Steel hull isolation: alternatives to foam?

[MarijoV]

Hi everybody, does anybody have some opinion or better yet own experience of steel hull isolation using any alternatives to PU foam spraying or PU sheets? Has anyone ever used some of the common house-building materials (styrofoam sheets, glass wool, etc.) and got away with it?

many thanks, Marijo

[Landlubber]

Marijov, I have used both the foams only, spray and stick on, never again will I use the foam, it causes more troubles than it is worth, and also fitting out nightmares where extra lines or wires are needed, it is almost impossible to get then through, and always something comes up that has been "forgotten", making removal of sections very difficult. The stick on works very well, covers nearly all places and allows removal for either inspection or alterations.

[MarijoV]

Hi Landlubber, thanks a lot for your reply... I am also afraid of the damn thing sticking as hell, which is great now, but in 20 years or at the very first change in interior (wires, pipes,...)??

I can't help thinking some of the usual house-building isolation materials could do. Imagine the yellow glass wool in rolls? If it would be covered with nylon sheeting under the ceiling, maybe it would be damp-free and all of teh condensation would drip to bilges?

I don't know... I built only a house, never a boat, so maybe I'm just plain stupid :-)

[MarijoV]

C'mon guys... so many views, and no comments except Landlubber's? I hope the question is not so dumb no one wishes to comment :-)

[Northman]

Marijov, you may find something useful in this thread:
http://www.boatdesign.net/forums/fiberglass-composite-boat-building/insulating-fiberglass-hull-24722.html.

[MarijoV]

Thanks Northman.... I actually found that thread and I'm sure going to check it out in details... BR, Marijo

[MarijoV]

Hi Northman, I saw the discussion... lot's of good advices... What about styrofoam (expanded polystiren)? It's unbelievelve cheap, easy to work with, and it does not absorb moisture like rockwoll or glasswool! It's easy to imagine it could simply be glued to the hull, cut with carpet knife when needed and easily replaced... have some experience there?

[daiquiri]

Whatever you decide to do, it is important that you avoid the formation of condensation between the insulation and the hull. So the idea of glueing it tightly against the hull is a good one, whatever insulator you decide to use.
Now about the Styrofoam (PS). It has a close-cell structure and is therefore a good moisture insulator and also a very good thermal insulator.

But it is also inflamable, burns very quickly and releases toxic fumes during combustion. It shouldn't be used at temperatures above 70 °C.
At about 95 °C it will start glassifying and it's good insulating characteristics will start deteriorating.
It also has very low chemical resistance to diesel and gas vapours. PU foams perform much better in that sense.

So bear all those thing in mind when choosing which parts of hull are suitable for insulation with PS.
Don't use it in zones with electrical wiring, those in contact with fuel vapours and in zones which could overheat for whatever reason and reach temperatures above 70 °C.

You can find a safety data sheet for Styrofoam here:
http://engineering.union.edu/~rapoffa/MER214/laboratories/lab7documents/Styrofoam%20MSDS.pdf

[MarijoV]

Daiquiri, thanks! Good advice on avoiding overheating zones... That stuff actually doesn't burn, but melts as long as there is fire close by... so, definitely some caution is needed, but I think it shouldn't be regarded as fuel for fire, or...?

It's compatible with bitumen, so it could perhaps be bedded into a bitumen/tar based glue or similar...

[daiquiri]

That stuff actually doesn't burn, but melts as long as there is fire close by... so, definitely some caution is needed, but I think it shouldn't be regarded as fuel for fire, or...?

It will burn! It will start decomposing at about 250 °C, which is what you see when you put it close to the fire.
But if it reaches a temperature of 450 °C it will start burning and feeding the fire, so it will actually become a fuel.

An open-atmosphere combustion of PS will hardly reach a temperature of 450 °C. That's why you only see it "melting".

But if a fire starts inside a closed structure, particularly if it's a metallic one (like your boat's hull), the temperature might (and I say "will") easily rise above 450 °C. Closed metallic structure acts like a reflector for heat radiation and therefore promotes a rapid temperature build-up to values way above 450 °C.

