What kind of foam?

[Rudy 10+ year member]

Thats probably why the asphalt based deadeners dont work so well. The asphalt doesnt deform as easily as butyl.

Correct - asphalt isn't viscoelastic.

 

[whitedragon551 5,000+ posts]

Correct - asphalt isn't viscoelastic.

Would it also be safe to say a deadener with more butyl would work better than one with less provided the aluminum is the same thickness?

 

[sacsking916 5,000+ posts]

i learn more and more daily

 

[Rudy 10+ year member]

Would it also be safe to say a deadener with more butyl would work better than one with less provided the aluminum is the same thickness?

Not really - either in terms of thickness or quantity of butyl in the adhesive. The formulation of the adhesive is key. Just because the base is butyl doesn't mean it will be a good vibration damper. Roofing materials with butyl adhesive are poor vibration dampers. Part of this is because they either have a thin foil, intended to block UV only, or no foil at all. The other reason is that the adhesive is designed to be weatherproof at the lowest possible - which makes sense.

Durability is very important for this application. It's possible to create a pretty effective vibration damper that won't hold up over time, especially under the conditions it will see in a vehicle. You'll see claims that Brand X is better than Brand Y because both use adhesives with a butyl base and Brand X is cheaper. The reality is that this is a very competitive market. Brand X almost always has an inferior and much less expensive to produce adhesive. Ironically, brand X is usually marked up considerably more than Brand Y - just like the old days when the relatively higher price of butyl based products allowed those selling asphalt based products to charge more for them. It's a crazy business.

 

[subzero 5,000+ posts]

deaden the doors, reduces vibration and un wanted resonance. Foam help smooth out the peaks and req response. Sealing it off helps countain sound waves and gives you an enclosure effect. and if you must, you can actually build and enclosure into the door..