Does GRP burn?

[PabloPicasso]

If a typical GRP boat has a fire on board, how vulnerable is the hull? Does GRP readily catch fire, have some resistance, or is it hard to set alight. I realise in a fire that there will be other issues, fumes, fuel and gas, melting through hulls etc.

 

[superheat6k]

If a typical GRP boat has a fire on board, how vulnerable is the hull? Does GRP readily catch fire, have some resistance, or is it hard to set alight. I realise in a fire that there will be other issues, fumes, fuel and gas, melting through hulls etc.

Although it can be hard to get going, not only will it burn, not much, apart from sinking in the water it floats in, will put it out ! That's why when GRP boats do catch alight they will burn to the waterline.

 

[TQA]

!2 boats destroyed in this fire. Nost if not all were fg.

http://adagiocruising.blogspot.com/2014_02_01_archive.html

 

[West Coast]

Simple answer is yes, GRP resin burns. Ease and rate of burn will depend on many factors, eg type of resin, if the laminate is resin rich, but main one is if any fire retardant additives are present. These are included in mainstream resins such as Isopthalic or orthopthalic polyester, vinyl ester or epoxies if fire retardant is required. The structural GRP components we use in our business are generally fire retardant, reducing ignitability, limiting surface spread of flame and making them self extinguishing. But these are limited capabilities, in a sustained fire situation, these additives will become exhausted and the GRP resin will burn. Problem is that many of these additives are halogen based, so when burning occurs, the toxic fumes can be serious. More modern additives are available which are non halogen based.

The one GRP resin which is different here is phenolic, it has inherently better fire retardant properties to other resins. But for a number of reasons, it is not really suitable for boat building.

I would guess that most GRP boats do not have fire retardant additives, mostly due to cost.

 

[sailorman]

If a typical GRP boat has a fire on board, how vulnerable is the hull? Does GRP readily catch fire, have some resistance, or is it hard to set alight. I realise in a fire that there will be other issues, fumes, fuel and gas, melting through hulls etc.

polyester resin has been known to burn quite well

 

[Lakesailor]

I got some grp flat sheet with a bathroom tile relief for use in showers. I had some left over and thought I would use it for a surround to a cooker.
being diligent I tested it with a gas blowtorch. With the torch 6" from the surface it took 20 seconds to scorch and a further 10 seconds to actually catch fire.