That's why a small and apparently harmless fire on a vehicle in a road tunnel quickly becomes a catastrophe - the temperatures can easily reach values above 1000+ °C during the arson (up to 1200-1300 °C). A special branch of fire engineering exists (and a lots of related research has been done lately) for this type of structures, for a good reason.

[MarijoV]

hmm... made me think! There is a local manufacturer here claiming "theirs will not burn", but I guess that's out in the open...huh!

[mydauphin]

Hi Northman, I saw the discussion... lot's of good advices... What about styrofoam (expanded polystiren)? It's unbelievelve cheap, easy to work with, and it does not absorb moisture like rockwoll or glasswool! It's easy to imagine it could simply be glued to the hull, cut with carpet knife when needed and easily replaced... have some experience there?

In my humble opinion, after many years.

Run all wiring on ceiling in duct, tubes, raceways etc... where removable roof panels give easy access.
Run plumbing in bilge, water, air, hydraulic, with removable floor sections, covers etc...
Insulation sides of hull with lots of spray in foam, can be done cheaply if you do first, There are many foams that will not catch on fire. Bond interior side panels to foam. No creaking....

Oh, I don't take manufactures fire ratings with a grain of salt. I get my propane torch and see if it burns and what gases it puts out. Your life could depend on it. I was welding on steel boat one time, a someone had put some poly foam where no one knew. The fire that happen was hard to put out, could not get close because of poisionous fumes.... Never have any white poly foam on a boat, it burns like gasoline but even more noxious....

[daiquiri]

Run all wiring on ceiling in duct, tubes, raceways etc... where removable roof panels give easy access.
Run plumbing in bilge, water, air, hydraulic, with removable floor sections, covers etc...
Good point. Yes, it's better to precise that the story about the fire is valid for Styrofoam as much as it is for any other insulating material. At such high temperatures, like those developed in closed-ambient fires, nearly any insulating material is inadequate. Well, maybe the mineral wool - but it has other unwanted characteristics, like moisture-absorption.
The fire needs to be prevented by adopting all the available measures, like the ones suggested by mydauphin. I would add a good switch pannel, a well done wiring and a correct engine-room ventilation.

[MarijoV]

great! thanks a lot for the advice... both you and daquiri have the same thoughts, although you are a bit more hostile towards poly :-).

Good idea about running everything in roof... but how do you insulate the roof then? If you stick everything there in the foam, than I might as well do it in the middle of the hull...

[mydauphin]

Good idea about running everything in roof... but how do you insulate the roof then? If you stick everything there in the foam, than I might as well do it in the middle of the hull...

You put conduits, or raceways in roof. Only small part of roof is used.
I then insulate around it with piece of non-flammable foam glue to ceiling. Remember ceiling should have structure and wiring and foam is within it.
This is time consuming but only way to go. I tried spray foam on ceiling it was a disaster.

Other point, living in South florida, we don't insulate for moisture control, cold waters, etc... We insulate for noise and radiant heat from sun. But it is very similar.

On conduits and raceways, yes it cost more money. But it will save countless hours later when you find out you need to run just one more wire. Oh, and we run a lot more wires than we need for future use.

[MarijoV]

Oh yeah, I wouldn't think about it without conduits and raceways... I built a house, and I know how easy it makes changing things with that... wonder why some people still don't use it on boats...

Looks like I won't be able to escape from foam... OK, let me hear it... what foam, PU, PE,...? How are the costs? All I get here are small DIY repair tins of foam...

Is it OK to use PU sheets? I guess I really like "sheety" stuff because teh thickness is easy to be determined as opposed to something which is sprayed on and then gets inflated some more...

[daiquiri]

I've used self-adhesive Armaflex sheets for hull and ceiling insulation of a steel boat. The workflow was really fast and the final result was very neat. So it's thumbs up from me. :)

[arctichusky]

There are better substitutes , I believe, for foam insulation. In vessels where Coast Guard regulations prohibit the use of spray foam, the use of mineral wool bats is common. The product can be purchased in dense compressed panels with a foil covering. One product available in Canada is manufactured by Roxul, the same company that makes the housing industries mineral wool. It does not absorb water, is fire proof totally, and is easy to cut. Check out www.crossroadsci.com. In the U.S. I think it is known as Navy board.
cheers, Frank

[apex1]

There are better substitutes ,
cheers, Frank

There are no better substitutes!
Armaflex is the material of choice! EVERYTHING else is just wasteing money, because you will remove it sooner or later.
Never think about mineral wool, polystyrene foam etc. Thats nice for a house not for boats.
Just my 2 cent, after 33 jears of boatbuilding.

