Is it OK to use POR-15 over a rust converter?

[83imp]

After I went to the bodyshop today and found out that the guy would let me use his booth for no charge this summer, we then got on the topic of fixing rusted panels and POR-15.  Although he had good things to say about the POR-15, he said that I should really think about using a seperate rust converter prior to using the POR-15.  He mentioned a spraybomb converter that chemically converts the rust into something else.  I know what he's talking about and I think it normally turns the rust black, but is this really needed?  Will the POR-15 adhere to it OK?  Any other thoughts?

I know he's a "professional" body guy and he said this is what has worked best in his scenarios in the shop, but it goes against the instructions provided by POR-15 so I'm just curious.

[jeff_past]

I was under the impression that POR-15 also changed rust into an inert material, that way you could just clean the rust and apply it right over without using a rust converter first. 

Check this tech article, it says the same thing (might not make it true tho  )
http://moparmusclemagazine.com/techarticles/mopp_0506_panel_replace/index1.html

[ski]

The POR-15 I've used has been a three step process.  First is a cleaning solution called " marine clean" second is the converter/etcher called "metal ready" and third is the top coat.  It even says on the instructions that you don't have to usr their topcoat and I usually don't.  Any good paint will work.  I'd use their metal ready if you're going to use the POR-15 topcoat.  It come in big pump spray bottles. 

http://por15.com/

[ski]

By the way that's not to say you can't just paint the POR-15 topcaot ovet the brushed rust either.  They do advertise that usage.

[rumblefish]

POR 15's Marine clean is simply a water based cleaner, you can use any WATER based cleaner (NOT the popular wax and adhisive cleaner body shops use), metal redy is a rust converter much like MARHyde rust converter. but I have even used naval jelly in this step. main thing is CLEAN (with no residue), convert to iron phosphate, seal with POR 15. if you do it right the metal will look powder coated and the finish will be virtually inpenitrible. 

[BOTTLE-FED_CUDA]

The stuff you body shop guy is talking about is Extend it has to be top coated; I would stay with one product through out the process (POR-15 and metal ready) so you don't have any adverse reactions between the two different products. IMO Extend sucks compared to POR-15.
Ritchie

[AdamR]

POR 15 stands for Paint Over Rust, it doesnt stick well otherwise.

[azz7772]

i use rust bullet it is the best

http://www.rust-bullet.com/

[383 DART]

I HAVE USED EXTENED & IT WAS CRAP.I HAVE USED POR 15 ON MY LIL RED EXPRESS FRAME OFF RESTO.IT IS GOING ON 3 YRS. & LOOK'S GOOD.I ALSO SPRAYED IT ON TOP OF THE FACTORY PAINT UNDER MY 88 PLY POLICE CAR.2ND WINTER & LOOK'S GREAT.POR 15 STOPS THE RUST FROM SPREADING.IT IF THE RUST CAN'T BREATHE IT CAN'T SPREAD.