Dark Blue

To my horror I just noticed two tiny bubbles (less than 1 mm (sorry no pics yet)) bubbles in the paint under the rear quarter window rubber trim on my pristine 89 S4. My car has always been garaged and well cared for, so I assume that someone chipped the zinc coating while replacing the quarter window at some point.

I've owned a bunch of Fiats in my time, and I hate rust. I've owned the 928 since 95 and plan to keep it forever, but this rust has got me worried. Is there any good way to stop/repair these tiny blisters without doing more damage than good.

Any suggestions are much appreciated. Thanks.

Steve
89 S4

Rob Edwards

My GT is at a body shop in Anaheim right (friend of Greg Brown's) now having two rust bubbles fixed in exactly the same place (forward third of the lower edge of the right quarter window). The car has been in SoCal all its life but at some point I think it was hit in the RR corner and repaired (don't have the PO's receipt for THAT one......). No rust is visible directly but the bubbles are about 1 cm in size now, and they're just gonna get bigger, so it was time to fix them. The window moulding along that lower edge was starting to get bowed out....

I already had a right rear quarter window gasket (928.543.038.04) that I gave to the shop, to save them the time & hassle of having to source it themselves.

I'm picking it up on Thursday and will have a report with the before, during, and after pics.

Gtaebr

Sand to bare metal, apply rust stopper, prime and paint.
Works every time!
As long as you catch it early it is easy, when a Fiat looks like Swiss cheese it is more of a replace panel job. Thankfully comparing corosion characteristics of Fiat to 928 is about as far apart as you can get. Of course Austin Healey would give the Fiat a run for the money!

Marine Blue

Known problem with our cars and a design flaw IMHO. After washing the car the water will sit inside the seal forever unless you use compressed air to blow it out. If the car doesn't get wet it won't get worse unless it sits in a humid environment. It definitely should be addressed when possible.

JCruize

I have an '88 model that had the exact same issue. Two small paint bubbles about 2 inches apart on the passengers side rear window. It is in the shop now and they tried to sand and treat the areas affected, but it was to thin. He then tried to weld in some material but it would just blow out more. The final solution was to drill them both out to about 3/4 inch an weld in a disc. This seems to be the best solution in my situation and I am happy with they way it turned out, just wish that it wasn't so much work. I was told that if we did not get all the rust removed that it would come back a quicker

While you are at it be sure to look under the sill plate, I had a surface spot of rust that we caught in time and they just sanded and treated it.

Rob Edwards

Here are 2 'before' pictures of mine, not perfectly representative but you get the idea:

Rob Edwards

Followup-

I picked up the car today, they took some pictures for me during the repair. You can see the two small areas of bubbling still under the paint, but check out the amount of additional rust in the window channel. Yikes.... They did a fantastic job of repairing it, as shown in the last pic- doesn't do it justice. They also detailed the hell out of the car. Total cost was $800ish, not including the window gasket that I supplied. Shop is Anaheim Hills Auto Collision Center, ask for Bruce.






After:

Marine Blue

Rob thank you for posting the follow up. Did they respray the entire rear quarter or did they only respray underneath the window seal and in the channel?

Gtaebr

Way to go. That paint buffed out a treat and you have the value of original paint.
Let's see some shots of the whole beasty!

Rob Edwards

Afshin-

AFAIK they only sprayed around the repair area, not the whole quarter. I was concerned about keeping as much original paint as possible.

The rest of the car, cleaned up:

Marine Blue

That is awesome. I know many will benefit from this post as this is a known problem area for many sharks.

The GT is looking fantastic. Must be nice to have it all back together.

Rob Edwards

Followup #2:

The picture of the GT above doesn't capture an important side-effect of the trip to the bodyshop- When I went to pick up the car, the detail guy was finishing up- they pulled the car around front and immediately I noticed that they'd sprayed something caustic on my CS wheels that had been freshly re-anodized 2 years ago:



The owner of the shop owns a beautiful early 911S and knew immediately that they were toast, so he had me take them over to Al Reed, who polished and re-anodized them for me, on Bruce's nickel. I picked them up today:





Anyway, mad props to Bruce Witkin at Anaheim Hills Auto Collision, who did a great job on the GT's paintwork, and who stepped up when one of his guys made a mistake.

Shark_Week

car looks great Rob
i hope mine comes out looking that good. i may have to give Bruce a call as i have a half dollar sized corrosion spot on passenger side door just below window seal. doesn't look good and want to take care of it soon.