I recently bought my first car - a used '98 Jetta. It’s in pretty good condition, but there are some rust spots - a larger one under the door and a couple smaller ones - that I’d like to fix. There also seems to be a little corrosion underneath the car, I’m guessing from snowy conditions. What would you suggest is the best way to get rid of the rust? Are there any products I should use or do I just need to sand?
Frankly, sanding/grinding is best.
Words Of Caution . . . Sometimes Amateur Spot Rust Repair Can Look Worse Than The Rust Spot.
Practice on the lowest, hardest to notice spots first and see how it looks before you move up to eye level.
There’s a reason why professionals paint entire panels to fix a small spot and then they usually even blend the paint by painting parts of adjacent panels, but you don’t want to go there, trust me.
Do a search on the internet or get a book for some ideas before you try it at home. You’ll need the exact touch-up paint color specifically sold for a 98 Jetta in your color.
Oh, and congratulations on your first car ! I think everyone will always remember their first car. Good luck and have fun with it.
CSA
The only way to permanently repair rust is to grind or sand it down to bare metal, fill where applicable, prime and paint. Some of yours may be coming from inside, and in those cases you should remove all you can, fill, grind & sand to shape, prime and paint.
A book on autobody repair may be a big help to you. I’d highly recommend it. You can pick one up at any bookstore.
Dupont makes a rust binding paint that I have had some luck with. It is black. If you just want to stop surface rust it is ok. If you want to get to any deeper damage, and you care about appearance, do as these other guys say, grind it off, fill it with body putty, sand it smooth, re-fill with the surface putty, sand down to an ultra fine grit, then spray with a filler/primer, and when that is cured, not just dry, paint with the mfg. recommended color matching paint. dont expect it to match exactly. When that cures, wax it or use whatever other kind of final treatment you like. Oh, but if the area has a clear coat on it, that may create other complications, what do you other guys say, complications, yes or no?
Rust is tricky. It sounds like your 12 year old car has been spending some time in areas that are salted for winter driving. First you need to determine if this is “surface rust” or something deeper.
Surface rust is a spot where paint has chipped off and some rust starts on top of the metal where it is not protected by the paint. It is pretty easily sanded down to bear metal, primed and then repainted. The quality of the priming and painting vary greatly with the skill of the painter. Most jobs pass the 10 foot test, but a close look will show flaws typical of repairs done at home.
What you may have is rust that has penetrated the metal from the underside and has now worked its way through all the metal and is bubbling up the paint on the top surface. Here when you start sanding you are going to find the spot gets bigger and bigger as you sand deeper into the spot. This is going to take more to fix. You’ll have to remove all the decayed and rotted metal and that will leave a pretty big hole. You can fill this with bondo, or a mesh covered with bondo or fiberglass, or best yet have some new metal formed and welded into place. Then it all gets smoothed out, primed and painted. This paint job covers a bigger area and might need an experienced body shop paint job to look decent.
Don’t be too surprised if your minor rust spot repair turns into a major project.