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I know there's a long thread on the Grenfell tower fire in the VP, but I just wanted to discuss the use of foam insulation on boats.

That fire and the revelation that some tower blocks are clad in insulation panels which are combustible and may not meet building regs, has prompted me to wonder about the safety of sprayfoam and perhaps solid polyurethane panels (Kingspan, Cellotex, etc) commonly used to insulate boats.

I have PhD in a plastic foam related subject, so I understand that all plastic foams are combustible (with perhaps the exception of a few less common types containing granite additives). I heard that the Grenfell tower was clad with aluminium/polyethylene (PE) foam. I'm not sure why PE was used (perhaps cost?) because most boats are now insulated with polyurethane (PU) which has better insulation properties than PE. I know some older boats are still insulated with expanded polystyrene (EPS) panels. There are also grades of fire-retardant EPS but I suspect most boats with EPS insulation use standard 1" panels.   

Anyway, fire-retardant foams, as the name suggests, simply extend time to ignition, but they will eventually ignite and combust. So how do we know that a builder or a contractor has used the correct grade of fire-rated foam? All the fire-rated expanding foam I've seen in hand-held cans are pink and don't expand quite as much as the white stuff, but I don't think I've ever seen a pink sprayfoamed boat - not that my observation necessarily means anything.

And I don't think boats insulated with rigid PU board are exempt from this discussion. After all, the Grenfell insulation panels were manufactured by Celotex.

Obviously the application of sprayfoam or rigid panels to the inside of a steel boat which is then panelled over is completely different to how a 70s tower block is exterior retro-clad, but we still have an air-gap behind the wooden panels on a boat and we still have potential sources of ignition such as 12v cables running adjacent or through the foam which can overheat.

I realise this is a can of worms and there are probably no easy answers...

Edited by blackrose
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PU foam which is generally what is used in boats carries a class one fire rating that  means that it is highly resistant to fire and does not spread flames quickly  so should be safe

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1 hour ago, blackrose said:

I just wanted to discuss the use of foam insulation on boats.

My opinion, based on no knowledge whatsoever, is that by the time a fire on a boat was hot enough to ignite the PU foam it's probably too late to matter. 

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1 hour ago, Loddon said:

PU foam which is generally what is used in boats carries a class one fire rating that  means that it is highly resistant to fire and does not spread flames quickly  so should be safe

There are lots of different grades of PU foams some of which don't meet the relevant fire rating standards and don't carry a class one fire rating. That was my point. Given the scandal that we are now seeing unfolding related to buildings, how do we know that correct grade has been used on boats? 

http://asfp.org.uk/webdocs/ASFP E-Bulletin Issue 8.pdf

 

Edited by blackrose
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4 minutes ago, WotEver said:

My opinion, based on no knowledge whatsoever, is that by the time a fire on a boat was hot enough to ignite the PU foam it's probably too late to matter. 

If the correct grade of foam has been used then that's probably correct, but if a non-fire rated grade was used then that ignition time will be dramatically reduced and it could matter.

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Well I know what mine is like because I had an exhaust welded into the engine room hatch and welding a piece of 2" pipe through 4mm steel didn't set it alight. My boat is lined with different thicknesses of plywood and I am quite happy that these would be well alight and I would be dead before the foam caught fire

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I don't know for certain, but I cut a bit off the insulation when I bought my sailaway and burned it with a lighter and compared it with normal (not pink) old foam (from spray can).  The results were very surprising, and the amount of foul smoke that came off the standard stuff was enough to convince me that any foam repairs would be ONLY fire rated foam.

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44 minutes ago, blackrose said:

There are lots of different grades of PU foams some of which don't meet the relevant fire rating standards and don't carry a class one fire rating. That was my point. Given the scandal that we are now seeing unfolding related to buildings, how do we know that correct grade has been used on boats? 

http://asfp.org.uk/webdocs/ASFP E-Bulletin Issue 8.pdf

 

Websters who did Parglena only use class 1 foam, suspect unless you are having a job done on the cheap most companies will be the same. 

