Return-Path: Sender: (Marvin Kaye) To: lml Date: Tue, 28 Jan 2003 13:40:19 -0500 Message-ID: X-Original-Return-Path: Received: from bean.epix.net ([199.224.64.57] verified) by logan.com (CommuniGate Pro SMTP 4.0.5) with ESMTP id 2001836 for lml@lancaironline.net; Tue, 28 Jan 2003 13:36:02 -0500 Received: from computer (bngr-199-224-70-243.ppp.bngr.epix.net [199.224.70.243]) by bean.epix.net (8.12.6/2002121801/PL) with SMTP id h0SIZxew010361 for ; Tue, 28 Jan 2003 13:36:00 -0500 (EST) From: "Gary Rodgers" X-Original-To: "Lancair List" Subject: re: better body work X-Original-Date: Tue, 28 Jan 2003 13:35:54 -0500 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001D_01C2C6D2.2E675170" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.6604 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_001D_01C2C6D2.2E675170 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit I don't want to imply that the epoxy or polyester will burst into a roaring inferno at any hint of a flame. I would expect that the prepreg/autoclave process that the main structure is made from is somewhat resistant simply due to the fact that the resin content per unit volume is quite a bit lower than what we get in a normal lay-up. The mass of the non-combustibles act as a heat soak and helps to keep the resin from reaching a high enough temperature that it doesn't 'melt' (sort of, as much as a cross-linked plastic can) as readily, at which state it will burn very readily. And it is just the resin (epoxy or polyester or vinyl ester unless it is brominated) that burns. However with sufficient heat from another source, like electrical fire, fuel etc there will be plenty of heat to make up for heat soak benefit of the non-combustible material so the resin will then contribute to the fire. Also remember that the HDT of the resin (heat deflection temperature) is probably in the 300F range or lower, (don't recall the actual numbers) so in the event of a fire that gets any part hotter than that the structural integrity has pretty much disappeared. Intumescent coating acts as a heat shield as well as creating a non-combustible surface as it is exposed to the heat source. Gary R ------=_NextPart_000_001D_01C2C6D2.2E675170 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I don't want to = imply that the=20 epoxy or polyester will burst into a roaring inferno at any hint of a=20 flame. I would expect that the prepreg/autoclave process that the = main=20 structure is made from is somewhat resistant simply due to the fact that = the=20 resin content per unit volume is quite a bit lower than what we get in a = normal=20 lay-up. The mass of the non-combustibles act as a heat soak and = helps to=20 keep the resin from reaching a high enough temperature that=20 it doesn't 'melt' (sort of, as much as a cross-linked plastic=20 can) as readily, at which state it will burn very = readily. And=20 it is just the resin (epoxy or polyester or vinyl ester unless it is=20 brominated) that burns. However with sufficient heat from = another=20 source, like electrical fire, fuel etc there will be plenty of heat to = make up=20 for heat soak benefit of the non-combustible material so the resin will = then=20 contribute to the fire.

Also remember that = the HDT of=20 the resin (heat deflection temperature) is probably in the 300F range or = lower,=20 (don't recall the actual numbers) so in the event of a fire that gets = any part=20 hotter than that the structural integrity has pretty much = disappeared. =20 Intumescent coating acts as a heat shield as well as creating a = non-combustible=20 surface as it is exposed to the heat source.

Gary=20 R

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