Deadening

[Estsound 7]

What's the difference between these, what would be the best ?

[Gala69 0]

Hi, these products are also imported in Italy, where I live, but I know none that use it.

[Estsound 7]

Kinda expensive stuff.

1) $24,80

2) $25,50

3) $29,20

[socialstealth 0]

Kinda expensive stuff.

1) $24,80

2) $25,50

3) $29,20

Seems like a generic brand.

I'd recommend RAA mat, second skin, dynamat.

I have a second skin coupon for 15% off for sale, and 24 sq ft of dynamat Xtreme for 75$ + shipping or local pickup

[///M5 2,833]

Can't tell you the difference without knowing more about them. A quick web search turned up nothing helpful.

IMO the best option running right now can be purchased from Don at SDS. You can find his products here:

http://sounddeadenershowdown.com/cgi-bin/index.cgi

[Rudeboy 152]

Can't tell you the difference without knowing more about them. A quick web search turned up nothing helpful.

IMO the best option running right now can be purchased from Don at SDS. You can find his products here:

http://sounddeadenershowdown.com/cgi-bin/index.cgi

Shipping to Estonia might be a little rough though

It's tough to figure out what those products are - they don't seem to correspond to the listings on the Standartplast Web site and the products they do list have pretty vague descriptions.

[///M5 2,833]

I looked to Don and couldn't find anything.

[RED3 0]

make sure whatever you use is butyl based and NOT asphalt based

[Rudeboy 152]

make sure whatever you use is butyl based and NOT asphalt based

I'm not disputing this advice, I just think it is important to expand on it. I used to believe that choosing "butyl" when selecting a constrained layer damper (CLD) got you most of the way there. Butyl does eliminate most of the melting and adhesive failure problems that asphalt has, but there have been butyl products that delaminated or fell off.

Basic stability issues have occupied a lot of our time over the last few years. That's a very low standard to set. An effective CLD needs to be a careful balance between the adhesive layer and the constraining layer. The constraining layer is pretty simple - it has to be rigid enough to resist deformations in the adhesive layer. That's why products with thin plastic or foil layers are no more effective than asphalt, even if they are more stable.

The adhesive question is a lot more complicated. "Butyl" is just a synthetic rubber compound that is mixed with many other components for this use. It isn't vulcanized or cured, so it's not like the hard rubber most of us think of generically as rubber - tires for example.

An effective CLD adhesive layer is viscoelastic over a wide temperature range. This means it is part way between liquid and "rubbery" or elastic. When cold, the material moves toward the elastic side of the scale and when warm, toward the liquid. Performance falls off dramatically if the adhesive is too liquid or too elastic. Everything depends on the adhesive staying in the viscoelastic range so that it can react to vibration and return to it's original position more slowly than it was deformed. In a liquid state the material just transmits vibration. In the elastic state it returns all of the energy it receives. This is why claims like: "highest rubber content" are either marketing claims that assume the customer is stupid, or worse, betray a complete misunderstanding of how these products work on the part of the seller. Other silly claims include those that tout softness and flexibility as virtues instead of cost saving measures that compromise the product's performance.

The requirements for constraining layer and adhesive characteristics are why it is so difficult to find alternative materials that work well as vibration dampers. Products designed for roofing or corrosion protection have completely different uses and are designed to serve that very different use. The odds of them performing well for our uses are slim to none.

None of this is to suggest that the products in the post that started this thread aren't very good - I have no idea. I'm really just reacting to a trend I've noticed in the past few weeks toward recommending products that I thought had been discredited long ago.