> adder laid this down on his screen :
> > > Hi, I've been reading up on using bitumen based roofing felt
> > > for car sound insulation.
>
> > I don't think it was used for sound insulation, rathe it was
> > used as a cheap method to add bulk to a thin metal panel to
> > kill its resonance and prevent it 'drumming'.
>
> That's what it was and is used for. It must be properly glued
> on over the entire area. Often found with foam "crumb" backing
> for better damping. You find rubber mats glued to the underside
> of s/s sinks in kitchens, too, FWIW, to reduce drumming on the
> thin metal.
Brushing underseal on has the same effect too, and can be used inside car doors etc. But I wouldnt use it in the house due to fumes.
Regards, NT