pi5tolpete

As many have experienced, I have found that my paint below the windshield on bot the drivers side and passenger side is blistered. I took a stainless steel rotary wire brush in my Dremel and removed the flaky paint. Underneath is nasty looking rusty metal, but feels intact and I don't plan to replace metal at this time. My plan is listed below. Can anyone suggest additions or other options? BTW - the windshield will come out near the end of driving season for replacement, so I'll get the guts of the rust then, but for now I plan to peel back the seal and get to as much of the rust as I can.

-Wipe area with rubbing alcohol to remove any wax and grease
-dremel loose rust away. use a pick to get stuck flakes.
-use "rust converter" to kill the rust and leave a primeable surface
-mask area just beyond rust spot and leave 1/4" of painted surface exposed
-prime with self-etching primer spray can
-use glazing putty to fill and level, using small thin layers
-allow to dry, sand between layers, until even with surrounding material
-spray leveling primer to check evenness
-paint with colour match in aerosol form
-finish the part I cant reach when the windshield comes out.

option B
-treat the spot temporarily now, and do the full meal deal when the windshield is removed later.

pi5tolpete

attached pic of offending passenger location

deadendd9009

No matter what you do, the rust will return unless you have someone cut that metal and weld in a new piece. Save you money (and energy!) for a professional fix.

greg1990964

Disagree. Grind to bare metal, treat, fill and paint. It will last a long time as long as ALL cancer is removed.

creaturecat

imho: short term - put some por 15 on it. waste of time making it try to look pretty
do the proper repair when the windshield is removed.

newsboy

You can use POR 15 as a temporary rust preventive. They also sell a marine cleaner, & PH prep, to be used before the POR 15. Have used the product many times, and it works well.

RMTPGI

Just completed a similar repair in 1990 C4 Targa and have complete set of pics showing all of the steps. Repair was done by local shop that specializes in panel repair and also does restoration work.
A concern was getting the windshield out of it's 26 year old fitment without damage so we had a glass guy come in and do it. The factory windshield install included copious amounts of older chemistry gasket sealant that had been injected into the gasket and channel that 26 years had cured rock hard. Even after cutting it away there was still plenty holding the glass in place that the final "pop" to free it wasn't easy. For the install, spend the $$$ and get the OEM windshield gasket. Glass guy would not use an aftermarket gasket. Suggest you don't do anything until you pull the glass because you will find the rust continues behind the windshield gasket and into the windshield channel. Also, if your rust is on the passengers side be prepared to deal with the antennae wire from hello. It connects the wire in the glass with a connector box under the cowl that is impossible to get to. Look along the front inside edge of the glass and you will see where it passes through the windshield gasket down into the cowling. After playing with it for a long time to try and preserve the connection we decided it wasn't worth the grief, broke the connection and will replace the antennae with an under the dash antennae box. Steps as follows:

1 - Glass out, sand paint back about 6 inches all around bubbled area to expose damage on the cowl and up and across the channel.

2 - Surface grind same area to remove surface rust and get to bare metal

3 - Wire brush area to remove all traces of rust and expose any areas of thin metal.

4 - Treat area with acid and let it penetrate overnight

5 - Spray an isolating and etching prime coat before using starting filler work

6 - Repair with several thin applications of curing filler with appropriate sanding between coats.

7 - Final filling, glazing and sandable prime followed by color

Final result was excellent and unless you knew what had been done, it was impossible where the work had been done. Cost: $ 650. panel & paint, $ 125.00 Glass out and in, OEM gasket $ 159.00





Rust area with glass out





Initial prep, sand paint, expose area





Chemical treatment





Final fill before paint





Color





Close p final surface

DobermanDad

I need to find a shop in Michigan that can do this for me. Not really a job I want to take on myself, because I'm so picky about how well it will look. I also have two small spot on the same area you guys described. What's interesting is that it was fixed about 10 years ago and still came back.

Also, I've used POR-15 on many motorcycle tanks. It works great.

GazC2

I have never come across a chemical treatment/rust buster etc that works long term, only real solution for me is to cut the metal out, and if you take the rev counter out you can get in to pull the aerial from the box.

DobermanDad

I got a feeling mine is gonna have to be cut out. Don't know until I start the project which won't be for awhile. So many other priorities at the moment. Still drives me nuts knowing it's there.

Vandit

I've got this same trouble area on my car. What's been keeping me from attacking it is the risk of breaking the glass which will easily double the budget for the repair job.

Every time I follow a semi-truck, I secretly hope they will fling a rock and break the glass so I can have a reason to run a windshield removal and replacement through insurance while I get the rust fixed.

abarthguy

The problem with most of these surface treatments is that there is usually more rust on the back of the panel that will continue to spread.

Cutting the metal back to virgin territory is the only long term solution.

Jjm4life

^^ echoing everyone else's sentiment. Cut it out and never have to worry about it again. I just had a small repair patch made for mine.

DobermanDad

Hope mine is that easy. My rust is very minimal. Two little bubble spots.

deadendd9009

Only small rust that you can see...wait until you remove the seal/windshield!