Regards
Richard

[MarijoV]

Thanks for the inputs guys! I know of Armaflex, but I think it costs much more then foam, not to mention the housebuilding materials... I might as well use foam then...

I am afraid to use anything with fibers... it MAY NOT get soaked, but if it does, it's down with everything...

[Northman]

Richard,
how do you do insulate with Armaflex sheets around conduits for wiring? I suppose one does have to use two layers of Armaflex anyway to avoid cold spots - can one lay the conduit in a gap between two sheets in the outermost layer covered by the inner layer? With two layers of, say, 25 mm each, does then the conduit have to be foamed in to fill the gap?
For a steel hull, would you use Armaflex with a selv-adhesive side or with those needles and clips? Thanks!
Walter

There are no better substitutes!
Armaflex is the material of choice! EVERYTHING else is just waisting money, because you will remove it sooner or later.
Never think about mineral wool, polystyrene foam etc. Thats nice for a house not for boats.
Just my 2 cent, after 33 jears of boatbuilding.

Regards
Richard

[daiquiri]

With two layers of, say, 25 mm each, does then the conduit have to be foamed in to fill the gap?

Before Richard replies (and eventualy negates what I'm going to say...) relative to the practical installation, let me remember you that air is the best thermal insulator. Well, actually vacuum would be better, but it's out of competition here, for obvious reasons... ;)
So Armaflex+air+Armaflex is better than Armaflex+foam+Armaflex.
But you can also avoid the inner sheet of Armaflex. The lay-up Armaflex+air+plywood sheet (or interior lining or whatever you use to plate the boat inside) will suffice.

Example:
A hull wall section made of:
- 6 mm steel
- 25 mm Armaflex 0.041 W/(m K)
- 25 mm air
- 6 mm plywood
Gives a total conductance of 0.56 W/(sq.meter °C)

the same hull, but with this lay-up:
- 6 mm steel
- 50 mm Armaflex 0.041 W/(m K)
- 6 mm plywood
would give a conductance of 0.69 W/(sq.meter °C). That's 23% more!

Finaly, this layup:
- 6 mm steel
- 25 mm Armaflex
- 25 mm foam 0.035 W/(m K)
- 6 mm plywood
would give a conductance of 0.65 W/(sq.meter °C). That's 16% more than a solution with a layer of air.

[Northman]

Hardly! If it would be so easy, why bother with any kind of insulation in the first place? You could just keep a layer of undisturbed air between the hull and a layer of inner lining and be in the clear. But unfortunately you would get condensation on the inside of the hull. That's why people like me still figure what would be the best way to insulate ...
Or am I wrong?
Walter

Before Richard replies (and eventualy negates what I'm going to say...), remember that air is the best thermal insulator. Well, actually vacuum would be better, but it's out of competition here, for obvious reasons... ;)
So Armaflex+air+Armaflex is better than Armaflex+foam+Armaflex.
But you can also avoid the inner sheet of Armaflex. The lay-up Armaflex+air+plywood sheet (or interior lining or whatever you use to plate the boat inside) will suffice.

[MarijoV]

me again on polystirene... as it's CHEAP, are there ways to make it fire-proof or at least make it less sensitive to fire?

[daiquiri]

Northman, basically you've made the question and you gave yourself the answer. :)

The problem is that you need the insulation in order to prevent two phenomena: the water condensation and the thermal dissipation.
If you make a gap filled with air only, you have created the best practical thermal insulation. But remains the problem of water vapor condensating at the cold hull.
So you need to introduce another layer to your insulation. You have to sheet the cold wall with a material which will avoid the air (and the water vapor contained within) getting in contact with it. That's what Armaflex will do. It's closed-cell structure doesn't conduct the water vapor and it also act as a thermal barrier (though less efficient than air).

