jwbeck17

Was just looking some door trim removal pics and realized I haven't seen any door liners, or plastic sheeting between the interior trim and the door mechanics to keep moisture out of the interior, which is often used in other cars. Is that not needed in 928s?

dr bob

jwbeck17

Fantastic. I have an extra shower curtain that I realize could work as a replacement sealant. The adhesive tips are very helpful too. Thanks!

jpitman2

Dont think the doors are steel, Dr Bob! Mine fell apart once removed, and had to be replaced with something a bit heavier. I used hot glue in steps starting from the top, once I had the sheet all cut out. Easy to trim, and punch holes for card attachment clips and bolts.
jp 83 Euro S AT 57k

Mrmerlin

Petza914

On my 814 and 928, I remade the moisture barriers using Tyvek home wrap. Very tough and durable, yet easy to cut and work with. I attached it with the blue putty sticks you hang stuff on concrete dorm room walls with - sticks when you need it but pulls off cleanly when you need to get access behind the barrier again.

In the areas where there would be large voids, like where my 6 1/2" woofers are mounted in the doors, I put those speakers in with BoomMat enclosures.

Wisconsin Joe

There should be a plastic vapor barrier, along with drip panels, between the door and the door card.

Many (most?) are missing or in tatters.

Any reasonably strong plastic sheeting will work. MrMerlin suggests using a shower curtain, which is a readily available and reasonably strong plastic sheet.

Drip panels are smaller sheets that are cut to fit the width of the openings in the door, but are a bit longer. They attach at the top of the opening and push through to drape down inside the door shell. They keep drips of water from ending up at the bottom of the door card (hence the name 'drip panels').

The vapor barrier is just cut to size on the door and glued into place. MrMerlin suggests using Weldwood contact cement. I didn't have that, and used 3M 77 spray glue instead. It has worked for me, and has the advantage that if I go into the door and peel of the vapor barrier, I can just press it back into place on the existing glue.

It makes a huge difference in the sound of the door closing. Goes from 'tin can' to 'bank vault.' (really)

This has come up before, and Rob E had a pic of the dimensions of it:
https://rennlist.com/forums/928-foru...r-barrier.html

Thread with pics of it:
https://rennlist.com/forums/928-foru...anels-off.html

dr bob

The original plastic in my car is held on with this glue. I like the spray version for the edges of the replacement plastic, as I can do the initial spray away from the car. I take advantage of the glue that's already on the door, softening it with a little brake cleaner mist. That way I'm not spraying glue with overspray, and no need for a lot of masking. The combination gives enough grip to hold the plastic in place for door panel installation, but weak enough that the plastic can be removed when needed later when access is needed.

Yellow weatherstrip adhesive in a tube is like jellied contact cement, and does a great job holding the flap that drops through the large opening in the door. Follow the direction on the NEW tube; opened tubes have a short shelf life unless stored well. I keep mine in the freezer in the utility fridge, thawing them when needed. Still, new seems to work better and is for sure a lot easier to spread with a throw-away "acid" brush. Your favorite POLAPS stocks them. The yellow brush-on contact cement is getting tougher to find in California these days, due to APCD and AQMD concerns. Little cans are all you find at retail level. It's plenty for this project, fortunately.

jwbeck17

As usual, such a great wealth of information here and thank you. I'm setting up my plan to ensure my car interior is nice and dry, as I am replacing the front seat leather soon and want to make sure the interior is nice and dry so I can enjoy that leather smell! Will be investigating the sunroof, door seals, roof drains and hatch seal too.

928NOOBIE

I got a hot water heater blanket....fiberglass backed...

Made templates (3 per door I think) and cut the pieces.

Used spray adhesive and put them on door...fiberglass facing the interior. Did an awesome job of quieting things down...and was cheap...for some reason I wanted to see what I could do to quiet things down but not put lots of money/weight in...

Its been working awesome. i used the original plastic...3m spray adhesive...I specifically stayed away from the Space Shuttle Approved space age spray adhesive..that way when I need to get in...just peel back.and reapply cheap 3m easy-to-peel spray adhesive...the door panel keeps it in place..I like that it lets me peel the plastic back...and please now applaud my super amazing rattle/noise/insulative protective invention by creating an off-label-use-for-hot-water-heater-fiberglass-thermal-blankets...thing

You're Welcome.

Ghosteh

What about sound deadening material (Dynamat, Hushmat, etc.)? Has anyone used that together with a vapor barrier, or maybe as a replacement for one?

Not to go off topic too far, but I'm curious about how it is applied & if it's worthwhile.

Petza914

Those products are like tar sheets with an aluminum foil backer on them. They're applied by sticking the sheet down and then rolling over it to form it to the surface underneath. You could use it on the inner side of the exterior door skin itself for noise reduction, but it's not the right stuff to go on the inside of the inner portion where the moisture barrier goes. Removing that stuff is an awful job for when you'd need to get back inside the door cavity.