[DeTomaso] Sound Deadener - Dynamat Xtreme vs Peel & Seal
George P Dausch IV
gpd4 at juno.com
Thu Jul 14 10:47:07 EDT 2011
As some of you know, one of my tenants is a company called Sound Deadener
Showdown. He started out testing sound attenuating materials
independently, eventually becoming a business. Since we do a lot of this
work both in my body shop and in the bus conversion business, it is a
subject that I follow. When this email was posted a few days ago, I sent
it to him asking his opinion. Fwiw, below is what he replied.
GPD4
--------- Forwarded message ----------
From: Don Sambrook - Sound Deadener Showdown
<don at sounddeadenershowdown.com>
To: George P Dausch IV <gpd4 at juno.com>
Date: Wed, 13 Jul 2011 09:34:04 -0400
Subject: Re: Fw: Re: [DeTomaso] Sound Deadener - Dynamat Xtreme vs Peel &
Seal
Message-ID: <4E1D9ECC.3000605 at sounddeadenershowdown.com>
References: <20110713.085002.5684.0.gpd4 at juno.com>
George,
It's certainly interesting but I can say without hesitation that the
tester has come to the wrong conclusion. Flame through and spread rate
might be relevant if the goal was to protect the vehicle from fire - in
which case neither would be a good choice. Let's assume that the
intended purpose is vibration damping or Dynamat Xtreme wouldn't be
considered in the first place.
This argument has been going on for many years. It really comes down to
the two materials looking vaguely similar and people concluding from
this that they can serve the same purpose. The visual similarity doesn't
go further than - black on wide side, shiny on the other.
The key point is that peel & seal uses an asphalt adhesive. Vibration
dampers that look like this are called Constrained Layer Dampers or
CLDs. For them to function, the adhesive needs to be viscoelastic and
the foil needs to be strong enough to resist the adhesive after it is
deformed by vibration and returns to stasis. Dynamat Xtreme has a 4 mil
foil that serves this purpose well. P&S uses a very thin foil/plastic
laminate that doesn't even come close. Critically, asphalt is not
viscoelastic.
The argument used to be around the durability of asphalt. Roofing
products like P&S use an asphalt/rubber compound. The rubber is added to
increase the heat tolerance of the asphalt. When fresh, the adhesive
will melt around 185°F. The pro-asphalt side argued that 185°F couldn't
be reached inside a vehicle, based on measurements of the airspace and
not the sheet metal where these products live. It was assumed that
people who used asphalt and had it melt or fall off had not installed it
properly. The reality is that the rubber used to stabilize the asphalt
deteriorates over time. As it degrades, the heat tolerance of the
compound falls. It was very common to see failures during the 2nd or 3rd
summer after installation.
The durability question became moot when we started testing vibration
damping performance. Asphalt is a TERRIBLE vibration damper. In testing
I've done, it takes 10 times as much asphalt material to approach the
performance of a purpose built vibration damper like Dynamat Xtreme.
This turns the value proposition on its head. Using a product like P&S
will cost more, involve more work and introduces a high risk of failure.
Makes no sense at all. If one is lucky, failure means the product just
falls off. If not, the asphalt melts out.
The other widely help misconception is that even a well designed
vibration damper alone will significantly attenuate vehicle noise -
that's a debate for a different day.
On 7/13/2011 8:48 AM, George P Dausch IV wrote:
> Don,
> I thought you might find this interesting.
> GPD4
>
> --------- Forwarded message ----------
> From: Garth Rodericks<garth_rodericks at yahoo.com>
> To: Julian Kift<julian_kift at hotmail.com>,
> De Tomaso List<detomaso at realbig.com>,
> "adin at frontier.net"<adin at frontier.net>,
> Ken Green<kenn_green at yahoo.com>
> Date: Tue, 12 Jul 2011 23:47:17 -0700 (PDT)
> Subject: Re: [DeTomaso] Sound Deadener - Dynamat Xtreme vs Peel& Seal
> Message-ID:<1310539637.7376.YahooMailNeo at web161820.mail.bf1.yahoo.com>
> References:<18507.59645.qm at web161801.mail.bf1.yahoo.com>
> <SNT116-W599D1D089ED5DC5654D54495530 at phx.gbl>
>
> This is a follow up to last month's discussion regarding sound deadener
> products; specifically "Dynamat" versus a much less expensive
>
> alternative found at Home Depot and Lowes called "Peel& Seal Gutter
> Patch and Flashing."
