I just got a 91 RS on saturday. This has been a life long dream and its finally a reality. I noticed while cleaning the car out that there is rust in the spare tire compartment and the seam between the left rear quarter and the body is rusting. I treated it with ospho to kill the rust but I dont know how to go about repairing it. The same goes for the area around the t-tops. Not much rust but there is a little. Your help is appreicated.

using a wire brush on a drill is a good way to get rid of rust in a tight area. the best way to go is to try to get rid of all of the rust, after that bondo, primer, and paint. bondoglass is one of my favorites.

I thought bondo absorbs moisture? I'd probably try getting rid of all the rust, and then coat the seams with por-15. It will go like a ceramic finish and wont allow the area to breathe, therefor the rust will not return.

correct...bondo will absord moisture...and in general bondo just sucks (other much better fillers). For the best protection, you should grind off all the rust, then cover it w/ POR-15 (be sure to use their metal etch if its on smooth metal)... or just brush/scrape off all the loose rust, then cover it w/ POR-15.

My boss has turned me on to POR-15 and said it was the best stuff for rust. Question though, Can I put fiberglass over POR? There is a small hole in the bottom of my spare tire compartment (about 2"). I figured I would use the POR and then use fiberglass to cover the hole.

You could also try a body filler called "Dura Glass" it's water proof and its almost like metal. That's one body filler that I would put in a car where rust could or has started.

POR makes a patch kit that you could use to fix that hole.. Never tried it myself but i've seen some thumbs up from some chevelle owners.

Lead is the best way to fix something like that. I would try the por-15. They do make a thing that is like lead. Does anybody here know the name of it? Just don't cut any corners or you will be doing it again. Trust me I am!!!

hey i was just going to post a topic on this...my 86 ta has surface rust around the wheelwells and in a few other spots.I was told to sandblast the rust and the areas near the rust(cuz if you see rust its like at least 1"around that,under the paint where you cant see),then use epoxy primer?anybody hear of this stuff?if that stuff supposed to be thick enough to sand and then paint over??????
is this por 15 i keep hearing about thick enough that a guy could put on a coat of two on after sandblasting ,then sand it smooth,prime than paint the car,or is it super thin and still needs a layer of good auto body filler(notice i didnt say kmarts "bondo"line)
bodyguys out there let me know,i want to get my car painted and am wondering if i can save some $$$$$ on the bodywork end of it.thanks!!!!!

My boss used POR-15 on a car he restored. He said that it has the consistency of water but dries very hard. He was telling me today that he tried to scratch it with a key and had no luck. The web site makes it sound like the best thing on the planet for killing rust. I was thinking about doing all of the underside of the car from the front end components to the rear end.

You could either sandblast the rust, or if u dont have access to a blaster, just grind it off w/ a stone or wire wheel. I am currently doing a lot of body work on the jeep i'm restoring (http://mywebpages.comcast.net/BAK1/jeep) and I covered quite a few parts w/ POR-15, and so far I love it. The stuff is a little thicker than normal paint (I used the silver stuff... has metal filler in it)...you would then want to put their tie-coat primer over the POR-15 so make sure that any top coats you put on it would stick - - but depending on how much rust you have to blast away, you should get away w/o having to use a body filler.

If the rust has not eaten through the metal or made it weak (thin), the bestter treatment is to use a zinc rust treatment (I know it sounds like I pitching this like Mark Shields does Hooker exhaust ) such as OxiSolve or to remove the rust as best you can an coat it with a cold galvnizing compund such as ZRC.

"Bondo", the generic name deemed to all bodyfillers, as with most all bodyfillers, is made up alot of talc which is an excellent absorber of water. For light surface rust, there is no point in using body filler or any sort of fiberglass filler, most of all small pits can be filled after being treated with a high build or surfacer primer. There are also products such as galvaprime for treating bare metal surfaces to aid in rust prevention.

POR15 is closely the same thing as 'chassis black' paint or epoxy primer... it merely seals in rust, it doesn't get rid of it.

good point brought up by deadbird in that POR-15 doesn't eliminate the rust...only seals it and prevents it from rusting.

I haven't used Oxisolve or ZRC so I can't vouch for it, but using muriatic acid (hydrochloric acid) works great in removing rust. Might be cheaper than the name brand rust removers and probably will work just as well. The only hard part about using muriatic acid is that it takes a little while for it to work...and being a liquid it could get tricky to use in some spots - - spray bottle might work good. I used it on a few extremely rusted parts off my jeep (rear window latch, some bolts, etc..) and it removed all of the rust leaving the parts looking like new.

BAK.. I'll agree.. muratic acid does do a fine job of removing rust but, the problem is, if not neutralized, it will continue to eat the metal or, if washed and not treated almost immediatly, it metal will flash rust.
OxiSolve is cheap and works in a simlar fashin as muratic acid except OxiSolve leaves behind a zinc phosphorus (sp? I'm not that good) coating.. somewhat similar to galvanizing the metal, it is also reusable. ZRC is used alot in commercial applications, where galvanized metal has been welded/ground (effectively removing the galvanizing), as an equivilant to re-galvanizing the metal (thus the name cold galv. compund). I personally have used ZRC for over 5 years and, despite its cost ($8 a 8oz can aerosol can at a welder supply store here), works extremely well.