Date:         Thu, 25 Mar 2004 07:59:12 EST
Reply-To:     THX0001@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         George Goff <THX0001@AOL.COM>
Subject:      Re: Sound Deadener Installation Concerns
Content-Type: text/plain; charset="US-ASCII"

In a message dated 3/24/04 5:24:29 PM, vanagon@ASTOUND.NET writes:

<< . . . In the old days we used undercoating and fiberglass matting and
built it up on the

inside of the doors. It really makes the whole vehicle feel allot more

solid.  I would hate to be the body guy now having to scrape that crud off

the inside of the quarter panels we did.. . .


. . . The stuff in the back of your vanagon over the engine deck, behind back
seat

and up front in the footwells is definitely there for sound deadening and

heat insulation. It is put on very well to not allow water to easily get in

between the metal and the material.  If you have ever removed any of it, you

will notice it is very well stuck on.  . . .


. . . Anyway, if you want an alternative to Dynamat get some heavy
construction

felt like #30 or #60 and cut it into the shape and use a MILD contact

adhesive that will keep it attached for then next 10 years or so like 3M #77

spray on adhesive, it is not that strong of a bond use it sparingly and you

will be able to remove the asphalt felt at a later time. . . .  >>

In the old days in my part of the world, bodymen would apply an extra charge
for work done on a car which had been rustproofed because of the hassle of
dealing with all the goo.

The asphaltic sheets in the Vanagon are definitely in place to dampen panel
resonance, but I don't know about their usefulness as heat insulation.  Anyone
who ever had the occasion to stand on a built-up asphaltum roof in the middle
of August might agree with me.

Tar is great stuff, but it can be a mixed blessing.  Whenever it is warm, it
will conform and stick to nearly any dust-free surface.  But, if cold enough,
it becomes as brittle as a witches tit.  Coupled with the different expansion
rates of various materials, asphaltic sheets can delaminate from the surface
to which they are applied.  That is exactly what I found when I pulled up the
front carpeting in my van.  Under the loose asphaltum I also found unpainted
floor metal.  I caught it before it rusted, but if left go with that moisture
trapped beneath the loose sound deadening material would have been the perfect
recipe for rust.

Don't think that you can dodge the bullet by living in the Promised Land of
Southern CA. Condensation, a spilt cup of coffee, a minor leak in a heater core
and who knows what else can cause moisture to be entrapped.

Using roofer's felt stuck on with some contact adhesive is the worst idea.
If you speak to a mall owner, you will find that their biggest problem and
ongoing expense is locating and repairing roof leaks.  And their roofer's felt is
stuck on with asphaltum heated to several hundred degrees.

George