>
> First of all, "thank you" to Kenn Green for sending me a scrap of
Dynamat
> Xtreme to test against the Peel& Seal. Note that the Peel&
>
> Seal is supposed to be equivalent to Original Dynamat. Dynamat Xtreme
is
> a superior product to original Dynamat.
>
>
> Observations:
> - Both products appear to be very similar.
>
> - Both are paper backed on the adhesive side.
> - Both have a foil backing on the opposite side; the Dynamat Xtreme
has
> a shinier foil surface which appears to be thicker in profile than that
> of the Peel& Seal
>
> - Both have a butyl rubber compound between the adhesive side and the
> foil side
> - Both measured .05" thick (excluding peel off paper backing)
> - Although they measured the same thickness, the Dynamat Xtreme
product
> felt heavier or more dense. However I did not weigh the specimens
before
> setting fire to them.
>
>
> Test:
>
> I approximated the test procedure for FMVSS 302 which specifies a flame
> spread rate not to exceed 102 mm/m. I did not construct the test
>
> box/oven per the speck, however I did set up the test apparatus in my
> garage according to the following specifications of the standard:
>
> - 38mm flame height
> - Specimen in horizontal position, positioned 19mm above burner tip
> - Exposed specimen to flame, but did not limit exposure to 15 seconds
> - Note that samples did not meet the size requirement of the
> specification and were too small to calculate per/minute flame spread
> rate.
>
>
> Results:
> 1) Peel& Seal
>
> Flame penetrated foil backing within 15 seconds.
> Butyl rubber/asphalt core began to melt and drip from exposure to
> flame
> The core readily caught fire once the foil was breached
>
>
> 2) Dynamat Xtreme
>
> Foil backing withstood flame for 2 minutes
>
> Butyl rubber core bubbled and became very sticky/gooey, but
remained
> intact
> The core readily caught fire once the foil was breached
>
>
> Conclusions:
> The Dynamat Xtreme product is clearly the superior product in this
> comparison. The thicker foil provided greater protection against direct
>
> exposure to flame, and the denser core material was more resistant to
> breakdown under the extreme heat of the flame, possibly because the
>
> Dynamat product does not utilize asphalt in the core. Both products
cores
> burn with direct exposure to flame; burn rates appeared to be
>
> similar, however the sample size was too small to gather sufficient
flame
> spread rate data.
>
> Given the price difference, I will use the Peel& Seal product as
> originally planned. It will be sandwiched between the firewall and a
>
> stainless steel firewall cover which will provide added protection
> against direct exposure to flame, so I'm not too concerned about the
>
> lesser protection afforded by the foil backing of the Peel& Seal.
>
>
> Cheers!
> Garth
> #4033
>
>
>
>
>
>
> ________________________________
> From: Garth Rodericks<garth_rodericks at yahoo.com>
> To: Julian Kift<julian_kift at hotmail.com>; De Tomaso List
> <detomaso at realbig.com>; "adin at frontier.net"<adin at frontier.net>
> Sent: Thursday, June 23, 2011 2:43 PM
> Subject: Re: [DeTomaso] Sound Deadener [WAS: The Answer: #93 from the
> Icky Old Man Institute of Research]
>
>
> FWIW...
>
> Dynamat Xtreme:
>
> Lightweight elastomeric butyl based core
>
> Can withstand temperature extremes between -65?F and +300?F
> (-54?C to +149?C)
> Fire Classification: Flammable, but meets FMVSS 302*
> No MSDS, merely a technical spec document with marketing information
the
> manufacturer/vendor wishes to share. Unfortunately I could not find a
> published MSDS for Dynamat Xtreme or Dynamat
>
>
> Dynamat (original):
> Styrene-Butyadine-Rubber based core
> Can withstand temperature extremes between -22F to +350F (-30C to
+177C)
> Fire Classification: Flammable, but meets FMVSS 302*
>
> Peel& Seal:
> Styrene-Butyadiene-Styrene block copolymer (10-20%) and Asphalt
(40-60%)
> - Arguably the exact same compound as used in Dynamat, unfortunately I
> could not find a published MSDS for Dynamat.