If you decide to fill it all with Armaflex or with a foam, you still have an effective insulation, but the overall thickness required is bigger - therefore it will cost you more and will steal the valuable space from your boat's interior.

So, to sum-up the story:
If you want the thinnest possible (but effective) insulation, the best thing is to let the Armaflex (or another closed-cell foam) insulate against humidity - and partially against heat dispersion. And then let the air gap prevent the biggest part of heat dispersion. An insulating air gap lets you save internal space, weight and money. Which is not a bad thing.

Hardly! If it would be so easy, why bother with any kind of insulation in the first place? You could just keep a layer of undisturbed air between the hull and a layer of inner lining and be in the clear. But unfortunately you would get condensation on the inside of the hull. That's why people like me still figure what would be the best way to insulate ...
Or am I wrong?
Walter

[apex1]

me again on polystirene... as it's CHEAP, are there ways to make it fire-proof or at least make it less sensitive to fire?

NO
just forget about it! Forget even the name of it. It has nothing in common with the marine environment. And on top of all possible scenarios my predecessors described so correct, it is a very weak and brittle material and unable to stand vibration. It just falls into pieces after a while if installed between two skins.

Armaflex must not be installed in two layers, it is very easy to get a perfect result with just one. No cold spots possible if done correctly. Although there are some reasons to install two layers. The engineroom for example is done best with one layer of Armaflex AF against condensate, covered by Armaflex HT for heat protection. Sometimes it is neccessary to install a third layer between those two for better sound insulation, thats Armasound RD.
AF is allways the first (outside) layer on hull plates! And if you go below waterline with it, you´ll see the first dry ship in your life!
A heat resistant material for cable and fuel conduits is Armaflex Protect R-90.
We use all of the above mentioned even in our wood epoxy yachts!`Cos condensate is an issue on painted epoxy surfaces as well! And mold is a serious enemy.
You can have all these foams in a tubular shape to insulate tubes and piping, they fit perfect on standard sized piping (both metric and archaic).
The application of these sheets are done best with the special goo Armaflex delivers, but on real flat surfaces you can use the self adhesive stuff as well.
Do not forget to insulate the frames with a thin (10mm) layer of Armaflex AF before you install the sheets on the hull. Usually 25mm is sufficient against condensate everything above may add to your comfort.
Never mix two sorts of foam, they destroy each other sooner or later chemically.
Yes Arma is not a bargain at the first glimpse, but removing crap and installing it then anyway is by far the more expensive way.
Till the early 90´s we used spray on PU foam as most of the world did, it was nice to see them boats burning some years later, when the usual repair welding was done (and it kept the yards busy). Sheets of PU get loose from the hull after a while, forming a perfect ambient for mold and rust. (so did the spray on foam too in some spots) Mineral wool does this for free right from the very first day.
If you can afford a yacht, you can afford armaflex, if not, size down!
No, I do´nt get a commission, I still have to beg for a living.

daiquiri
Before Richard replies (and eventualy negates what I'm going to say...)
Impressive enough, I did´nt.;)

Regards
Richard

[MarijoV]

Richard, thanks for the persuasive post :-). How do you deal (on metal hull) the instalation of Armaflex and wooden battens used for ceiling and interior elements mounting? Do you Armaflex everything and then screw the bolt on say frames through it, or do you bolt wooden elements on the bare (painted of course) hull first, and then work your Armeflex around/over it?

[apex1]

Richard, thanks for the persuasive post :-). How do you deal (on metal hull) the instalation of Armaflex and wooden battens used for ceiling and interior elements mounting? Do you Armaflex everything and then screw the bolt on say frames through it, or do you bolt wooden elements on the bare (painted of course) hull first, and then work your Armeflex around/over it?

The latter, never bolt structural elements through a foam, the bolt gets loose within some days. On interior surface the wooden batten does´nt need further insulation. If connected to the steel hull and (naturally) painted, you should apply a 10mm layer on it too.
AND I edited the post..........I allways do.
R.
R.

[daiquiri]

No, I do´nt get a commission, I still have to beg for a living.

