A cape Horn vessel

No I'm just reporting others experiences! So far I have seen only unqualified, biased opinions about boat insulation coming up from you with no evidence of your claims or experience. What are you searching for, a fight, or a better insight?

I have just been talking to someone quite knowledgable about sprayfoam and who has used Amaflex. He says that you cannot put it on bare steel so you have to paint well first, it has to be stuck on, the time involved with cutting and shaping is considerable and it will tear if worked, you will always get voids over rivets and frames etc., the insulation value is not so good unless doubled sheeted, the cost is considerable, he's never seen it used in large areas because it is uneconomical, you would still need to hermically seal the hull, it is no more fire resistant and it absorbs water, see the spec.

You can save all of this time and expense with a permanent, well insulated to 50mm, professional sprayfoam job that is fire resistant, non smelling, sound proofing, structually useful, none absorbing and rapid curing so that you can go back onboard as soon as it skins over. Removal is easy and it can be scrapped off like paint to reveal bare metal, it only smokes if welded nearby and the kits are available to patch up or for small areas. No other system has all these benefits and he doesn't think you have ever done this work on a barge and so have no concept of the requirements. In other words you are just expressing a biased opinion and you really don't know what you are talking about, sorry.

 

Senseless to teach a blind the colour......................

.........seems others have a similar opinoin as your rapidly "increasing" rep. points indicate!

 

negative rep

No, many informed buddies, you are out numbered! You are making a fool of yourself with your "it's true because I said so" arguments.

Sticks and stones will break my bones but anonymous negative reputation will never hurt me! LOL

 

LOL.......................

 

Well, if you assume it was me, you are wrong as usual!

and could we stop now, it is getting childish.

 

What are the ISO standards for insulation?

 

You normally have to buy the standards to find out but I'll see if anyone knows, there might not even be any.

 

I know so little on this subject, but can refer both sides of this argument to this article published here.:http://boatdesign.net/articles/foam-core-properties/index.htm

 

More here.: http://www.marinesurveyor.com/meters.html

Quote.: "c. Nearly all core or strengthening materials have some affinity for water and will be affected by exposure or immersion, often with disastrous results." This statement may or may not refer to the foam in contention. Again, I just don't know.

 

I've seen spray foam over bare steel work well after many years. I've also seen major rust problems under spray foam which was professionally applied in perfect conditions.The lesson is, Spray foam over bare steel is an unreliable seal, and only a heavy layer of epoxy tar on the steel is a reliable way to prevent corrosion under it.
I have welded on foamed boats. I scrape it off for a couple of inches around the weld, then jam a water soaked rag against the steel and surrounding foam. Then I have a garden hose ready, and cool it as quickly as possible. With stainless welding rod, I quench it after every inch of weld is down, to stop the heat from spreading. Then I stay aboard for an hour or two to maintain fire watch, before leaving the boat.
One of my 36 footers caught fire in Frisco bay, while he was welding on the transom. It burned like gasoline , except where it was painted with cheap latex paint. There, the fire stopped cold turkey, despite the intense heat. It wasn't any fancy fire retardent paint, just the cheap stuff,. Given that it is free in recycling depots, it makes no sense not to paint the foam with cheap latex after foaming.
All I know who have not foamed their boats properly with spray foam, have regretted it. There is NO effective substitute. Any steel not spray foamed will drip like a faucet. Make sure you get every sq centimeter. Leave only the bilge clear.

 

I do know that latex paint over PU foam stops UV degradation.

 

How does UV reach foam inside, under the interior and panelling? When do you ever put spray foam out in the UV?

 

It was just an observation. You are the one who brought up latex as a flame retardant. This would just be an additional benefit where foam was exposed to UV. Who knows, you coulod have hung a UV light in the hull to combat black mold, which grows where there is no sunlight and is very bad for one's health.

 

The links you mentioned are for certain boat constructions in foam, they don't appear to be relevent to steel boat insulation used for keeping heat in when cold and keeping heat out when hot. Which one were you looking for?