Steel hull isolation: alternatives to foam?

Thanks, Richard
I'm slightly into the panic mode about the expense that Armaflex is going to represent for what we want but truly don't want to compromise about it. The trouble is that there is a monopole on the distribution of the stuff over here and that drives me crazy that I cant shop ...arrgg... I feel cornered by sales man.
I had priced it in 2007 when I budgeted the cost of building the boat and it turns out that in 3 years the prices have gone up over 60%. Does that sound right? Or am I facing a local opportunity increase?

M

 

I´ll try to check that Murielle. But I am still sailing, may take a bit.

Richard
edited:
Modern times.......
thanks GSM!

Per one mm thickness, the m² is roughly 1€ fob.

 

Did a quick check (well, ordered it),

Isover Ultimate is about 5€ m² at 100mm thickness.

Armaflex AF about 10€ at 10mm

I would recommend to execute the hull insulation against condensate in Armaflex 10 or 12,5 mm and the additional heat insulation around your living space and above waterline (from 30cm below in fact) in mineral wool. On top of that.

Regards
Richard

 

Great. A few conversions later (I'm in imperial world here) and seems like the prices I've got are not too outrageous. About 8% more for me, shipped. Makes me feel better...but certainly not richer

I'm quoted on the AP, I believe that AP is the north American equivalent of AF. AP is whats available here and when compared specs they seam fairly similar (would it be the QC standards that would differ to match requirements for either side of the pond?). Dashew's boat is used as example by armaflex with AP.
I haven't dared getting a quote on NH but might . What do European standards say about use of AF vs NH, do they actually dig so far in details or is AF good enough to make everyone happy?

Murielle

 

AF is EU standard, AP is ASTMA standard, same stuff!

What s NH, the fire retardent foam. Used in engine rooms mainly. Don´t know what the EU Standards say, but sure there is no comparison. Personally I use the NH on top of a thin AF sheet in engine rooms only.

 

Yep, it's the halogen-free all bells and whistle stuff. http://www.armacell.com/www/armacell/INETFAQ.nsf/vFrame1/3BFA1A697C8EC9A4802570840039E57C
Turns out I can't get it easily anyway, so be it.

 

Do you need a price for NH too? I have no access now, yards closed! Bayram, all nuts here for several days.

 

No need, I couldn't order easily NH anyway. I get tired of jumping hoops so I'll go with the easily (somewhat) available AP. Also debating on your "mixed materials" idea (armaflex/ultimate). Thanks.

Murielle

 

Richard,
not to argue, just curious. Won't the mineral wool sooner or later get soaked, even if the Armaflex takes care of the condensate? You were quite critical to mineral wool earlier and pointed rightly out that it captures humidity fast, but that it takes forever and a day to release it. There is always plenty of water inside a boat from cooking, oil clothes and whatnot.
Regards
Walter

 

Right Walter,

if the mineral wool would be the only material I would not recommend it as was made clear in previous posts.
But tha Armaflex stops the main source of water ingress, condensate. The remaining humidity is there as gas, not water. And that will leave the mineral wool as easy as it got in.
The material in question here, is not the simple and cheap stuff commonly found at the hardware stores btw. This is already a magnitude better, and it could be a sensible choice in mild climate like the Mediterranean Sea. Unfortunately it is not as good on condensate prevention as Armaflex and insufficient in higher latitudes.

Regards
Richard

 

Richard,
I hope you got your Internet trouble fixed in Turkey? Thanks for the info,

It would then be better not to use this Isover mat with an aluminium facing, but with an open surface?

Do you mean that it's not sufficient in colder climate alone or in combination with the Armaflex? I am pretty much in the same climate as Murielle; either cold or lousy cold.

Regards
Walter

Murielle,
please keep us posted how you and Mark eventually decide. I am really interested to hear about your choice!

 

In cold climate like yours (and mine) mineral wool does not prevent condensate build up. It is not in contact with the hull due to the fibrous consistency.
If you have solved the prob. with a layer of Armaflex you can of course improve the values by adding a sheet of Isover on top.

Regards
Richard

 

The Armaflex quest is on going...

As it is I'm pretty much sure we will be going with Armaflex and no mineral wool.* I think combining two product solution is a viable one and I did investigate it but, punching in the numbers it turns out not to provide enough economical advantage (for my situation) to split the insulation system in two, condensation barrier and heat barrier. It certainly would be a consideration for our boat if it would be destined to warmer climates or to only be used in summer but we lived on board our previous boat in sub -30C and could see this non sens happen again.
According to armacell's information sheet, for a proper condensation barrier, most sever conditions (-18C hull temperature / 32C interior / 80% RH) require 2" of armaflex. Yes, I agree this is for pretty extreme conditions but believe it or not we have experienced it. The boat frozen hard in the ice, minus thirty outside, the wind howling but more than toasty in the boat...warm memories...but back to my insulation... For condensation alone we are bond to 2" of insulation. Our rib depth is 4" on the hull, 3" under the deck. We want our lining to press against the insulation, no air gap; the reason is simply to eliminate void spaces which could accommodate unwanted creatures, hence bugs and vermin. We considered boxing in our frames to reduce the lost space and amount of insulation needed to fill the gap but realized that the gain was minimal for the increased labor. In fact, with wintering in cold climates in mind, 4 in of insulation is not as crazy as it may sound (yet way overboard for most boats) and would be at our advantage. So I ran numbers/dollars for 2" of Armaflex and 2" of Ultimate (mineral wool) and the cost wasn't much less than 4" of Armaflex, certainly not less enough to counter the cons of dealing with two different materials. In fact, as the pricing of the insulation is in function of the amount purchased (buy more and price per square foot goes down), buying smaller quantities of each material drives prices up compared to buying more of a unique one. I would have to be building much bigger or many more vessels to make it worth while to deal with two different insulation material.

http://www.armacell.com/www/armacell/ACwwwAttach.nsf/ansFiles/AP%20Armaflex%20Sheet%20&%20Roll.pdf/$File/AP%20Armaflex%20Sheet%20&%20Roll.pdf

My Armaflex shopping has been a whole venture of it's own...not quite strait forward. Armacell's market target is obviously more into the big industry than nagging young women. I am actually not that bad of client (don't like back and forth dealing games), but I've hit some sales practice which are not quite my piece of cake. Lets just put it like this, quotes have range from $15000 (no wonder some people get the idea it's outrageously expensive) down to $4000 for the same job. If a distributor doesn't want my business, that is fine by me but they can just say so, not waste my time. Anyway, I finally found shoe that fits my foot and placed my order for Armaflex AP. I found a dealer in the US which has been a charm to deal with. I'll wait to have all transactions completed before saying more (don't want to jinx it) but can say already that trying to deal with local distributors (Canada) has not been a good experience.

 

Hi Murielle,

thats good news!
I feared you would end up near the upper end of the price scale, or even north of it, when going to such thickness.

You are aware that you have to cover the frames before you put the thick sheets on the hull plates? It is NOT necessary to insulate the frames as thick! Some 5mm will do.

Where do I collect my commision?

 

No worry about covering up the frames. We are well aware of it and have the job planned to eliminate all heat bridges. No heat sink between cold and hot surfaces shall be left bare. I'm actually not only going to cover frames but also will not have any fasteners bridging cold to hot.

Hopefully commission will be honored sometime on your side of the pond. If ever you see our boat sailing by make sure to call us over and we could share dinner, drinks and good stories.

Murielle