I don't consider the flammability of the foam in a foam sandwich construction a big issue. It takes both heat and oxygen for combustion. This would seem to me pretty much of a non-issue in the real world. Our foams are contained in a blanket of glass saturated in epoxy, neither of which are flammable in any real sense. A fire will have to be started and sustained externally to the sandwich, and the heat from that fire will melt and then vaporize the foam ultimately, and it will vent somewhere and combust where it meets the atmosphere. It cannot combust within the sandwich as there is virtually no oxygen in the foam.
I've welded literally hundreds of gas tanks for people over the years........ Folks are terrified at the thought, particularly as I generally weld them using a torch with an open flame, and often with some gas in the tank. I inert the tanks using exhaust from a gasoline car engine idling, which does not contain any available oxygen............ You have to have both vapor and air for fire.
We live around many dangerous and combustible substances, and have few incidents with them.
H.W.
On 07/25/2018 12:28 PM, 'Peter Southwood' peter.southwood@telkomsa.net [harryproa] wrote:
Fumes from burning pvc are probably more toxic than from burning polystyrene
Cheers,
Peter
From: harryproa@yahoogroups.com.au [mailto:harryproa@yahoogroups.com.au]
Sent: 25 July 2018 18:37
To: harryproa@yahoogroups.com.au
Subject: Re: : Re: [harryproa] Wrapped Foam Plank infusion
Firstly, I feel i should say i really appreciate your imput Rick.
| On July 24, 2018 11:02:36 PM UTC, "Rick Willoughby wrote:
| The panels in the fire test were clad with aluminium commonly used in cool room construction.
Maybe. The video is entirely unsourced afaict. And the video is of the far more flammable EPS. Perhaps you know more about it. But the only cold room I ever worked on the metal panels could not fall off the insulation when it got hot. They were mechanically fastened to metal risers. But i know nothing.
Having a fire safe sheet fall off when it gets hot seems the kind of dumb that kills people.
| This link provides a paper that discusses the fire issue of insulating foams in more detail:
Afaict that 'paper' is a fire safety seminar power point and has nothing salient to the point. Yes, foamed plastic burns. Yes, people building build ings wrong do stupid, dangerous stuff with it. How is any of that on point?
Surely, we all agree that most buildings with foam insulation are not catching on fire and are fire safe.
| It is the melting and dripping of XPS then vaporisation that causes the rapid spread of fire. PVC burns more like wood with charing and does not melt and flow.
As I said, PVC is safer if you are parking your boat near flaming trashcans, i guess. But lets be clear, in any sort of fire event that is a threat to a boat, if the boat is cored in pvc, it will not survive because of the pvc core, right? PVC core does not help in a fire. While it might not drip or flow, certainly the whole rest of the boat will be a flame, which will be the noticeable problem. Or do you see a pvc cored ship standing proud and safe around its flaming peers? Epoxy burns, right?
| I have two types of XPS insulating foam at home. Both purchased within the last two years in Australia. Neither are self ex tinguishing. Both drip as they burn.
So you built a glass panel and the XPSS dripped through the glass?
| The H80 PVC foam I have here is self-extinguishing and does not melt when it burns.
So, when you lit the glass panel you built with H80 it did not burn?
| The linked paper indicates the importance of the overall building. system. Building a one-off boat using XPS is not going to be a proven system from a fire rating perspective.
Are you suggestion a PVC cored epoxy glass boat is a proven fire safe system? As opposed to the provably unsafe same boat in XPS?
Posted by: StoneTool <owly@ttc-cmc.net>
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