Protection of the cardboard panel of the doors

[bert huygens]

Hi guys,

I had to buy 2 new cardboard doorpanels because the original ones were in very bad condition. They probably got wet during the past 30 years.
I want to prevent now that the new panels get wet. Would it be a solution to spray the panels with glue and cover them with a thin plastic sheet? What do you think? Or do you have other solutions?

Greetings,

Bert

[Tom]

Hi guys,

I had to buy 2 new cardboard doorpanels because the original ones were in very bad condition. They probably got wet during the past 30 years.
I want to prevent now that the new panels get wet. Would it be a solution to spray the panels with glue and cover them with a thin plastic sheet? What do you think? Or do you have other solutions?

Greetings,

Bert

Get new vapor barriers from Porsche! They are thicker than I expected and seal the door very well. They were still available from Porsche when I got mine in 2020. Part numbers are 944.555.178.05 and 944.555.177.05 They were about US$30 each, left and right.

944-door-plastic.jpg (1.07 MiB) Viewed 1997 times

[Zirconocene]

I would recommend a couple of things.

I'm not going to argue with going OEM, that's never going to be a bad choice. However, you can also buy nice, thick shower curtains and cut them to size easily. It's quite inexpensive and can be quite thick. I don't know about the 944-type cars but on the 928 there are additional, separate parts of the vapor barrier that sort of hang into the door to make sure that any water that makes its way in gets routed to the exit points. If it's not already a part of the way the door vapor barrier is set up, maybe it's something you can incorporate. My reading indicates that something like the non-permanent putty that is used to hang pictures can be used as an adhesive for the plastic.

More importantly, the preferred way to make the door panels waterproof on the 928 is to use fiberglass epoxy. Maybe that's what you meant by a glue, but you certainly don't want to use something like white school glue as that loves to dissolve in water and would be worse than what you started with.

I'm still going down this road with one of my 928s so this is all from my reading and preparation, no direct experience just yet.

Good luck

[Darwin]

@Tom Thanks for the PNs! I should get those ordered. My issue right now is trying to repair the existing cardboard backing. I have some of the clips that have ripped the door card and I've been trying to think of ways to repair/restore functionality/integrity.

[usury]

On my 944, the cardboard door cards were still in decent shape, thanks in no small part to the still intact plastic moisture barrier.

However, I went a step further and applied a "3M Scotchgard" waterproofing spray (green can) to the back side of each door card. It's designed for camping gear. I've used it on motorcycle denim pants for a degree of wet weather protection, and on motorcycle covers to restore a degree of rain protection.

It's not perfect nor actually waterproof. In conjunction with an intact plastic moisture barrier on the door however, it should help ensure the door cards last another 35 years. I did this with the rear interior panels as well.

As far as (re)adhering the moisture barrier, I used a common Elmer's glue stick. The kind kids use for construction paper projects or scrapbook projects. It is sticky but not super sticky. You can peel and reposition after application. It's not messy like the black butyl rubber stuff I've seen recommend on other forums. And you might already have some at home.

[usury]

My issue right now is trying to repair the existing cardboard backing. I have some of the clips that have ripped the door card and I've been trying to think of ways to repair/restore functionality/integrity.

I know you posted this months ago. For the benefit of others who find this post in the future, I repaired similar damage around my door card clips, and the clips in rear interior panels too.

I used a high strength spray adhesive like "3M 77" to attach new strips or squares of thin cardboard to the damaged sections of the back side of the door cards, cutting holes and capturing clips as needed. Do this before any water proofing spray (since such sprays probably contain silicone which makes sticking stuff to it pretty impossible).

When I say thin cardboard, I mean like a cereal box. Anything corrugated would probably be too thick.

I don't seem to have any photos of this repair, unfortunately. Hopefully the description is helpful enough to give the next person finding this post a starting point in approaching their repair.