:D :D :D
I believe the first part, the second one is a plain lie. ;)

[apex1]

:D :D :D
I believe the first part, the second one is a plain lie. ;)

I do´nt know what believe means, I´m an atheist. But begging is possible at different altitudes........................:rolleyes:

[Landlubber]

Really want to use Polystyrene foam...did you know that if you mix it with petrol you have napalm.........forget it (good though for Jewish Stocktakes)

[grzesiek1969]

Hallo!
I have made isolation in my aluminium Forna 37 with very hard roof styro foam (blue color - 50 mm) 9 years ago.. Everything is great: price, weight, easy to work and isolation.
Ok, I never check it in fire and I don`t have opinion ;))
Regards
First time here
Gregory from Poland

[MarijoV]

Landlubber, I didn't know that it was napalm :-). Good point... I should not drop my boat from any height more than 300 ft :-)!

By Jewish Stocktakes you mean of arson-insurance scams?

Gregory, thanks for the input, yours might be among the most important ones... Did you ever had any accidents or major soaking of any part of the isolation?

Do you know what was the specific weight of the styrofoam? Maybe it was the same thickness as for floors...

[apex1]

Landlubber, I didn't know that it was napalm :-). Good point... I should not drop my boat from any height more than 300 ft :-)!
By Jewish Stocktakes you mean of arson-insurance scams?
Gregory, thanks for the input, yours might be among the most important ones... Did you ever had any accidents or major soaking of any part of the isolation?
Do you know what was the specific weight of the styrofoam? Maybe it was the same thickness as for floors...

Did you read the posts replying to your question? Was´nt that clear enough? Hands off!
If the stuff is named with anything like "styro", it is crap! It is NOT water repellant! It does NOT stay in contact with the hull surface! It burns like hell and you will NOT extinguish the flames with the usual equipment once the fire had a chance to get hot enough (and it has between the panelling and the hull).
Our Polish friend will notice on top of that how nice his Alu junk burns down to the waterline in a brilliant silvery firework.

It may sound a bit harsh, but it is´nt meant like that.....................it is meant to be rude!
Why do you ask for professional advice if you do´nt like professional solutions?
You may as well have asked the national homeworker forum to get a reply that fits your preconception.
and grzesiek1969
that was a nice introduction, but steel hulls are not made from Aluminium and opinions are not asked if one is looking for advice! That you feel comfortable with that stuff does´nt mean anything.

Was that clear enough now?

And YES i am pis..ed, `cos sometimes we are wasteing our time drilling big holes, where just exploring the nose by finger was the solution.

Go for Gregory´s crap it is cheap and fits your needs.

Regards
Richard

[MarijoV]

wow, you are really pissed Richard!

I think it's great to have a dozen of different opinions... only then, if I see that say 10 out of 12 are thinking the same, I can get an idea what's worth and what's not... Using styro might really be very dangerous and an idea I am dropping, but I am glad Gregory actually did it and lived the whole 9 years after that to tell...

[mydauphin]

All those that want to try styrofoam- do this. Get a block, light a match, throw match on block. Stand back. Then try same with regular real insulation notice the difference.

[apex1]

wow, you are really pissed Richard!

I think it's great to have a dozen of different opinions... only then, if I see that say 10 out of 12 are thinking the same, I can get an idea what's worth and what's not... Using styro might really be very dangerous and an idea I am dropping, but I am glad Gregory actually did it and lived the whole 9 years after that to tell...

Yes I am.
First one should divide advice and opinions. Second one should look after the value of a statement. If ten amateurs tell you they stay alive and feel fine with crap and three pro´s tell you to leave it, make a clever decision.

[MarijoV]

You are absolutely right, but you have to have one thing on your mind. I am an AMATEUR (even less...) and new to this site, so I do not know at all who YOU are and can not tell from your nick the level of your expertise. If you get offended by someone not immidiately saying Jawohl!, that's limiting the chances someone might actually take your advice, but of course that's not your problem, since you are volunteering your advice anyway...