>
> Fire Classification: Has not been certified against FMVSS302; MSDS
states
> "There is no potential for fire or explosion."
>
> MSDS: http://solutions.mfmbp.com/MFM%20MSDS%20PEEL%20AND%20SEAL.pdf
> Note that I will conduct my own flammability test before installing in
my
> car this weekend.
>
>
> Anyone have a scrap of Dynamat I can set fire to for comparison sake?
>
> There are also other alternatives to Dynamat too, some marketed as
> 'automotive sound deadeners' and others as industrial sound
> deadener/insulation products such as those available from McMaster Carr
> or Grainger.
>
>
>
> * FMVSS 302 was adopted in 1971 and became effective for vehicle model
> 1972.
>
> - This standard set a flame spread rate not to exceed 102 mm/m. This
> was deemed adequate for the occupant to stop the vehicle and exit
without
> serious harm.
>
> - FMVSS 302 is applicable to interior components including seating,
> door panels, headliner, carpet, seat belts, air bags, package shelves,
> instrument panels, steering wheel covers and padding, etc. (note ? this
> is not everything ? just some examples)
> - More details:
>
http://www.a2la.org/conclaves/conclave2009/minutes/Materials%20Testing%20
> Advisory%20Committee%20Summary%20-%20Attachment%201.pdf
>
>
>
> ________________________________
> From: Julian Kift<julian_kift at hotmail.com>
> To: garth_rodericks at yahoo.com; De Tomaso List<detomaso at realbig.com>;
> adin at frontier.net
> Sent: Thursday, June 23, 2011 1:03 PM
> Subject: RE: [DeTomaso] Sound Deadener [WAS: The Answer: #93 from the
> Icky Old Man Institute of Research]
>
>
>
> The Peel N Seal is a roofing product and asphalt based, whereas Dynamat
> is a Butyl based product, so they are not the same.
>
> The asphalt products don't stick as well, smell of asphalt in the heat
> and being asphalt based are flammable, you get what you pay for.....
>
> Julian
>
>
>> Date: Thu, 23 Jun 2011 12:39:06 -0700
>> From: garth_rodericks at yahoo.com
>> To: detomaso at realbig.com; adin at frontier.net
>> Subject: Re: [DeTomaso] Sound Deadener [WAS: The Answer: #93 from the
> Icky Old Man Institute of Research]
>>
>> Looks like it's also available in a 36" x 33-1/2' roll too, but I
> haven't seen this product person to verify it has the same
asphalt-based
> compound.
>>
>>
>
http://www.lowes.com/pd_154032-81326-PS36_0__?productId=3090099&Ntt=peel+
> %26+seal&pl=1?tURL=%2Fpl__0__s%3FNtt%3Dpeel%2B%2526%2Bseal&facetInfo=
>>
>> Cheers!
>> Garth
>>
>>
>>
>> ________________________________
>> From: Garth Rodericks<garth_rodericks at yahoo.com>
>> To: DeTomaso Mail List<detomaso at realbig.com>; "adin at frontier.net"
> <adin at frontier.net>
>> Sent: Thursday, June 23, 2011 12:24 PM
>> Subject: Sound Deadener [WAS: The Answer: #93
> from the Icky Old Man Institute of Research]
>>
>>
>> David,
>>
>> Nice post. I like the videos. Is that your GT40 in the Fernley video?
> Looks and sounds beautiful!
>>
>> Anyway, I was researching less expensive alternatives to Dynamat and
> came across a recommendation for "Peel& Seal" gutter patch and
flashing,
> available from Lowe's for $15 a 25' rool (6" wide).
>>
>> http://www.ratrodsrule.com/forum/showthread.php?t=3226
>>
>>
>> Supposedly the same stuff as 'original' Dynamat. I'm putting this on
> the firewall and hatch cover in my Pantera.
>>
>
http://www.lowes.com/pd_154017-81326-PS625_4294934213_4294937087_?product
> Id=1018733&Ns=p_product_prd_lis_ord_nbr
>>
>> Cheers!
>> Garth
>> #4033
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--
Don Sambrook
Sound Deadener Showdown, LLC
410.458.6418
don at sounddeadenershowdown.com
http://www.sounddeadenershowdown.com
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