does this rust start from the inside or outside??

[MadOgre]

I applied POR15 to bare metal with no rust! Did the metal prep process they want and just primered and painted it.

I had a few dents that I banged out before painting but that's it. There is no Body Filler on my panels.

But I planned on using filler on top of the POR15 for my next truck which has a few problem spots.

 

[MadOgre]

I don't cover over rust! LOL that would be insanity! Rust gets cut out not painted over. Even my frames get sand blasted before POR15ing them!

Even though POR15 claims you can. I wont!

Not to mention it would look like complete crap!

 

[smoothandlow84]

And many magnets will stick even if the filler is 1/4 inch thick. One of those floppy refrigerator magnets work the best for finding filler.

I should have gone into more detail regarding my magnet technique. My magnet is a thin sheet type. Its comparible to the type used for signs attached to cars for advertisement. Very thin, almost as thin as the fridge "flopp" ones. Rare earth magnets definately stick too much to,work when trying to detect bondo on truck or car panels. Tapping and a good ear also works. Im not in the rust belt so not very familiar with the por 15 product. I always body fill over bare metal and body filler doesn't cause rust, applying the product incorrectly will. Thats just an absurd statement ( got a good laugh out of it). Leading can be accomplished on the thinner gauged sheetmetal used up to the late 80's with great results as long as you apply it correctly just like anything else. Any sheetmetal after 1990...yeah I wouldn't suggest wasting time with that endeavor. Replacement body panels are the best option. Reading up on the por15, I would only use that on a frame and not on a panel, but that's just me personally. I'm not in the rust belt, so in a desperate attempt to prevent rust, I can understand why you guys do everything possible,to prevent metal cancer wherever it may pop up.

 

[MadOgre]

I should have gone into more detail regarding my magnet technique. My magnet is a thin sheet type. Its comparible to the type used for signs attached to cars for advertisement. Very thin, almost as thin as the fridge "flopp" ones. Rare earth magnets definately stick too much to,work when trying to detect bondo on truck or car panels. Tapping and a good ear also works. Im not in the rust belt so not very familiar with the por 15 product. I always body fill over bare metal and body filler doesn't cause rust, applying the product incorrectly will. Thats just an absurd statement ( got a good laugh out of it). Leading can be accomplished on the thinner gauged sheetmetal used up to the late 80's with great results as long as you apply it correctly just like anything else. Any sheetmetal after 1990...yeah I wouldn't suggest wasting time with that endeavor. Replacement body panels are the best option. Reading up on the por15, I would only use that on a frame and not on a panel, but that's just me personally. I'm not in the rust belt, so in a desperate attempt to prevent rust, I can understand why you guys do everything possible,to prevent metal cancer wherever it may pop up.

You only say that because you live in Arizona.

Where I live it goes from +40C t0 -45C. I see rain and snow and hail and freezing rain. I see humid and dry conditions. I see road salt and road gravel. I see blistering hot sun and everything else you can imagine. And my truck sees that 24/7 52 weeks a year.

 

[smoothandlow84]

Sounds like it blows to live in the great white North eh.

 

[MadOgre]

Sounds like it blows to live in the great white North eh.

Its definitely nothing like Arizona!

 

[bucket]

I don't cover over rust! LOL that would be insanity! Rust gets cut out not painted over. Even my frames get sand blasted before POR15ing them!

Even though POR15 claims you can. I wont!

Not to mention it would look like complete crap!

Well we agree on something there.

I find POR15 useful for exterior panels only if it's used to slow rust down until you have time to fix it properly. I still would never coat an entire panel with it though, as it kinda has the same characteristics of powder coating. I've seen quite a bit of powder coated items that the coating actually promoted rust. Despite what people say, it CAN chip or scratch, letting it start to rust. But the coating is strong enough that it doesn't flake as rust bubbles up under the coating. Since it tends to hold together, it helps dirt and moisture collect, speeding up the rusting process.

 

[MadOgre]

Well we agree on something there.

I find POR15 useful for exterior panels only if it's used to slow rust down until you have time to fix it properly. I still would never coat an entire panel with it though, as it kinda has the same characteristics of powder coating. I've seen quite a bit of powder coated items that the coating actually promoted rust. Despite what people say, it CAN chip or scratch, letting it start to rust. But the coating is strong enough that it doesn't flake as rust bubbles up under the coating. Since it tends to hold together, it helps dirt and moisture collect, speeding up the rusting process.

Ya your bang on with that! That's why its so important to get proper adhesion, and the only way to do that is to follow the instructions to a T using their pre application chemicals.

It will rust a spot right out before you notice that you have a problem, but not if its applied properly.

 

[MadOgre]

I guess with that thought in mind I can see why guys would want to stay clear of it. I have had great success with it over the years. The only time it didn't work out right is when I didn't follow their application process fully.