what method to remove rust ?

[chimp koose]

I am removing the rust under the cowl in my T coupe before I weld in my recessed firewall as access will be minimal afterward .I will por 15 the area as well as the entire interior surfaces of the car at some time before I am finished . So far I have had 36 grit sanding discs on an angle drive die grinder. The discs don't last long and the rust starts to just shine when the disc plugs up. If I use 80 grit emery cloth by hand the rust comes off as fast but again the cloth gets used up pretty quick . Is there a more efficient way ? I am trying to do this without chemicals as I don't want chemical leeching later on . Not real keen on blasting either . what to do ? how clean is clean enough as far as getting all the rust? thanks in advance for your replies.

[papastoyss]

I use a cup  knotted type wire brush (4" dia.) on a HF angle grinder. It'll make the rust fly.If you are using Por 15 scale rust removal is all that is necessary if I understand correctly.

[enjenjo]

I use a cup  knotted type wire brush (4" dia.) on a HF angle grinder. It'll make the rust fly.If you are using Por 15 scale rust removal is all that is necessary if I understand correctly.

Yup, tight rust is fine.

[chimp koose]

That is what I had read about por 15 that you paint it right over firmly attached rust but that just seems so weird to me. All my life we have attacked rust to get rid of it so it wont come back , it seems weird to be able to just paint over it and forget it. If I want to overcoat the por with another product I am supposed to spray a primer over the por before it dries ,am I correct? I would like to eventually overcoat with the home made lizard skin , then either the aluminum skinned roof flashing or the foil wrapped bubble wrap ,or even both.

[kb426]

CK, the low e brand insulation is the best I have used. It's less than 1/4" in thickness and has foil on both sides. I use upholstery spray adhesive and put it everywhere.  
http://www.lobucrod.com

[idrivejunk]

All my life we have attacked rust to get rid of it so it wont come back , it seems weird to be able to just paint over it and forget it.

Amen to that. Never deny your spirit.

I like to use these but they are also available in the Roloc style. They are just right to walk the line between rust and steel removal with light pitting. There is a softer black version if your metal is very thin and precious, they wear faster but reach deeper into pits and are gentler on steel. Follow with quality one step rust converter per instructions or repeat until satisfied, then sand with 80 on a DA or orbital angle sander with small head if space is tight. Then treat as usual with a 2K direct-to-metal primer and exterior quality topcoat material. Just my experience with no come-backs!

[enjenjo]

The theory of Por 15 application.

It is for all practical purposes Super Glue, with a pigment in it. It cures by extracting moisture from the air, and the rust. So by removing all but the tight rust, which is really stuck good, the Por 15 sticks to the rust, and the rust sticks to the steel. You apply a second coat within 24 hours to make sure you didn't miss any pin holes. I have a car I convinced a local body shop to do that way 12 years ago, and it shows no sign of rust, and it's spent some time stored outdoors.

If you are going to paint over it, you should at least prime it within 24 hours, or scuff it good before priming. Without scuffing, nothing will adhere to the surface, including more Por 15.

Por 15 will not stick to clean metal unless you etch the metal before you apply it. At that point, you might as well use an etch primer and skip the Por 15.

It is a Isocyanate paint, so when brushing, lots of ventilation, if spraying use a positive external air supply.

[40_Tudor]

Picked up a rear fender at the Springfield swap meet a few weeks ago and asked some coworkers if they recommended a media blaster locally. One guy had a friend that has a powder coating shop and cleanse part, body, frames in a big oven. Bakes off paint, putty rust and all. He took it to him and just got it back. It does a really nice job. His oven is big enough to put a car in. 2000 degrees no oxygen, all they do afterword is power wash it. I think the shop is in Indiana some where.

[kb426]

That oven sounds great. I'd like to see some before and after pics.

[chimp koose]

wonder how well it would clean a corvette!

[40_Tudor]

I didn't take a picture of the before but I can take one of the after and post it maybe tomorrow. Just picture all rusty scale on the backside and some rust and old blue paint on the outside.

[40_Tudor]

Here's the rear fender after baking at 2000 deg. in an oven, no oxygen. Before, old paint and some rust on the outside and flaky rust no paint on the back side. It's been sitting on the shelf for a couple of weeks, I need to get primer sealer on it soon.

[39deluxe]

Very interesting. They must seal the oven then purge the atmosphere with nitrogen before heating. Is there any warpage or isn't 2000* hot enough.

Tom