If say Dudley Dix had made a post saying "Err, Marijo, I understand were you are aiming in terms of cost-containment, but look, its going to make a saving of only 30% compared to PU foam, and I know of 2 yacht that burned down with that crap in mid 80s..." I would cut the discussion. Here Gregory was saying that it works for him for 9 years, and a bunch of guys were just screaming "crap, crap, crap...!"

To sum it all up, thanks to you apex1 and a lot of others who think similar to you, I got convinced that styro is not a very good idea, because of increased risk of fire-fueling in the case of fire. I will not use it.

[peter radclyffe]

Hi everybody, does anybody have some opinion or better yet own experience of steel hull isolation using any alternatives to PU foam spraying or PU sheets? Has anyone ever used some of the common house-building materials (styrofoam sheets, glass wool, etc.) and got away with it?

many thanks, Marijo

can you get cork sheets, & flame retardant paint, how about astroturf

[whoosh]

Korex, is what I use, same stuff they make lifejackets of, even feels warm nice to work with
see here
http://www.forman.co.nz/products_list.php?catid=31

understand richard, I stopped contributing mainly because amateurs ask over and over, til they get the answer they want to hear---- opened this thread in case there was a better product For artic fishing ships i have seen 8 inches of some grey home type insulation, I have no idea what it was but would be fireretardant for sure(insurance and cert bureau rules)
there are no shortcuts in boatbuilding, sure there are different approaches and(right) ways, but no shortcuts
cheers

[apex1]

can you get cork sheets, & flame retardant paint, how about astroturf

Thanks for the hint Peter.
It may sound crazy but cork is a very good choice, but unfortunately very expensive if you compare the same technical properties with armaflex. If you add heat resistant paint (and you should), it is out of comparison. Although it does´nt burn as easy as one would think. But if the fire retardant paint gets scratched and cork sucks moisture it is a good fertile soil for mold and mildew. Leave it.
The same for astroturf, it has not a single property needed in this application, and is expensive. Egg carton is cheap, but has one or the other disadvantage too.
Stu, the vinyl foam is not bad, but not that much different in price too, and Arma is much better.
Regards
Richard

[peter radclyffe]

Thanks for the hint Peter.
It may sound crazy but cork is a very good choice, but unfortunately very expensive if you compare the same technical properties with armaflex. If you add heat resistant paint (and you should), it is out of comparison. Although it does´nt burn as easy as one would think. But if the fire retardant paint gets scratched and cork sucks moisture it is a good fertile soil for mold and mildew. Leave it.
The same for astroturf, it has not a single property needed in this application, and is expensive. Egg carton is cheap, but has one or the other disadvantage too.
Stu, the vinyl foam is not bad, but not that much different in price too, and Arma is much better.
Regards
Richard
yes, arma sounds much better, the cost & rot of cork are always a problem, its better if its a synthetic, which by design are usually flame retardant

[peter radclyffe]

You are absolutely right, but you have to have one thing on your mind. I am an AMATEUR (even less...) and new to this site, so I do not know at all who YOU are and can not tell from your nick the level of your expertise. If you get offended by someone not immidiately saying Jawohl!, that's limiting the chances someone might actually take your advice, but of course that's not your problem, since you are volunteering your advice anyway...

If say Dudley Dix had made a post saying "Err, Marijo, I understand were you are aiming in terms of cost-containment, but look, its going to make a saving of only 30% compared to PU foam, and I know of 2 yacht that burned down with that crap in mid 80s..." I would cut the discussion. Here Gregory was saying that it works for him for 9 years, and a bunch of guys were just screaming "crap, crap, crap...!"

To sum it all up, thanks to you apex1 and a lot of others who think similar to you, I got convinced that styro is not a very good idea, because of increased risk of fire-fueling in the case of fire. I will not use it.

dont demean yourself, the father of yacht design, dixon kemp, was a self proclaimed amateur

[MarijoV]

Peter - thanks a lot :-)

Cheers, Marijo

[TeddyDiver]

I've so far being familiar with Armaflex only in housebuilding projects, as tube isolation, and wondering what are the suitable Armaflex products for hull insulation. AP looks about right but local dealer doesn't have that, instead they have NH :confused:

[marshmat]

Now, now, boys, don't be so hard on poor old polystyrene foam.
Yes, it burns furiously and with a toxic, black smoke. Yes, it deteriorates and makes a mess. Yes, it breaks off from whatever you glue it to. Yes, most glues, solvents and chemicals will eat it. No, it really does not belong on board a boat.

