BSiegPaint

I've never had the opportunity to do much under my '71, but after a few winters on the North Coast, I figured an underbody clean-up was needed. Crawled under there and was astounded at the amount of surface rust on EVERYTHING. Now, I don't want a show car under there, but I need to stop this from going any further. Short of total removal and restoration, what have some of you used to remove surface rust? And I mean a good, crusty surface rust, not some powder that you can wipe off! I was already planning a nice coat or two of POR-15, but the rust I have is a little too rough. Should I just get going with a brass brush and sandpaper? Water blast and POR? Scotch Brite pads? Any success stories are welcomed - thanks!

verskel

There's a product I used on an old Camaro for turning "rust" into a paintable surface.... :yesnod:

However, it doesn't penetrate & you'll still need to sand / grind most of the rust flakes off.... also, keep in mind that rust is formed from iron & oxygen (iron-oxide) - so if you can effectively 'seal' the rust -it can't get any worse.
So, as a final step (on my old Camaro) - I 'glassed' in the surface before painting as a precaution (actually it was just the RESIN)... :D

Green76

BSiegPaint,
Get some wire brushes, the one you use by hand and also some that attaches to the electric drill motor in various sizes so you can get into those tight places. Also get some good goggles to protect your eyes.
POR-15 is what I used and is suposed to be the best but also buy what is called METAL READY it is a clear liquid you spray on the frame after you clean off all the rust, let it set for 20 minutes and then rince off with plenty of water, it will convert the rust into a white powder, after the frame is dry then paint with POR-15...
"POR-15" and "METAL READY" is manufactured by the same company just follow the instructions they give you. By the way the pot life of the POR-15 is short once you open the can it dries very fast in humid weather, I bought a 6 pack (4 oz. cans).
Ulf

73-454

Best way to deal with rust is , 1) get the underbody and the inside of the frame power washed, then scrape off as much of the rust as you can. 2) have the under body and inside of the frame oil spraded "engine oil is perfect" it will also lube all of the moving parts. This has worked on all of my cars. Forget painting the underbody waist of time and money. Re-spray the underbody every spring if you do this all of the moving parts will last for ever.

jerryjfunk

Hi,

For mine, I rented a sandblaster, and got almost all of the rust off, including the frame down to bare metal. I then put 2 coats of "rust converter" by Plastikote, which gave it a glazed look, and turned any small amount of rust into metal. From there, its primer and paint! :D

Jerry

BSiegPaint

Thanks everyone - you've given me a lot to think about. I was sold on the POR materials some time ago, but I will admit that I have heard of the oiling technique also. With the amount of rust I have, I really need to remove what is there. I hadn't heard of the Metal Ready material, so thanks for that. It's really a mess. And you know, you always want the quickest way out... :lol:

Tom454

http://www.por15.com/

Order their catalog... it has all sorts of goodies in it.

RE: the rust... if the car has seen a serious amount of the "salt belt", then you have cancer on the inside of the frame. Stick your finger in one of the holes on the bottom of the frame just in front of the rear tire. See how it feels on the inside. This will tell you how big of a project you have. If it feels smoth, then you're okay. If there are chunks of frame scaling off... then start to make funeral arrangements. :)

I knew a guy in Syracuse NY who welded all of the rocker panel openings shut (non-Corvette) and installed a bung & pipe plug. He then filled the rocker panels with used motor oil. The rocker panels outlasted the car (normally impossible in Syracuse). So... the "oil" idea definitely has merit.

For rust removal, I also use those "contractors" joint compound sanding sheets for rough surfaces... they let the crud fall through the mesh and don't load up on you. Speeds up the job quite a bit.

Tom

BSiegPaint

Thanks for the tips, Tom. I've only been in the rust belt for a few years, so this is all surface stuff, but the worst I've ever seen! I ordered the POR catalog and await its delivery. Good tip on the screen sanders - I've used them in plenty of house projects and have dozens in the garage.
:cheers: