mikealdren wrote:Has anyone tried foam filling any fibreglass cavities on an Elan or +2? The idea is that it might:
1. Improve safety in a crash
2. Reduce noise/drumming of panels
3. Reduce water leaks
Comments?
Mike.
Mike,
I can't add much to the conversation except to say that if you're an NVH engineer you know far more about the subject than I. One concern I would have with your idea of using foam is more with the type you use. The rigid foam-in-a-can used for insulating houses, when applied in a closed space can add so much pressure to the space that windows, for instance, will be impossible to open. I have personal experience with this. There is a type of foam which doesn't harden. It is this type which is recommended for cavities with no openings.
I can also recommend without cavil doing a search for "soundproofing" or "sound deadening" on
www.corvetteforum.com . There are pages of information from a very long discussion on how to improve the NVH of a Corvette C5. A consensus opinion was derived and I think it provides a textbook example of a very effective DIY solution to the problems you're addressing.
The liquid sound deadener is available at McMaster-Carr (do they have a UK branch?) and is sold under the brand eDead and found on the Elemental Designs web site. It is very heavy. Three gallons would add, I think, about 40 lbs to the car, if that is an issue for you.
There is also a type of bituthane ice and rain shield sold in the US as Peel 'n' Seal (in 6", 12", and 18" widths, I believe) which provides mass loading and, when installed in strips, raises the resonance pitch of panels.
In short, what you're thinking of doing has been done many times by high end car audio installers and Corvette owners (myself included). Now would also be a good time to address any radiant heat issues with a product called Reflectrix, which is a closed-cell foam with aluminium foil on both sides. It is easily affixed with 3M spray adhesive and reduces exhaust, engine, transmission heat very well.
Hope this helps; you get my vote of confidence to do exactly what you asked about, just watch out for foam that will expand and explode your fiberglass body!
GP