If you want it to look great, take it to a pro. I'd guess off the top of my head that it'll be about $750-ish to get that taken care of properly. Every shop will give you a different estimate.
I'd try to get a start on this before they get worse. You can't really screw up a rust repair - it's the bodywork that comes later that's easy to mess up. That one patch in front of the rear wheel is pretty ugly but the rest should be easy to stabilize.
I normally use a few different techniques. First is the convert-seal-prime-paint method. Next is the remove-replace-prime-seal-paint method. Depends on damage. BTW, Rustoleum "Sunrise Red" isn't a bad match for the BMW Brilliantrot.
First, I'd pull the interior panel and trim strips to see how deep the rust goes. If it's not serious penetrative rust I'll toss one of those 3M plastic round brushes in my drill & grind away until I get to clean metal. That is easy with paint but difficult with BMW's undercoating.
Second, I put a few coats of rust converter on all the bare steel. It'll also eliminate many rust pockmarks. Permatex sells a nice spray-on version, but I usually buy the little pint tins. Should be mostly phosphoric acid regardless of brand. Follow the directions as indicated...usually don't put it on under 60degF, light coats every ten minutes, etc.
Third, I use a very durable sealant/primer product called POR-15. You've likely heard of it. It's fairly expensive but worth it IMHO. I try to use thin coats but it tends to go on fairly thick and dribble. Use a foam wedge or disposable brush to apply. That will take a few days to cure, but they claim that water isn't a problem (in fact it may help in hardening it). It has a very good reputation from what I've heard. Use a sheet of saran wrap under the lid when you're done using POR-15 - otherwise the first time you close that can will be the last time you open it!
Otherwise you're into the cut & paste method. For that I find a good donor or order rust repair panels. Many salvage yards will let you order 'cuts' or parts of salvage car bodies. Unfortunately, all e30's tend to rust in the same spots. I don't weld but I've heard that Eastwood 2-part slow cure seam epoxy and an air flanger are a great team. Then proceed as above; rust converter, Por-15, sandable primer & finally a few topcoats of Rustoleum sunrise red laquer.
Topic: Question about rust (Read 4337 times)