Rust on my Thing

April 18, 2009 2:14 PM

I need advice on taking care of rust on a Volkswagen!

I just bought my dad's 1974 Volkswagen Thing. It used to be cherry, but he let it go to hell a few years ago when he started feeling his age and wanted the comfort of a Land Rover. So I took it off his hands, and I will restore it eventually, but in the meantime, how can I affordably get rid of the rust on the body and trim that has built up, without getting a body shop involved (I'll worry about paint, etc. later)? It's pretty bad in some places.

posted by Brocktoon to sports, hobbies, & recreation (11 comments total)

The only way to do this is to sand it down and paint it....
posted by HuronBob at 2:23 PM on April 18

My dad used to have a bit of a VW...problem. He started out sanding, priming and bondo-ing the Beetles, but later learned to weld on the Thing and a bus. He'd just cut out the rusty part and weld a new bit in. He was REALLY into doing that for a while. Also, there was a rusty hole on the hood - he stuck a volkswagen "Turbocharged" metal emblem in there to cover it up. There was also an interior hole - decorative cigarette lighter! I don't know how affordable it is to learn to weld, though! :)
posted by artychoke at 2:36 PM on April 18

Huron, I just want to keep it from spreading. I don't want to just slap some paint on it and say "good". Can you be more specific?
posted by Brocktoon at 3:01 PM on April 18

Let me introduce you to The Samba. Also, meet your new friend POR 15.
posted by mmdei at 3:02 PM on April 18

Brocktoon... To deal with rust you need to remove it, down to bare metal (and, if it is rusted through, do some welding)... Once it is removed you'll need to put something on the metal, or it will just rust again... Primer will do for a while (if you don't care how it looks), but to really protect it, you'll need a good paint job...

you can always go back later and put a quality paint job on it... you get what you pay for...
posted by HuronBob at 3:37 PM on April 18

Phosphoric acid to neutralize the rust, then POR 15, then paint it.
posted by Floydd at 4:52 PM on April 18 [1 favorite]

THE fundamental rule. You *must* get rid of all of the Iron Oxide, then rebuild the surface. H₃PO₄ will convert Fe₂O₃ to FePO₄, but you then have to scrub off all of that before you start to repair. Most body specialists don't even try, they grind down to bare metal and rebuild from there.

Or they don't try, they rip out a damaged panel and replace it with NOS. However, this almost always entails some metalwork to make it fit right. Small imperfection were commonly leaded -- lead was melted and the repair filed down to make a smooth surface.

It really is a specialized job. If you're looking just to stop the damage right now, you can grind the rust out and hit with POR 15, then primer -- but you must get all of it, or it'll just keep rusting away. Worst is perforations, because then there's rust inside the panel, and it's a pain to make sure you've gotten all of that.
posted by eriko at 6:21 PM on April 18

Get sandpaper or a sanding disk, grind the rust completely off, spray on primer and then a finish coat. Lots of sites describe how.

There's also a product that comes in a spray bottle that you can get at auto stores (Kragen, Finishmaster) that claims to turn rust into a black primer-like surface that you can then paint.
posted by zippy at 8:11 PM on April 18

Sand and grind, like everyone says. Then roll. I've done this and was super happy with the result. will send link to photos via memail if anyone wants to see.

A Dodge Dart. Also, here's an orange bug project on flickr.

Have fun
posted by auntbunny at 9:24 PM on April 18

OK ya, I'm looking for something temporary. Undoubtedly welding will need to take place, which I will probably not be doing myself. But that's in the future. In fact after looking at it again this afternoon, the windshield will probably need to be replaced completely. And I'm thinking primer at this point looks a lot better than flaky rust. Pretty much anything would look better. But I'm not concerned too much right now about looks (I can't afford to be).
posted by Brocktoon at 11:52 PM on April 18

If you can only do one thing right now start with the phosphoric acid. You can buy it along with some rubber gloves, safety goggles, and a brush to apply it with at the hardware store. Get a metal brush too and scrape off what you can of the flaky rust first.

It's fast to apply and when I've used it I haven't seen the rust spread over time.
posted by yohko at 2:29 PM on April 22