Recovering the seats

[LoneWolfGal]

Since disassembly at the hinge has turned out to be a thrash, I'll cut the Gordian knot and simply swap the cushions themselves — i.e., install the new cushions, back and bottom, on the original seat's frame as well as the original seat's cushions on the new seat's frame. By the way, I bought a leather cleaner and conditioner kit by Chemical Guys, a brand with high marks, including for its scent. Seems many conditioners have an objectional odor, but Chemical Guys' product smells like leather. I'm going to clean and condition both seats to a fare-thee-well before I install — or rather, wrestle — them back in the car. I found Chemical Guys' how-to video informative:
https://www.chemicalguys.com/blogs/interior-how-tos/how-to-clean-and-protect-leather-car-seats

[LoneWolfGal]

Before removing the leather from the cushions preparatory to installing the heater pads, I wanted to make sure it was soft and supple, so I hit it first with Chemical Guy's leather cleaner, followed by two applications of conditioner. The leather looked pretty good before but the difference is noticeable. Have a look at the bottom cover. (The leather has been detached from the the rigid plastic seat form underneath the foam, which is why it looks somewhat loose.)

[LoneWolfGal]

I intended to start a new thread documenting the conversion of my new seat from unheated to heated, but I think I'll just continue spewing in this one. There are plenty of videos and how-tos that show how to add a heat pad, although most use after-market products. My heat pad is OEM, out of the original drivers seat. Here's a look at it after I used spray adhesive to glue it in place on the foam seat cushion. Gluing is necessary. You don't want the pad moving around under the leather..



As you can see, I opted to go with nylon pull-ties instead of hog rings, the original method of attaching the leather to the seat cushion. I do have access to hog ring pliers and hog rings and I fully intended to use them. But after messing around with them a while I tossed them aside. My resistance to them might have something to do with what a thrash it was to remove the original hog rings. My wire cutters weren't up to the task, even though they had clipped other hog rings with no problem. Go figure. Maybe Porsche used titanium hog rings on this particular seat. I ended up using a Dremel with a metal-cutting blade instead. Pull-ties are much, much easier to deal with, You simply thread them around a wire rod at the bottom of the slit in the foam. You don't have to wrestle the foam aside and try to get hog ring pliers down there where it's hard to see what you're doing, while the leather itself fights you. You simply pull nylon loops tight. I have every confidence the pull-ties will last well into the next century. In 2124, when my 986's owner needs to replace the leather, it's a matter of merely snipping the nylon ties, no Dremel necessary.

I'm now in the process of finishing installation of the leather cover after securely zip-tying it to the foam cushion, which sits in a sculpted plastic seat base. The leather needs to be stretched around the bottom edge of the base and secured with a flexible plastic channel around the inside edge of the cover. The leather was pretty tight before I removed it. Adding a 3/8" thick heat pad to the cushion will make it even tighter. I'll need to stretch it considerably before I can secure it in place. I'm using clamps around the bottom edge to stretch it. From time to time I stretch it a little more and clamp it again. Tomorrow I'm going to try heat from a hair dryer to stretch it even more. I've also enlisted the help of a couple of manly volunteers who can compress the foam for me to give the leather yet more slack.

And I haven't even gotten to the seat back yet.

[LoneWolfGal]

The clamp method, I'm happy to report, is a rousing success. Here's the technique I used. I first seated the leather cover's plastic channel at one spot on the base's edge and secured it with a beefy clamp. Then ten or fifteen minutes later I added another clamp about an inch further down. And then another an inch down from the last one. I proceeded in that manner all the way around the base's edge. A clamp can exert far more continuous force than any human hand. You can let them squeeze all night, which is what I did to make the progress you see here. Only one stipulation: You gotta have a lot of clamps, which might involve a trip to Home Depot or Harbor Freight. You can pick them up for a buck or two apiece. You'll want at least a dozen. I had 13 on hand.

This seat has eclampsia. The front was especially stubborn, so I'm going to let the clamps stabilize it overnight.

[LoneWolfGal]

Compared to the seat bottom, adding the heat pad to the back insert was a piece of cake. I found the holes used by the hog rings were too small to fit the pull-ties through, so it was necessary to drill 1/8" holes in the retaining plastic. The easiest — in fact, the only way to accomplish it cleanly — is to do it from the underside (see photo). The plastic isn't attached, so it can be lifted away from the foam to get a clean shot at the target with the drill, three holes per slit, nine in all.



Whoever installed the original hog rings must have been a neophyte. A few rings missed the plastic entirely. The pull-ties attached the leather to the cushion much more securely. In case you haven't noticed, I'm big on pull-ties for this application.



All that remains is to hook the leather at the bottom and the seat insert will be finished. You really have to reef on the leather to hook it together, due to the thickness of the heat pad. I couldn't do it alone, so I enlisted a pair of strong hands to assist.



Next, I'll join the seat back and bottom by bolting their respective frames together. After taking care of a few details, such as pull-tying the wiring in place under the seat, it will be time to wrestle the seats, both heated, back into the car.

[LoneWolfGal]

The bottom cushion's ready to clamp onto the frame. And "clamp" is the right word. Two beefy nylon clamps at the front and one lonely Philips screw at the back are all that holds the cushion and its base in place on the frame. I was sorta expecting a more convoluted fastening system from Porsche. Maybe they felt bad about making you disassemble a good part of the underside, including unbolting a couple frame struts, to change the transmission oil, or making you unhook a bunch of hoses underneath (after of course removing the plastic belly pan) to drain the coolant system for flushing. Things like that. So maybe they decided to cut us a break with the seat fastening method. But I digress...

I direct your attention to the bottom frame and its seat adjustment mechanisms, below. Everything was coated with 24 years of grime. I couldn't stand it, I had to clean it up. The grime must've acted as a protective coating, because everything cleaned up beautifully and looked almost new. I'd like to install the bottom cushion tomorrow. And then I'll clean up the underside of the passenger seat. I took a look underneath it and it wasn't as bad as the drivers seat was, so it shouldn't take long.

[LoneWolfGal]

UPDATE:

I encountered a setback just as I was about to mate the bottom cushion with the frame. The one-inch-deep crack between the left bolster and the center section had become a shallow crack barely a quarter-inch deep and the bolster's leather looked flaccid. Porsche's method of attaching the leather at the bottom of the crack was suspect. It involved seating a plastic bead the length of the crack into five plastic clips (see photo below) at the bottom. It looked dubious to me when I took it apart because it depended solely on the claw-like clips. But I shrugged and reassembled it the same way. And I assure you, the bead was seated in the clips, thanks to a tool I built out of a quarter-inch dowel with my Dremel. The seat looked perfect... until the seam's attachment point became detached. I sighed with resignation and then I peeled off the leather that covered the left bolster.

Just as I suspected, part of the bead had pulled out of the clips, but there were also a couple plastic clips, still attached to the bead, that had pulled out of the seat base. The clips are mounted on the inside of the contoured seat base into which the cushion fits. They're called "expanding clips." The bottom part of it is pushed through a hole and then it expands, securing the clip. I left them in place on the seat base when I took it apart.



So I had two points of failure, two problems to solve. Keeping the bead locked in the clips was an easy one: pull-ties to the rescue. But first I had to drill a hole through each clip for the pull-tie to go through (see photo above). A bench vice I picked up at Harbor Freight was indispensable for the task. As for the clips pulling out of the holes, I used tiny dowels (a.k.a. wooden toothpicks) to prevent the expanding part from collapsing and slipping back through the hole.



My workarounds solved the problems. I replaced the bolster's leather, now tight once again, and had a Coors to celebrate.

To be continued...