Window Runners and Felts Replacement

Its a fairly common thing for the skin along the top of the door liners of a 928 to become loose over the years as the glue holding it down degrades and lets go. The result is that it just looks a bit daggy. Its a fairly easy repair though.

Door liners also tend to suffer water damage. My guess is that over time the felts that hold the window out against the seal wear and collapse. This allows just a little bit of water to get in every now and then (especially when the car is washed). If the original plastic coverings have been removed (as many have), then its highly likely that the bottom of the moulded fibre door liner will be water damaged.

To do this job properly you need to do things in the right order. Examine the bottom front edge of the liner for water damage. It is easy to spot as the fibre board will have expanded and become soft. If this is the case, I would strip the carpet off the bottom edge as it will likely have delaminated and be loose.

The carpet is held on by contact adhesive, and short staples. The staples will pull out easily, especially if there is water damage. Pull back the edges then peel the carpet off completely. Its pretty robust, so you can't really hurt it.

Next, look over the vinyl skin (or leather?). Mine was in good condition and only had a few loose spots where it had come loose around the edges. Therefore I decided to leave it on and re-attach the edges.

The thing that surprised me most was how dirty the liner was, on both sides. So I took the liner outside and wiped it down with a damp (not wet) cloth to get the dust off. I followed this with a brisk rub down of all the fibre board surfaces with a course sand paper to help knock off a bit of the old glue and loose material. No need to over do it though. Then wipe down again.

As you are doing this work be very careful not to mark or damage the vinyl skin if you have left it attached. Its easy to do, as the panel is large and tends to get bumped on things easily.

The carpet I removed was pretty dirty, so I wet vacuumed it with carpet cleaner. The result was rather surprising. The carpet came up looking just like new! I was very pleased. Don't forget to let the carpet dry properly before you try to re-attach it.

The easiest way to do this, is to use thinned epoxy resin. for one panel I used about 100 mils of resin thinned with 50 mils of epoxy thinner (note: acetone thinner will not work!). Thanks to David from Landsharks for this idea. I believe it originated on the Renlist.

Mix up the resin and thinners. This will give you a very liquid mixture, use a paint brush to apply the resin to both sides of the panel. You are trying to saturate the material so be generous. More is better than less in this case.

Let the resin cure fully, then give the surface a light sand, followed by a wipe over with a damp cloth.

As the vinyl skin overlaps the carpet, you need to put the carpet back on before you glue down the vinyl. I used automotive grade contact adhesive for this job. From what I can tell, its pretty much the same as the original adhesive that Porsche used.

The first job is to clean the back of the carpet. It will be covered in old glue, fibre and dust. I used a paint scraper for the job, which seemed to do just fine.

Apply a liberal coating of contact adhesive to the front side of the door liner (that's the side that the carpet attaches to). Don't worry about the other side for now, but do ensure that you run the glue right out to the edges.

NOTE: Don't put glue in the depressions where the panel clips attach! You want the carpet to sit smooth over the top and hide them.

Carefully coat the back of the carpet all the way to the edges. You will need to wait the edges down as you work, because the drying glue will make the carpet curl up. This is bad (like crossing the streams!). You will either end up with the carpet stuck to itself, or glue all over the face. Either option is not good.

As the carpet is pretty porous you may want to apply two coats for best bonding. I only did one, which was ok, but not as firm as I would have liked.

Note: Don't thin the glue when working on the carpet! This could lead to it leaking through the backing into the carpet pile.

Leave the contact adhesive to dry (10 to 20 minutes probably). When its ready then lay the carpet down on the door liner. I started with the hole for the courtesy light. Its a good way to get things properly lined up. Then lightly tap the carpet down along the lip of the pocket in the door liner, this is another good marker for alignment.

Once that is done, work from the top down to the bottom, carefully smoothing down the carpet so there are no wrinkles.

Once its all glued on, turn the door liner over. Apply a good thick coat of glue to the flap of carpet that protrudes around the side and to the edge of the door liner. Allow to dry again, then fold the flap over working back and forward along the entire edge, just doing a little bit at a time. This will help avoid wrinkles.

If you haven't had to remove it entirely (like me), then its a pretty simple job. Peel back the edge flaps where the vinyl has become slack. Apply contact adhesive to both the vinyl and the door liner. Allow to dry then pull the skin taught (not tight!) and press down on the door liner.

Now that the door liner is all patched up I would take the time to give the door handle and all the plastic components a good clean. I washed them in hot soapy water. Its just a bit easier to do them thoroughly while they are off.

Part of the reason my door liners were water damaged is that the plastic skin that is meant to cover the inside face of the door had been removed from both. As a result any moisture that did make its way past the weather seals had a good chance of getting onto the door liner.

I had one of the damaged sheet, so I bought some clear sheet plastic (clear is best as it makes it easier to align things) and cut new skins for both doors. The skins can be attached with contact adhesive, which is how it was originally done. This gives good results, but is hard to make neat. To practice, put the adhesive on the door panel and allow to dry. Then practice positioning the plastic until you are happy with the coverage.

When you are confident, then apply the adhesive to the plastic (sparingly), let it dry and bring them together.

As you managed to get door liner off I will assume that you can get it all back together again.

The door liner is partly held in by plastic clips. There are 13 of them on each door liner. 11 grey and 2 black. I would recommend replacing all of them while you are doing this job. Some will be broken, others worn. If you want a really tight fit then replace the clips. Oh, and incase you didn't mark it when you took them off, the two black ones (shorter that the others) go in the back top corner of the panel near the door lock.