Permatex Rust Converter or Picklex

[rancheroo]

Hey all, I'm working on a 66 Mustang and have a question about rust treatment. I'm currently working on the cowl seam under the hood, where the cowl, firewall and some other piece of metal come together. I spent a good bit of the day removing the seam sealer/filler that had been skimmed over this seam. There was a good bit of rust under the filler & I'm not going to split the cowl panel off to fix this. For the most part it's surface rust. No real cancer. I've gotten all of the rust off that I can with a wire wheel on a grinder.

My questions are:

Should I soak this area (three pieces of sheet metal) with Permatex rust treatment or use something like Picklex.

Also, should I reapply (goop it on heavy) some seam sealer or other filler once the rust has been treated/neutralized?

Thanks in advance, Rick

[Len]

I've never used Permatex so I can't compare it to other products. We've used several other products and found that Picklex does a MUCH better job of stabilizing rust. Most rust converters (including Picklex) need to be coated after treatment because the converters aren't water proof so you need primer and paint or something that will be a good barrier against moisture.

[e-tek]

I'd use any Phosphoric Acid treatment (Picklex, Metal Ready from POR15, OSPHO, Naval Jelly, etc), then wipe it off with water and dry it well with compressed air. After that, I'd use POR 15, then seam sealer before priming and painting the area. I've heard Permatex can cause adhesion issues for some paints.

When applying seam sealer, I always tape off both sides to contain it and make it look nice and straight.

[cstephl]

I have used the Permatex rust converter and also had adhesion problems. I had some small areas where I had sanded w/ 80 grit down to bare steel, applied the Permatex over the rust pits and surrounding bare steel, then epoxy primed and topcoated. I found that masking tape would pull the permatex/paint off of the bare metal. After finding this problem I sanded all the Permatex off of the bare steel, just leaving it in the rust pits prior to epoxy priming. That seemed to work OK, however I will use a different rust converter in the future.

[66aCuda]

I too have had problems with the Permatex/NAPA Rust converters. No problems with the paint sticking but the finish can be easy to remove.
Frank