Bubble rust above fuel door? - PeachParts Mercedes-Benz Forum

cewyattjr · #1 10-03-2010, 12:07 PM

See lovely photo, attached.

I wish I knew how to stop this? What would cause it, moisture from inside the cabin? Best way to treat?

Thanks,

Chuck

Matt L · #2 10-03-2010, 12:12 PM

It's moisture trapped under the trim piece. You'll need to remove that to fix the rust underneath.

cewyattjr · #3 10-03-2010, 12:26 PM

Thanks, Matt! I wonder what the best way is to remove that, it just looks like a metal piece with a rubber seal around it. Would it just pop-off with a screw driver?

charmalu · #4 10-03-2010, 12:28 PM

That isn`t surface rust that is bad rust, been working for a while.

the grey center trim piece is just friction fit in place. the back side has 2 tits that fit into a plastic insert. The piece is aluminum and can bend easily. so from the rear edge insert something thin to pry it up and work along the seam towarts the front. hold the trim piece so it doesn`t curl.

as you work along the tits will pull out, then pull it towards the rear. It fits under the raingutter edge.
there are 2 phillip screws that hold the aluminum frame to the car.

Charlie

Matt L · #5 10-03-2010, 12:33 PM

The trim will probably come off a lot easier now than when the car was new. The rust likely originates at the holes in the panel.

Biodiesel300TD · #6 10-03-2010, 12:35 PM

Quote:

Originally Posted by charmalu

That isn`t surface rust that is bad rust, been working for a while.

the grey center trim piece is just friction fit in place. the back side has 2 tits that fit into a plastic insert. The piece is aluminum and can bend easily. so from the rear edge insert something thin to pry it up and work along the seam towarts the front. hold the trim piece so it doesn`t curl.

as you work along the tits will pull out, then pull it towards the rear. It fits under the raingutter edge.
there are 2 phillip screws that hold the aluminum frame to the car.

Charlie

I was trying to figure out how to get mine off when I put in a new rear window seal. But I didn't spend too much time on it. But now I know how to get it done. Thanks Charlie.

cewyattjr · #7 10-03-2010, 02:09 PM

Thanks again. I have that trim piece popped off now. Looks like water gets in the holes. I can scrape and treat all the undertrim with POR-15. What about those bubble things, I guess I have to bite the bullet and knock those off, sand, and treat?

I'm afraid that it is the BODY of this car that will be the death of it. Just put in 5 new glow plugs yesterday and a new thermostat, and she starts and runs great.

charmalu · #8 10-03-2010, 02:35 PM

Well those bubble things is rust under the paint. when you scrape through that, you may find it has eaten through the sheet metal.

If i was fixing that on my car, I would clean it to degrease, dewax the area of silicone etc.... then use spme paint stripper to clean back to good metal.
then use POR metal Ready to etch the metal and eat as much of the rust as possible. then cover with the POR paint.

POR has some very thin Fiberglass cloth. cut it to fit over any pin holes, and saurate with the POR paint. they also have a seam sealer which is the POR paint in a paste form. I use an acid brush to smear the stuff in good.

Forget about it being pretty etc.... with winter coming on, it needs to be sealed up. might want to check the other side too. HMMM, wonder what lurks under the rear glass seal?

Remember, rust never sleeps. I don`t believe this thing as, "surface rust". you have rust, or you don`t.

Glad to be of service, Andrew

.

I bent mine trying to get them off a few years ago. so PNP came to the rescue. trouble was my car is silver, and I found a brown and creame color one. so used paint stripper and polished them. they shine real nice.

Charlie

cewyattjr · #9 10-03-2010, 02:44 PM

Charlie, sorry if I missed the obvious, what's PNP?

-Chuck

Brandon_SLC · #10 10-03-2010, 03:58 PM

Quote:

Originally Posted by cewyattjr

Charlie, sorry if I missed the obvious, what's PNP?

-Chuck

Pick and Pull. Self service junkyard

cewyattjr · #11 10-03-2010, 04:36 PM

Thanks Brandon. Just got back from scraping that puppy down the the metal. Sprayed with Metal Ready. Not sure if I have to order POR-15, that stuff doesn't seem to keep once you open it. I've got this Rust Converter goop, but not sure that it is near as good. Still better than leaving it to get eaten away!

vstech · #12 10-03-2010, 06:51 PM

por15 keeps fine if you seal it with seran wrap when you put the top back on.
the tiny kit works for a lot of projects.

fruitcakesa · #13 10-03-2010, 08:08 PM

Quote:

Originally Posted by cewyattjr

Thanks Brandon. Just got back from scraping that puppy down the the metal. Sprayed with Metal Ready. Not sure if I have to order POR-15, that stuff doesn't seem to keep once you open it. I've got this Rust Converter goop, but not sure that it is near as good. Still better than leaving it to get eaten away!

I only put what I need in a separate cup, clean the can rim and reseal immediately.

charmalu · #14 10-03-2010, 09:45 PM

Quote:

Originally Posted by vstech

por15 keeps fine if you seal it with seran wrap when you put the top back on.
the tiny kit works for a lot of projects.

Turn the can upside down to keep any air out. I have had cans set up even using the seran wrap and having them upright. The POR distributor in Sacramento told me to turn them, and it works. also, don`t use a plastic bottle, can etc... to store the paint in. It will still set up, for some reason the plastic will let air in. It is really the moisture that sets up the paint.

10 yrs ago they had the kits with the small containers of paint in a plastic can. they went to the small metal cans for that reason.

It`s amazing how far one of those little cans cover. I think they are 4oz?

Charlie

charmalu · #15 10-03-2010, 10:02 PM

Quote:

Originally Posted by fruitcakesa

I only put what I need in a separate cup, clean the can rim and reseal immediately.

X-2. The longer the can remains open, the more time it is exposed to moisture, and this activates the paint to cure in the can.

Dip out what you need, and close it up. the seran wrap helps to seal the can when the lid is down tight. With out using the seran wrap, and just sealing the lid back on. any paint in the groove will weld the lid to the can, and you will destroy the can trying to get it off.

I have 2 8oz cans, one black and with the silver paint. i just pounded the lid back on. the paint started to cure in the can, and chemical reaction caused the can to swell up. the bottom of the can looks like it could blow off.
this is from my early day of using POR before I learned the tricks.

Be sure to wear some rubber gloves, or you will wear the paint on you skin for a while.

Charlie