But.... it makes wonderful billets to hold up a floating dock :)

[apex1]

I've so far being familiar with Armaflex only in housebuilding projects, as tube isolation, and wondering what are the suitable Armaflex products for hull insulation. AP looks about right but local dealer doesn't have that, instead they have NH :confused:

Not AP Teddy, AF is the stuff to prevent condense water, it is the "basic" metal hull insulation material.
NH is the better quality used as a fire retardant insulation. If its the only type of Armaflex available at your place, you can install it instead of AF but its a bit more costly.

Matt, please forgive, I´ve forgotten that purpose of styrofoam! It is perfect for a floating jetty (as long as you prevent it from UV rays).
I would like to go deeper into it, but have to deliver a yacht and so, I´m on a shake down and delivery run for some 14 days (if all goes right). My first 36 meter format, so the "Patron" is doing the job himself.

Regards
Richard

[TeddyDiver]

Thanks
Armacell link for AF properties seems to be broken.. And forgot to mention, I'm insulating wood/epoxy hull, so corrosion isn not an issue..

Styrofoam.. we made some styro-dummie-owls for crow hunting when we were kids.. a lot of fun

[peter radclyffe]

Thanks
Armacell link for AF properties seems to be broken.. And forgot to mention, I'm insulating wood/epoxy hull, so corrosion isn not an issue..

Styrofoam.. we made some styro-dummie-owls for crow hunting when we were kids.. a lot of fun
if weight is not a problem why not use wood, no seriously

[TeddyDiver]

if weight is not a problem why not use wood, no seriously

:D Are you talking about hull insulation or decoy owls?

[peter radclyffe]

how many guesses you want

[apex1]

Thanks
Armacell link for AF properties seems to be broken.. And forgot to mention, I'm insulating wood/epoxy hull, so corrosion isn not an issue..

Styrofoam.. we made some styro-dummie-owls for crow hunting when we were kids.. a lot of fun

Here we are Teddy:

http://www.armacell.com/www/armacell/armacell.nsf/ansHTMLSeitenLookUp/INT_Frame?OpenDocument&Link=/www/armacell/INETFAQ.nsf/ID/0441485EFA77484580256FDC00624346?OpenDocument

and, btw. as mentioned before, I produce in wood / Ep only and use Armaflex. Condensate and the resulting mold are the issue, not corrosion.

Regards
Richard

[TeddyDiver]

how many guesses you want

Two? :p

[Brent Swain]

I've tried most of them over the last 33 years of living aboard steel boats, mostly in BC waters. No matter how I tried to get a good vapour barrier , both styrofoam and fibreglas wool got soaking wet behind it and little bubbles started to appear in the paint. Fibreglas wool got sopping wet by the end of winter.
Friends tried sheet styrofoam and found it more expensive and far more labour intensive than if they had simply had the whole thing sprayfoamd, and it was nowhere near as good a result.
The use of the vaccum filled ceramic insulating beads added to paint, drasticaly reduces condensation, but doesn't eliminate it. Cork is organic and goes a beautiful moldy green by the end of winter, altho grinding it up and mixing it with paint may work to some extent. So far I have found no reasonable alternative to urethane sprayfoam, the best money one can spend on a steel boat. I have lived in a steel boat year round in mostly cold climes for 33 years and have no complaints about sprayfoam. My boat is warm and dusty dry in all conditions.
Electrical conduits should be installed before spray foaming . This will solve the running of electrical wires. For welding I scrape out the foam for three inches around the weld , then put wet rags over the entire area, weld, quench, epoxy, then spray the foam back in with spray cans. No problem.
Make sure you have several coats of epoxy tar on the steel, before sprayfoaming. Spray foam does little to protect the steel. Cheap latex paint over the foam drastically improves fire restance. You can get it free at recycling centres. Make sure you have at least a half inch of foam over every sq inch of steel, or it will drip condensation like a leaky faucet.
Brent