Author Topic: Hardtop vents - a question ?  (Read 3490 times)

66andBlue

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Hardtop vents - a question ?
« on: February 28, 2007, 10:53:00 »
Hi all!
Above the rear window in the hardtop are small slits [panel 1]. What is their function? Poking around I could not find a connection to the inside.
On the other hand the area underneath the bigger holes around the perimeter and along the 2 pillars [panel 2] is open to the outside via two holes at the bottom of the pillars where the top rests on the chassis [panel 3].  But the holes are so small that they wouldn't allow much air flow.  
I am asking because I am thinking of covering the hardtop with Dynamat  - as Tom in Boise did - instead of a soft foam layer and am wondering whether this would totally cut off any venting if it is required.
 :?: Any thoughts on this, anyone  :?:

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Alfred
1966 blue 230SL automatic
« Last Edit: February 28, 2007, 10:54:35 by 66andBlue »
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

rwmastel

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Re: Hardtop vents - a question ?
« Reply #1 on: February 28, 2007, 20:37:34 »
I thought the perforations in the head liner allowed air out.  Circulation keeps the glass from fogging.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
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Rodd

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66andBlue

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Re: Hardtop vents - a question ?
« Reply #2 on: March 01, 2007, 21:21:21 »
quote:
Originally posted by rwmastel

I thought the perforations in the head liner allowed air out.  Circulation keeps the glass from fogging.

Rodd,
that is correct but in addition I was wondering whether the air needs to move past the foam layer underneath the headliner to the outside.
 So I talked with Gernold and he is sure that the narrow slits above the rear window are the exits through which cabin air flows outside. He has seen crumbling foam in old hardtops blown out through the slits when a door is closed. The reason why one can't find an exit poking with a wire is perhaps a screen or something similar with very small holes to keep insects and other critters out.
He also mentioned that the two holes on each side in the bottom rim are water drain holes. [Thanks Gernold for all the info!]
So what this means is that I need to cut holes into the sound damping mat (such as Dynamat's TacMat) underneath the headliner in the pillar section to let the air go out, or use a foam layer only in those sections.

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Alfred
1966 blue 230SL automatic
Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)