Targa Glass Base Moulding/Trim Assembly

[WMichelsen]

Targa Glass Base Trim/Moulding
There are several threads about R&R the Targa Glass. But, I didn't find much discussion of the base moulding and installation details. I had (and still have) a few questions. So, here's what I found and did.

Parts reference:
Moulding/Trim: 911.565.049.40
Seal: 901.565.557.40
Butyl Tape: 000.043.129.00

I've had this car since 1991, and it was untouched before that. So, I'm 99% certain what's original or not. The RHS had shop repair at one time, requiring R&R of the glass and probably trim. So, I can't be certain regarding the glass seal itself. But the LHS moulding should be as Porsche factory assembly.

The PET makes it look like the it stacks bottom to top as:
0-Car Body, 1-Trim Seal, 2-Metal Trim, 3-Butyl Tape, 4-Window Seal ...
with the butyl tape running the whole base perimeter.



Upon disassembly, here's what I found:
The rubber seal appears to be attached to the metal trim with adhesive
The butyl tape is applied mostly under the metal trim.
The butyl tape does not extend beyond the metal trim.




So, for reassembly, here's what I did:
I had some double-sided tape on hand. I cut sections and split them from 1/2" width to 1/4". That better matched the rubber seal width. Then, applied the tape to the metal trim, and then the seal to that. After that was done, then I applied and trimmed the butyl tape. I opened up the screw holes with a blade, then installed the trim to the car.





I am looking for confirmation or correction here. I was working from what I discovered on disassembly, and tried to match it on reinstall. Please let me know if something is wrong.

[WMichelsen]

BTW, I also replaced the rusting screws with stainless-steel ones. Any issues doing that?

[Mark Salvetti]

Wayne, that looks like quite the challenge.

The concern with the stainless screws in the steel body is galvanic corrosion. If moisture gets in there, the galvanic corrosion will accelerate the corrosion of the steel body where it is in contact with the stainless. I think you may be better off with steel screws that are zinc plated, and protect the threads with a coating of never-seize.

https://forums.pelicanparts.com/porsche-911-technical-forum/1070780-stainless-steel-fasteners-can-bad-thing.html#post10996098

The steel screws worked well enough for over 30 years, and will likely last even longer given these cars are no longer daily drivers.

Mark

[WMichelsen]

Mark, Good point about galvanic corrosion. I didn't know they were that that far apart in compatibility. Thanks.

[RDM]

Mine had a thick deposit of what resembles plumber's putty all the way across the back. I did not replace it, and as a result my window sits low at the bottom center.