Getting rid of Rust

[Kevo]

Hey whats up fellas. I got a few questions that i need straightened up, so if anyone could help that would be awesome.
I am doing body work on a 68 dart, and i have sanded the metal down to strip out the rust. I have DX-579 to get rid of the rust, and DX -520 to put down a zinc layer , but i have a few other questions. On the inside floorboards, i need to get rid of the rust before i weld, i know the dx-520 creates a layer of zinc, which will make me sick if i weld it, but does dx-579 create a layer of zinc or no? Is it safe for me to weld after using dx-579?
Also, if i sand down areas that are not rusted out, can i just shoot it with self etching primer and then layer it with high build primer? or do i need to treat it first even though there isn't rust?
I figured i would get the help of someone who knows what they are doing before i go and get ahead of myself. Any info on it is greatly appreciated.

 

[75Sport]

Bump back up. I'm sure you'll get some answers.

 

[inkjunkie]

For what it is worth you can sand til the cows come home, there will be rust in the pores of the metal. My car had hours of preventative measures thrown at it prior to painting in an attempt to avoid putting 1/4 patches on it. A few weeks after it was painted a very small bubble appeared. With how little room there is between the 1/4's and extensions there is no way to effectively treat that area to stop the rust, if it is already present. Car is going back to the body guy to replace the lower quarters and trunk extensions. I know I did not answer your question but.......

 

[dodge freak]

yep, rusted metal needs to be replaced for the longest lasting repair

Or you could just slap some plastic-rubber down low like these new cars have :banghead: