Restoring Rain Gutter Strips

Alan_uk

A2OC Donor
I've been getting the car ready for the Welsh trip and decided to at last sort out the Rain Gutter Strips which look awful. It was sunny this afternoon and the car got quite hot, so ideal time to remove the strips as they are more flexible than when cold.

00 Section of the gutter strips_s.jpg click photo to enlarge

Not only has the lacquer gone but the paint has in places as well (the yellow is the natural plastic colour).

I made a wooded wedge to prise the strips out and tapped it with a small hammer. Take care get under the rubber mounting strip rather than hammer into it:

01 Wooden wedge_s.jpg

Once levered up the boot can be closed and then push the wedge along by hand taking care not to bend too much.

02 Pushing the wedge along.jpg

Here's an empty channel with crud, especially at each end.

03 Empty gutter with crud_s.jpg

They were clean out with meths using a toothbrush and then waxed to remove black stains and to protect and as a precaution put blu-tak put at the ends to stop rain going under the rear lining (but shouldn't be necessary). One can see the neat welding done by the Audi robots.

04 Cleaned gutter with Blu-tak_s.jpg

continues
 
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I then cleaned the rubber strips with meths using toothbrush. Note that I had not separated the plastic and rubber parts of the strip as together they are more ridged. I did this on a large sheet of cardboard to protect the strips from deep scratches as I was doing this on the ground as they are so long. The ends needs a lot of scrubbing and scrapping with the finger nails to get the crud off. Maybe they were glued in originally. Once cleaned the plastic and rubber can be separated easily.

This photo shows the opposite ends of the rubber strip (click to enlarge). Note they are different and also note the groove (the dark line) for the plastic strip T section is offset. I forgot to note which end is at the front of the car, but the strips have a natural curve and the ends are not square but acute so hopefully I can figure it out on reassembly. They are beginning to perish. I don't know if they can be bought separately from the plastic strip. Anyway I've decided to reuse them.

05 Opposite ends of the rubber strips_s.jpg

Here are the opposite ends of the plastic strip which is T in profile and again the T is offset.

06 Opposite ends of the plastic strips_s.jpg


Tomorrow hopefully I can rub down and paint.
 
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Final Steps

Weather delayed progress but now it's finished.

Primer

First I applied a thin coat of primer to the strips by holding the can about 9 inches, as I read this is best to create an initial bonding. This was followed by 4 full coats of primer each applied as soon as the first coat went matt (i.e. touch dry, though I didn't tempt fate by actually touching). These were done about 6 inches away.

All coats were done in a single sweep from one end to the other, keeping a constant distance from the curved strips and a constant speed. i.e. no sweeping the aerosol can back and forth. For the thins coats I moved faster.

As the strips were curved and kept wanting to twist on their side I bluetak them to a block (see photo) but one kept springing off. So for the base and lacquer I did them one at a time gripping one end of the foot of the T strips in the work bench (see photo).

07 Undercoat lr.jpg

Base

Similarly a thin coat of base followed by 4 coats of base. Halfway through the last coat on the 2nd strip the aerosol can splutter and left splodges. A quick shake of the can allowed me to finish OK but I had this bad spot. After letting dry (gently aided by a hair drier) I gently rubbed down with 2000 wet and dry with plenty of water applied from a spray bottle. Another good shake of the can and I managed to get a good flow of paint to complete. Phew!

Anyone following this is advised to get 2 cans of paint. i read one comment that the 1st third and last third parts of an aerosol can are useless.

08 Top coat lr.jpg

Lacquer

And again, a thin coat of lacquer and 4 fuller coats. Then the strips were left to dry for a couple of days.

Rubber Strips

Meanwhile the rubber strips were cleaned with meths and a toothbrush and then treated to a good application of Nextzett Gummi Pflege. This really made the strips soft.

Reassembly

Using white cotton gloves, just like the Audi production workers, I reinserted the finished plastic strips into the rubber strips, starting with the closed end. As the strips beds in correctly there is a nice click sound.

Using the gloves the strips were reinserted in the car on a warm day, starting at the closed end at the front. The strips are handed nearside and offside, but it's obvious which goes on each side by looking at the acute angle of each end.

After a week they were waxed.

11 Waxed lr.jpg
 
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Alan_uk i followed all of your steps in this how-to guide. Just finished with painting/spraying. First i clean with tooth brush, dry and clean with nitro thinner and soft cloth. Then passed with 600 sand paper and clean again with nitro thinner and soft cloth. Than I put 4 layers of paint in 10" intervals. As my color is brilliant black LY9B, i dont need to apply clear coat. In any case i spent one full can off spray - 400ml.
Here are the results. The surface of fresh paint is a bit like orange skin. Just a little bit. I think to pass with 1500/2000/2500 sanding paper (wet) and polish after. But i must wait a couple of days first. Tell me what do you think about results? Cheers, Andrej
 

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Looks a good shine Andrej, plenty of reflections. I thought clear coat gives protection against sun and ultraviolet rays and oxidation.
 
I thought clear coat gives protection against sun and ultraviolet rays and oxidation.
Me too. I thought every paint nowdays has a layer of clearcoat. But when buying the paint, seller told me that brilliant black (LY9B) is not metallic paint, so no clearcoat is applied. He also said, that this is the reason why non-metallic paints are less expensive. Makes sense. He also mentioned, that metallic paints, when base (paint) is applied the dry surface is very matte, and gets shinny effect only after clearcoat applied. Also this makes sense.
In any case, I did a test before and painted to pieces of metal, one with clear coat, one without. After polishing there were no visual differences between them.
Cheers, Andrej
 
Best to spray horizontally, gives the spray pattern the nozzle was designed to deliver.
Spraying vertically, especially downwards, means the tiny drop of paint coalesce to form larger drops, which can spoil the finish.
Several light coats of clear lacquer must be added. Rattle can paint is not designed to be flatted. Just light coat on coat.
Mac.
 
Done.
It's been only 24hrs since last layer of paint (i decide not to put clear coat after all), so it was quite hard to put the rain gutter back to its place, as some pressing is needed and the paint is still soft.. I was working with soapy water to reinsert the strips back to place, and it was going smooth. Here are the results;
 

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