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<blockquote data-quote="Rudy" data-source="post: 3636986" data-attributes="member: 568035">If I&#039;m understanding you correctly and you are suggesting that liquid should go down first and then mat applied on top of that, I&#039;m going to disagree. ED endorses this order, but they have to - liquids don&#039;t stick well to plastics and eDead&#039;s facing is plastic. ED&#039;s recommendation helps them sell more of THEIR products. It isn&#039;t based on any good science.I&#039;m convinced a much stronger argument can be made for mat first, liquid on top. When liquid cures it has a relatively rough and porous surface. As you point out, adhesive bond is a critical component of vibration damping effectiveness. The butyl adhesive used by decent mats will stick much better to the non-porous surface of sheet metal, plastic or automotive paint.Constrained layer viscoelastic dampers rely on the interface between the adhesive and the constraining layer. As the substrate is deformed by vibration, sheer forces as the adhesive moves against the relatively less flexible constraining layer act as a brake against the energizing vibrations. The more rigid the constraining layer, the better this works. Practical considerations place an upper restriction on the thickness of the foil layer - you need to be able to cut it and shape it to contoured surfaces. Applying liquid over a CLVED mat reinforces the foil layers.Other factors like increased mass and differences in viscosity and elasticity between the two product types apply no matter the order of application. Using both products together is getting into the fanatic range. I&#039;ve seen benefits from doing both, but most people are going to be better off using one vibration damper type and then moving on to absorbers and barriers as needed.</blockquote>

[QUOTE="Rudy, post: 3636986, member: 568035"] If I'm understanding you correctly and you are suggesting that liquid should go down first and then mat applied on top of that, I'm going to disagree. ED endorses this order, but they have to - liquids don't stick well to plastics and eDead's facing is plastic. ED's recommendation helps them sell more of THEIR products. It isn't based on any good science. I'm convinced a much stronger argument can be made for mat first, liquid on top. When liquid cures it has a relatively rough and porous surface. As you point out, adhesive bond is a critical component of vibration damping effectiveness. The butyl adhesive used by decent mats will stick much better to the non-porous surface of sheet metal, plastic or automotive paint. Constrained layer viscoelastic dampers rely on the interface between the adhesive and the constraining layer. As the substrate is deformed by vibration, sheer forces as the adhesive moves against the relatively less flexible constraining layer act as a brake against the energizing vibrations. The more rigid the constraining layer, the better this works. Practical considerations place an upper restriction on the thickness of the foil layer - you need to be able to cut it and shape it to contoured surfaces. Applying liquid over a CLVED mat reinforces the foil layers. Other factors like increased mass and differences in viscosity and elasticity between the two product types apply no matter the order of application. Using both products together is getting into the fanatic range. I've seen benefits from doing both, but most people are going to be better off using one vibration damper type and then moving on to absorbers and barriers as needed. [/QUOTE]

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