Help with rust on trunk lid!

NumericalIntegration · 05-24-2018, 01:57 PM

So I recently bought an 06 325i and there are a quite a bit of mechanical things that need doing, but for me those are no problem to do myself. What I need help and advice with is for some of the cosmetic things where I have much less expertise... So I noticed that on the lip of the trunk lid, by the rear window, there is rust/missing paint along a major portion of the lip.

View post on imgur.com

I figure that this is probably one cosmetic thing I should really take care of sooner rather than later. I'm wondering if the previous owner(s) maybe had a bike rack or something on the trunk, which might also explain some of the wear on the spoiler. For a short term fix I was thinking I could clean it up a bit and seal it with RTV or something to prevent further rust. But since this is much more than just a little paint chip with rust, does anyone have recommendations on more long term fixes?

Mark963 · 06-02-2018, 09:04 AM

Silicones of any sort really mess with painting - I wouldn't use that.

Over many years, I've fixed a number of scratches and chips that were down to the metal and I can at least say that what I did stopped the rust for at least several years. First I scrape the paint off around the chip until I get to clean looking metal. I have a very old bottle of "OxiSolv" zinc phosphate "Rust Remover" solution. When applied to rusted or bare metal, it fizzes slowly until the rust is gone. It leaves a layer of the zinc phosphate which seals in the metal, much like most original auto body preps. The bottle says to apply it for 30 minutes. Then I apply a thin layer of primer and whatever paint you can lay your hands on. I think the zinc phosphate solution is key to a long lasting repair.

Poking around a little, it looks like this is similar to Eastwood Fast Etch.
Ideal Prep for Painting and Powder Coating
Leaves Zinc Phosphate Coating
Promotes Adhesion and Prevents Rust

Good Luck!

05-24-2018, 01:57 PM	#1
NumericalIntegration New Member 1 Rep 17 Posts Drives: 2006 325i Join Date: May 2018 Location: St. Louis, MO iTrader: (0)	Help with rust on trunk lid! So I recently bought an 06 325i and there are a quite a bit of mechanical things that need doing, but for me those are no problem to do myself. What I need help and advice with is for some of the cosmetic things where I have much less expertise... So I noticed that on the lip of the trunk lid, by the rear window, there is rust/missing paint along a major portion of the lip. View post on imgur.com I figure that this is probably one cosmetic thing I should really take care of sooner rather than later. I'm wondering if the previous owner(s) maybe had a bike rack or something on the trunk, which might also explain some of the wear on the spoiler. For a short term fix I was thinking I could clean it up a bit and seal it with RTV or something to prevent further rust. But since this is much more than just a little paint chip with rust, does anyone have recommendations on more long term fixes?
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06-02-2018, 09:04 AM	#2
Mark963 Private 30 Rep 77 Posts Drives: 2011 328i Join Date: Jun 2018 Location: Iowa iTrader: (0) Garage List 2011 BMW 328 [0.00]	Silicones of any sort really mess with painting - I wouldn't use that. Over many years, I've fixed a number of scratches and chips that were down to the metal and I can at least say that what I did stopped the rust for at least several years. First I scrape the paint off around the chip until I get to clean looking metal. I have a very old bottle of "OxiSolv" zinc phosphate "Rust Remover" solution. When applied to rusted or bare metal, it fizzes slowly until the rust is gone. It leaves a layer of the zinc phosphate which seals in the metal, much like most original auto body preps. The bottle says to apply it for 30 minutes. Then I apply a thin layer of primer and whatever paint you can lay your hands on. I think the zinc phosphate solution is key to a long lasting repair. Poking around a little, it looks like this is similar to Eastwood Fast Etch. Ideal Prep for Painting and Powder Coating Leaves Zinc Phosphate Coating Promotes Adhesion and Prevents Rust Good Luck!
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