# Butyl based flashing tape work as sound deadener?



## ImK'ed (Aug 12, 2013)

Like title i can get thus quite cheap and it seems like alot of people here in uk use this? Any experiences?


----------



## Thunderplains (Sep 6, 2009)

It is only 1/2 of the equation.. Most deadening products are BR and some type of aluminum thickness.


----------



## theoldguy (Nov 17, 2009)

just because its cheap, doesnt mean it will work. This tape has been around for a long time. Dont you think if it was a good idea, everyone would be doing it by now? Many discussions on here and the internet in general about these products already. Do some searching and read all the info and experiences. Only then will you be able to make an informed decision.


----------



## TheDavel (Sep 8, 2006)

^this guy may be pretty, but he is a jerk... but makes some solid points


----------



## sinister-kustoms (Jul 22, 2009)

Speaking from experience, don't go there. Just don't.


----------



## SkizeR (Apr 19, 2011)

dont bother. also speaker from experience


----------



## cajunner (Apr 13, 2007)

it's good on leaky trailer tops, you can smash it around the seams and every thang...


but it's no Alpha Damp.


----------



## ImK'ed (Aug 12, 2013)

Ok yeh i'll stay away im looking at silent coat its enough for doors then i'll do boot another time


----------



## Alrojoca (Oct 5, 2012)

I would use it to place over rough looking areas where CLD was placed or seal some gaps or repair damaged CLD areas only.


----------



## TOOSTUBBORN2FAIL (Jan 31, 2011)

ImK'ed said:


> Like title i can get thus quite cheap and it seems like alot of people here in uk use this? Any experiences?


The butyl formulation is more important than anything else. Butyl flashing tape is not designed as a damper, so if if it does damp well, its pure luck. Out of hundreds (or possibly thousands) of butyl formulations, only a few of them actually damp vibration well. What are the chances that a product designed for sealing seams also works well for damping vibration?

Silent coat damps well, but it is also asphault/bitumen based, so it wont resist heat well.


----------



## ImK'ed (Aug 12, 2013)

Ah ok heat would that be a problem in uk where it might go 25-28 degrees celcius for a week in a year?


----------



## TOOSTUBBORN2FAIL (Jan 31, 2011)

Probably not an issue there, and it does perform well at around 25c. If you can find someone that has some, I would just check it out in person first. The batch I got smells really strongly like grease, but its possible that its only the 5mm bilayer product that smells, and the others just got packed in with it.


----------



## req (Aug 4, 2007)

guys, im going to give you a little idea of HOW buytl+aluminum CLD tiles work.

there are three things in constrained layer dampening;

mass to be dampened (sheetmetal in a car)
constraining layer (byutl rubber)
reflection dampening layer (aluminum)

basically when the mass to be dampened (hencforth sheetmetal) is vibrating, it will ring until the energy is either lost in heat, or radiated into the surrounding air as kinetik energy. this is bad for us. vibrations from the car driving along the road, from the air wooshing past the panels, from the engine turning - all these can excite the atoms in the sheetmetal and make it reverbirate.

so what do we do? we need to counter the ring with an equal but opposite force as best we can.

so, we develop a constraining layer (byutl hencforth) to bond a reflecting dampening mass (aluminum henceforth) to the sheetmetal that will respond to a vibration with an opposite vibration, canceling out the first vibration. 

an anology would be thus, if you were jumping on a trampoliene (the trampoliene being the sheetmetal, and you being the vibration) we could add a SECOND person (a reaction vibration) to the mix that will land as soon as you bounce - stopping both bounces and making you both fall down mosty likely. most of us have expierenced this.

in order to DO this, we use the first vibration impact to push the aluminum layer at a delay that coencides with its distance from the sheetmetal. this first impact causes the aluminum to vibrate 180* out of phase with the sheetmetal, hopefully causing both of their vibrations to stop dead in their tracks - or close to it. it is a passive system. so the viscosity or rubberness (however you want to describe the buyul) and its thickness are very important to get the aluminum layer to vibrate at the right phase-time to the sheet metal.

if those factors are not right - then the cancelation wont occur as best as we would like it, and the sound dampening wont work very well.

considering that the flashing tape is designed to be water\heat-resistant sealant, i wouldnt guess that the chemical composition of the byutl would be very good compared to specifically designed sound deadener.



