Re: REFLECTOR: Door Trim Sealing

[Lloyd L Garner <lgarnerx@juno.com>]

Greg and Joe:-

Sealing problems on heavy iron (F4, F15, DC10, etc) were usually  cured
by tighter tooling control to keep the gap at the proper space to achieve
optimum compression on the bulb or whatever.  Canopy and door seals were
invariably inflatible types to compensate for manufacturing
irregularities and structural warpage with age and flight hours.. 
Prototypes and experimental birds were usually constructed with minimal
tooling and were real bitchy to get good sealing.  In one case we
actually rebuilt the door in place on the fuselage to get it to fit and
seal enough for presurization.

I too am not to the point of fitting doors, but can surmise from what has
been posted that the basic problem is the varyinng gap that occurs.  This
can be fixed by using a larger and softer bulb seal (as Joe suggests)
that will operate between 25% and 50% compression.  Greg's reinforced lip
idea would help stiffen the door edge, but do little to control gap
unless you built it up  high enough and then hand fitted it by grinding
excess glas off where the gap was too small.  That will work but it's
plenty of WORK!
            
Finally got aproblem where my 2c is worth at least one cent.


On Sun, 25 Jul 1999 08:49:41 +1100 gpoole@zeta.org.au (Mr Greg Poole)
writes:
>Hi Joe,
>
>While I am not up to this stage with my STD RG E yet, ANY cabin noise
>reduction is of major interest. Am very keen to hear if any 
>improvement can
>be accomplished.
>
>I do not want to replace the factory supplied trim with Piper trim 
>like Jim
>A. recommended unless all else fails - so am interested in whether a 
>raised
>bead on the edge of the door to squash down/ensure contact with the  
>trim
>seal provides any advantage. Figure a semi convex surface on the bead 
>might
>contact the trim seal rubber without causing the door distortion that 
>is
>likely  if the entire seal was contacted and flattened against the 
>door
>edge. ...Bead would be in line with the red arrow in your neat 
>diagram.
>
>Thanks for persuing this one for the group!
>
>
>Regards,
>
>Greg.
>
>Greg Poole
>(Building a Std RG Elite Down Under)
>Velocity Aircraft Australia/NZ
>
>

Lloyd L Garner, PE    173 Elite RG    DMO333  
Retired MDC Fighter Engineer and 1952 Parks College Grad
Life is like driving the freeway --- Slow down and you'll get run
over!!!!