Sound Deadening
02-11-2009, 08:37 PM
#41
Yankee
Join Date: Oct 2003
Posts: 3,599
-adhesives have issues in the cold (as in they just dont like to stick if they aren't already stuck)
-damping sheets themselves loose their ability to perform as a damper (the cold limiting the viscoelastic properties of the butyl thus it doesn't damp (as measured by ASTM 756) worth a darn when cold).
-The ability to perform as a transmission loss product (TL) (as measured by ASTM E90) stopping noise from entering or leaving the vehicle or what you call deadening will be relatively unaffected except the sheet metals resonant frequency will go up.
in the heat you get essentially the opposite:
-adhesives work well
-the damping works well hot till it gets too hot and the rubber goes to a runny gelatin and then it could slump
-the transmission loss should again be relatively unaffected by heat
the variables: if the mat isn't well adhered (properly installed) it will suck **** as a damping product BUT it will once again perform fine as a TL as long as it completely covers the skin of the metal like a blanket... but blankets dont stick to walls well do they you really have to install it correctly
for a damping product to be a good TL product it needs to cover most if not all the resonating area of the cars skin. To perform well as a damping material it doesn't need to cover much more than 50% if it is a thick or massive (heavy) product like Dynamat or Second skin. The light weight products WILL HAVE light weight performance as a damping product this is law
-damping sheets themselves loose their ability to perform as a damper (the cold limiting the viscoelastic properties of the butyl thus it doesn't damp (as measured by ASTM 756) worth a darn when cold).
-The ability to perform as a transmission loss product (TL) (as measured by ASTM E90) stopping noise from entering or leaving the vehicle or what you call deadening will be relatively unaffected except the sheet metals resonant frequency will go up.
in the heat you get essentially the opposite:
-adhesives work well
-the damping works well hot till it gets too hot and the rubber goes to a runny gelatin and then it could slump
-the transmission loss should again be relatively unaffected by heat
the variables: if the mat isn't well adhered (properly installed) it will suck **** as a damping product BUT it will once again perform fine as a TL as long as it completely covers the skin of the metal like a blanket... but blankets dont stick to walls well do they you really have to install it correctly
for a damping product to be a good TL product it needs to cover most if not all the resonating area of the cars skin. To perform well as a damping material it doesn't need to cover much more than 50% if it is a thick or massive (heavy) product like Dynamat or Second skin. The light weight products WILL HAVE light weight performance as a damping product this is law
Last edited by JohnVroom; 02-11-2009 at 08:41 PM. Reason: why is Istanbul called Istanbul not Constantinople? Its nobodies business but the Turks
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