best rust converter?

[DusterDaddy]

I have a 74 Duster factory 318/904/8.25
The motor was seized when I bought it and the trans housing had a nasty split in the side.

So for the most part I am left with a rusty roller.

Since I am going to strip the car to the unibody and rebuild it, After I strip it and wire brush the unibody, what is the best rust converter to use before epoxy primer?

Also wondering if an economy wire feed mig welder will be good for welding in patch panels?

 

[C130 Chief]

Most of the "rust converters" or "rust dissolvers" are phosphoric acid based, and work similarly. Check with your local paint and body supply store.

As for MIG welders, look around. A low time used name brand unit probably wont cost much more than a Harbor Fright cheapie.

 

[ef8340]

depending on the amount of rust might be a good idea to have it sand blasted then the rusted areas treated with the acid. if your planning on replacing the qtrs. cut them off and get the inner structure real clean. same goes for the inside of the frame rails cut out the bad and blast then seal. as far as welders go i'd get one with a bottle not a flux core wire feed you'll have a lot better results and wont come back to haunt you. wire brushing the underneath will only smear the undercoating around if it has it. if it does spend some time with a propane torch and a scrapper. I personally before attacking the car with cut off wheels and grinders would remove the undercoating 1st.atleast around the areas you plan on keeping. good results are mostly achieved by time and proper prepping

 

[Woods74]

I'd like to think if you strip and clean with a wire wheel it, wash it really good, the epoxy will work, it isn't a wuss. It's epoxy. For welders; Look at my build and decide. Did the whole thing with a HF flux welder. They don't like long flat areas, besides that your golden.

PS: Rustoleum bar-b-q paint works great as a weld thru primer.

 

[MoparMic]

I bought Por15 Prep Ready but its the same as Ospho. I have used Ospho in the past on parts that are years old with no rust breakouts

 

[68gtxman]

I swear by POR 15 paint, but either spray on your primer while it is still tacky or use their self etching primer over it after its cured. Personally, I always spray the primer on while it's tacky and have always had great results.

Smaller areas of rust, I use the Mar-Hide rust converter. It comes in a spray can and is fast and easy to use. Any paint or primer sticks to it when it's dry.

I have a HF el cheapo wire feed welder myself but haven't tried it on body panels yet. Great for everything I've used it on so far.

 

[BillGrissom]

I like Rust Destroyer because it converts rust, etches bare metal, and is good to 800 F, so holds up around exhaust pipes. ~$22 quart cans or $12 spray cans at Home Depot. I give it at least a week to cure, otherwise it can wrinkle the top coat.

 

[dodgecity]

I like picklex after blasting. Then a non acid based epoxy like matrix or Kirker.

 

[mopar79sean]

I would also like to add I am having very good luck with a harbor freight heat gun for removing undercoating. I've been under the dart cleaning it all up the past few days. I'm glad you asked about the rust converter as it is also a question of mine.