any ideas how well it copes with heat?
ive got to use something on the bottom of a bonnet, to make it sound better when its shut and cut some of the noise down coming out of it, would sludge be ok or does it need to be spectrum firewall?
which do you have in nice small quantites mike?;)

Damplifier Pro has a heat tolerance over 260 degrees

Im guessing the sludge is the same

they do a version of the sludge with ceramic beads in it is designed for bulkhead/high temp applications

Firewall has much higher temperature rating than sludge or spectrum and is perfect for engine bay use. However the ceramic composition also makes it a better sound deadening liquid and is therefore Second Skins ultimate liquid damper regardless of application.

If you simply want to sound proof the bonnet, then you need Motormat:
http://www.caraudiodirect.co.uk/product_info.php?products_id=4858

Remember regular Damplifier can also tolerate heat as high as 500 deg F. Therefore if you scrub clean the bonnet so the damplifier sticks 100% it won't fall off and this will do a great "budget" job too....

Good info here guys!

Sludge does have some of the same ceramic spheres that are in Firewall, but not nearly the same amount.
Because Sludge is a curing polymer it will never return to its previous state. Like asphalt for example.. or water even. Because these products are temperature dependant and non curing they can liquefy and solidify countless times. Sludge on the other hand can not. None of our liquids can. It is kind of like concrete. Once it cures you can never go back.
This is good for high heat areas like the firewall of the car and any area above a muffler or.. exhaust system. These products will never fail in those settings, however if your goal is to not only reduce noise, but heat as well, then our product Second Skin Firewall is ideal. The ceramic content is extremely high and as such will dissipate the heat much better than Sludge will.

As far as the issue of Firewall being the best product we offer, it is…. and it is not...
For structure borne noise; vibrations, good old regular Spectrum is our best product. For airborne sound waves, Firewall is our best. This is because the ceramic spheres are nano-scopic vacuums which airborne sound has a difficult time passing though. The ceramic is so thick it creates a barrier. It does have some limitations but as it will do a much better job with noise that with vibrations.

This is why a combination of products is idea. Our most popular combo is a layer or 2 of Damplifier followed by 2-3 mm. of Firewall.

That is a very difficult arrangement to beat.

Hope this helps

ANT