirrored box stays cooler in the sun ( and these are the sorts of arguments used in promotional blurb for supposed "insulating paints" ).

One of the paints tested in the graph increases the emmisivity of the board it was applied to ( it actually radiates heat better ) . Consider that would also keep a surface cooler in your blowtorch test. But so would an equivalent thickness of high build clay additive epoxy.

But lets get objective: Insulation has physical properties that are easily measured, so ask the manufacturer for the thermal conductivity of the dry film and post the reply here!
Unfortunately they won't be able to give you anything very heart warming, the term "insulating paint" should be "Solar energy reflective paint"

[MikeJohns]

Originally Posted by Nick.K

Interesting stuff for builders on a tight budget - as myself; but fire retardant doesn't neccesarly mean suitable for boat use. As far as I can see all these products are produced for the construction industry not the marine and as you point out there are many types of polystyrene and many surface treatments. You also mention one as being better - implying that the others have problems. When I google fire retardant polystyrene the results show mainly packaging material. Most fire retardant insulation board seems to be PU or phenolic.
Do you know of a source of information on which brands of polystyrene board are appropriate and the associated products such as jointing tape, adhesives and gap filling compounds. Without, it is too big an experiment to go off and buy insulation that looks good on paper but may prove to be absorbent, disintegrate with vibration or have the face foils peel off or break down. (I have seen this happen lots of times on scrap insulation outside on building sites locally)

Sorry to be challenging, you've got me interested but I can't see any way forward...

Nick.

I think you are over concerned. Consider that glass wool is commonly used with the open wool side against the steel and the vapour barrier toward the inside. Even that that doesn't absorb water ! Foil backed higher quality boards are very strong durable and completely vibration proof.

Polystyrene has been used as insulation on boats since it's inception and it's problem is that it was a terrible fire hazzard but it was light and has a high insulation value for it's thickness. So it was popular and providing it never caught fire it worked very well. You'll find it in lots of older home built boats but not any craft built to flag or class. It simply didn't meet the flammability requirements. Now it does........

[pdwiley]

Originally Posted by Nick.K

Do you know of a source of information on which brands of polystyrene board are appropriate and the associated products such as jointing tape, adhesives and gap filling compounds. Without, it is too big an experiment to go off and buy insulation that looks good on paper but may prove to be absorbent, disintegrate with vibration or have the face foils peel off or break down. (I have seen this happen lots of times on scrap insulation outside on building sites locally)

Sorry to be challenging, you've got me interested but I can't see any way forward...

Nick.

I know from personal experience that the Foilboard stuff available locally won't delaminate and it doesn't appear to soak up water.

I built my house using it as insulation 10 or so years ago and there have been scraps lying in the weather for years now. I picked up some the other day & tossed them on the burn pile (I live on a 3 acre block surrounded by other rural blocks so nobody cares what I do). No delamination and no obvious signs of water absorbtion. Only an anecdotal observation, but I plan on using the stuff for my steel boat.

PDW

[MikeJohns]

I took some pictures. Here is 30mm expanded polystyrene sheet being installed.

The other picture is the fiberglass insulation commonly used. The open side sits against the hull and the vapor barrier toward the interior.

[ImaginaryNumber]

There is some fuzzy information about air gaps between insulation and hull, about dew points, and about fibrous insulation like mineral wool.

First, water vapor doesn't condense just at the dew point temperature, but also at any temperature that is colder than the dew point. That means that if the dew point temperature is reached, say, midway through the insulation, then any water vapor that happens to be between that critical midpoint of the insulation and the hull will become colder than the dew point temperature, and will condense. That means that even if you have 10" of close-cell insulation between the interior and the hull, but humid interior air can get between the insulation and the cold hull, it will condense.

Second, it doesn't particularly matter whether the insulation is bonded directly to the hull or not. What matters is whether humid air can reach an area that is cold enough to chill it below the dew point, like the cool/cold hull. If the only insulation you are using is vapor-porus, like mineral wool or open cell foam (including DIY-cans of spray foam), water vapor will diffuse through the insulation until it hits the dew point where it will condense and saturate the now minimally-useful insulation. If you have a closed-cell insulation, but have gaps around it where humid air can diffuse around it and come in contact with the cold hull, you will have condensation as well.

It is crucial that there be a well-sealed vapor barrier between the humid interior air and the cold hull. Ideally, that barrier will be as close to the interior surface as possible. If the vapor barrier is between the insulation and the hull it will be next to useless if the hull is cold enough that the dew point temperature is on the interior-side of the barrier.

Closed-cell foams that are adhered directly to the hull, like a self-adhesive sheet foam or a closed-cell spray foam, act both as an insulator and as a vapor barrier. They insure that no humid water vapor can come in contact with the cold hull.

A close-cell sheet foam that is not adhered to the hull (like homebuilder's Styrofoam) is also an effective vapor barrier -- except at its edges. To keep moist interior air from diffusing around the edges of the foam the edges must be sealed to adjacent foam panels with (ideally) a high-quality sealing tape or a caulk (which is usually inferior because the seal eventually breaks).

Some folks have mentioned intentionally providing ventilation behind the insulation. You only need to ventilate if there is moisture buildup, and there will only be moisture buildup if you have insufficient insulation and you don't have a proper vapor barrier.

If you use interior air to ventilate, with its typically higher humidity levels, you will likely create as much condensation as you remove. If you use exterior air to ventilate, depending on how dry that outside air is, you might be successful in drying out those portions of the hull above the waterline, where the hull might be relatively warm, but create even more condensation in the bilges where the hull is chilled by the cooler sea water (assuming that the sea temperature is substantially cooler than the air temperature).

In my opinion it is ideal to wrap the whole living space with a blanket of insulation, including the bilges. If you don't have bulk water leaks, internal or external, and you have adequate insulation and a tight vapor barrier, you should have dry bilges.