Steel hull isolation: alternatives to foam?

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)

 

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

 

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

 

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...

 

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.

 

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.

 

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.

 

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

 

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

 

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

 

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

 

Peter - thanks a lot

Cheers, Marijo

 

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