Also have  had welding done with foam in place and no fire

Article above refers to fillers in cans rather than insulation.

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1 hour ago, ditchcrawler said:

Well I know what mine is like because I had an exhaust welded into the engine room hatch and welding a piece of 2" pipe through 4mm steel didn't set it alight. My boat is lined with different thicknesses of plywood and I am quite happy that these would be well alight and I would be dead before the foam caught fire

Similarly on my widebeam insulated sailaway Scouseboat (similar to the OP's) I used a gas blowlamp to make 28mm copper soldered joints adjacent (within 1") to the PU sprayfoam; each joint took a few minutes to heat up and the blowlamp just left scorch marks on the foam.  There was not even any smell or smoke which would have been associated with near-combustion. 

A boat would be burning very fiercely before that stuff ignited. 

Edited by Murflynn
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2 hours ago, Murflynn said:

Similarly on my widebeam insulated sailaway Scouseboat (similar to the OP's) I used a gas blowlamp to make 28mm copper soldered joints adjacent (within 1") to the PU sprayfoam; each joint took a few minutes to heat up and the blowlamp just left scorch marks on the foam.  There was not even any smell or smoke which would have been associated with near-combustion. 

A boat would be burning very fiercely before that stuff ignited. 

Well, I had some welding done when I was fitting out about 12 years ago and mine caught fire! The welder was on the roof welding in sort section of pipe used as a collar for my gas water heater flue and I was on the inside with a fire extinguisher and I needed to use it!

Edit: Granted that I hadn't cleared any sprayfoam away from the edge of the hole as I hadn't cut away enough lining and didn't have room, so perhaps foam against a hot welding rod is too severe a test, but it does make you think.

Edited by blackrose
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21 minutes ago, blackrose said:

It's basically the same stuff.

I use both types in building work on a regular basis. I'm a big fan of aerosol expanding foam but it is certainly not the same as two part PU foam.

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11 hours ago, sueb said:

When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. 

which demonstrates the difference between igniting in-situ foam with one exposed face in still air, and igniting small pieces of the same material onto a roaring fire where all surfaces are exposed. 

throwing dry leaves on to a bonfire would have been the same, but getting a pile of dry leaves to burn in the first place is quite a different kettle of fish.  (why do we refer to fish kettles in the 21st century?).

that is why the test procedure must be done in a prescribed manner.

Edited by Murflynn
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11 hours ago, sueb said:

When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. 

Nice one,   as if the air isn't polluted enough already, it's supposed to be very poisonous too.

 

Peter.

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42 minutes ago, Murflynn said:

which demonstrates the difference between igniting in-situ foam with one exposed face in still air, and igniting small pieces of the same material onto a roaring fire where all surfaces are exposed. 

throwing dry leaves on to a bonfire would have been the same, but getting a pile of dry leaves to burn in the first place is quite a different kettle of fish.  (why do we refer to fish kettles in the 21st century?).

that is why the test procedure must be done in a prescribed manner.

Fish kettles are available on free loan at Waitrose.

11 hours ago, sueb said:

When our boat was spray foamed I put the trimmings on a bonfire. The flames immediately kept 6' in the air. 

How long ago was that? Did you obtain any documentation from your sprayfoamer as to what heshe used? 

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Be careful using spray foam above head height, especially the cheaper DIY stuff, The excess gasses can quickly fall downwards over your face and it can be very irritating to the eyes, even when the foam itself is some distance away.  ;)

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But of the alternatives the only non combustible insulation is rockwool/mineral fibre, but this can absorb moisture and hold it in close proximity to the steel whilst still allowing oxygen from the air to also reach the steel.  So we have to choose between a possible fire risk (although I suspect fumes are worse) or sinking/collapsing due to rust. Life is just to short.

Edited by Detling
Phat funger trouble
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Maybe all the galley cupboards should be stainless steel with stainless steel work tops, the beds could easily be metal framed and lattice based, our bunks Offshore were like that. Formica wall and ceilings  cladding that just leaves lose furnishings to worry about and 20 gallons of diesel and a couple of gas bottles.

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