TL-DR - do yourself a favor, and just cover 50% of the sheet metal you are concerned about vibrations with good CLD tiles.

check out Welcome to Sound Deadener Showdown | Sound Deadener Showdown - they have VERY informative explinations of their products, even if ordering them would be cost prohibitive, its worth a read through.


----------



## TOOSTUBBORN2FAIL (Jan 31, 2011)

With cld, the vast majority of the damping comes from the sheer forces created as the butyl flexes in between the sheet metal and the aluminum layer. While the aluminum layer does vibrate slightly out of phase from the sheet metal, its not where close to being out of phase enough for that effect to really play a role in how a cld material damps vibration.


----------



## ImK'ed (Aug 12, 2013)

Would people say dynamat original door kit is better than silent coat 2mm? And when doing doors do you recommend doing body panel and inner door skin ?


----------



## TOOSTUBBORN2FAIL (Jan 31, 2011)

Dynamat performs better than silent coat 2mm. Silent coat 4mm performs better than Dynamat. 

Start with the actual door skin that the speakers mount to. After that is dead enough to your liking, you can deaden the door card itself, and the outer door skin.


----------



## req (Aug 4, 2007)

TOOSTUBBORN2FAIL said:


> With cld, the vast majority of the damping comes from the sheer forces created as the butyl flexes in between the sheet metal and the aluminum layer. While the aluminum layer does vibrate slightly out of phase from the sheet metal, its not where close to being out of phase enough for that effect to really play a role in how a cld material damps vibration.


then please explain why the thickness\weight of the aluminum layer is important if the only part that matters is the flex of the byutl?

the buytl is made to flex so that the aluminum layer can act as a reverb - thats the entire point of a CONSTRAINED LAYER DAMPENING tile.

go ask don at SSD.


----------



## TOOSTUBBORN2FAIL (Jan 31, 2011)

req said:


> then please explain why the thickness\weight of the aluminum layer is important if the only part that matters is the flex of the byutl?
> 
> the buytl is made to flex so that the aluminum layer can act as a reverb - thats the entire point of a CONSTRAINED LAYER DAMPENING tile.
> 
> go ask don at SSD.


I never said the only part that mattered. I just said that the butyl is more important than anything else. Want proof?

Alphadamp, 10mil thick aluminum, 50mil thick butyl, 60mil total thickness. 
Dynamat Xtreme, 4mil thick aluminum, 63mil thick butyl, 67mil total thickness.

Both perform close, but Dynamat edges out Alphadamp consistently, even with the MUCH thinner aluminum layer. The butyl mixes that each company uses are very obviously different. 

SDS CLD Tile, 8mil thick aluminum, 72mil thick butyl, 80mil total thickness
Knu Kolossus, 4mil thick aluminum, 96mil thick butyl 100mil total thickness

Both perform close, this time SDS edges out Kolossus, but barely. Kolossus is much heavier, but its all in the butyl, not the aluminum. Butyl mixes are again, obviously different.

There are many more examples, if skim the CLD testing thread to the posted results, and this will be gone into in much further detail, when I release full results. Just waiting on a couple more products, and going through the results manually to archive the numbers to transcribe into the pdf form.

CLD is NOT a reverb system, at least not in the way you are thinking. And I have NEVER seen Don describe it as such, both in email conversations with him and many many forums posts by him. In fact, he lightly goes into this at the MSS forum. 

You can also read the paper in this thread, by an engineering student with the Navy, who for his Master's detailed the workings and how to measure the effectiveness of constrained layer dampers, for use in quieting naval vessels.
http://www.diymobileaudio.com/forum/1893222-post119.html

There's also this PDF by EAR Composites, which on page 3 goes into constrained layer damping, including diagrams.
http://www.earsc.com/pdfs/engineering/understandingdamping.pdf


----------



## captainscarlett (Mar 15, 2011)

As for flash tape, I could really see any real price saving (UK) once you tote up the area covered, against the likes of Dynamat or Second Skin. You might as well pay the nominal difference and get the proper stuff.


----------



## ImK'ed (Aug 12, 2013)

Yeh ive decided i may aswell dynamat original foor doors that where i really need it, shockingly my boot doesnt vibrate


----------

