Rust Bubble Repair With POR15

[George7941]

I posted about a rust bubble on my Sierra a few weeks ago. This rust is on the outside of the panel, the inside of the panel is rust free.

Today I used an aggressive wire brush on an angle grinder to remove the rust, prior to applying the POR15 Metal-Prep. After I wire-brushed the rusty metal I ended up with black coloured metal. This was before applying any chemicals. I wire brush a lot of small metal items and they do not end up black. Any idea what the source of the black colour is?

 

[mattwithcats]

Phosphate conversion coating...

Phosphoric acid reacting with iron...
Creates iron phosphate...

www.en.wikipedia.org/wiki/Phosphate_conversion_coating

 

[Donald]

Have you cleaned the metal off with acetone?

 

[Donald]

Originally Posted By: mattwithcats
Phosphate conversion coating...

Phosphoric acid reacting with iron...
Creates iron phosphate...

www.en.m.wikipedia.org/wiki/Phosphate_conversion_coating


I am reading post to say before he used any chemical.

 

[Donald]

Keep in mind the rust conversion products work best with a slight amount of rust.

I would use a self etching primer and forget the POR Metal-Prep.

 

[mattwithcats]

I bet they sprayed the metal while still molten. Top of metal is iron phosphate.

Saves having to spray paint metal with anti corrosion paint before primer coat...

 

[Trav]

For little stuff like this i use a spot blaster. It doesn't need a big compressor for a small spot.

http://www.amazon.com/TCP-Blasting-Recov...pot+sandblaster

As long as its not through you can fill the pits with JB weld, just squeegee in on good and flat so it just fills them then sand, self etching primer, primer filler, block it out and paint.

 

[TomYoung]

Originally Posted By: mattwithcats
I bet they sprayed the metal while still molten. Top of metal is iron phosphate.

Saves having to spray paint metal with anti corrosion paint before primer coat...


WHAT???? the painted metal in automobiles is primarily stamped. Even cast metal cools long before being primed. Please watch "How It's Made," and "Ultimate Factories" and other educational shows more and stop the crazy talk.

 

[George7941]

The black coloured steel appeared when I wire-brushed the rust away, before applying any chemicals.

I used the Metal Cleaner that POR15 supplied, instead of Acetone.

Metal Prep is a self-etching primer according to the literature I got with this POR15 starter kit
http://por15canada.com/super-starter-kit.html

The self-etching quality is mentioned on the POR15 website
http://www.por15.com/POR-15-Metal-Prep_p_15.html

I applied the first coat of the POR15 paint this evening and will apply a second coat tomorrow.

This is my first use of POR15 and I am not sure if I made the right choice. Googling brought up some negative reviews of POR15, among the positive ones. I will find out for myself in a few years.

 

[jeepman3071]

Originally Posted By: George7941
The black coloured steel appeared when I wire-brushed the rust away, before applying any chemicals.

I used the Metal Cleaner that POR15 supplied, instead of Acetone.

Metal Prep is a self-etching primer according to the literature I got with this POR15 starter kit
http://por15canada.com/super-starter-kit.html

The self-etching quality is mentioned on the POR15 website
http://www.por15.com/POR-15-Metal-Prep_p_15.html

I applied the first coat of the POR15 paint this evening and will apply a second coat tomorrow.

This is my first use of POR15 and I am not sure if I made the right choice. Googling brought up some negative reviews of POR15, among the positive ones. I will find out for myself in a few years.


I used POR15 on the floors of my Jeep when they were starting to rust heavily. I followed the instructions and applied 4 coats plus the gloss black top coat (separate can). It seems to be holding up well so far. Prep is everything. I also read a mix of reviews when I was researching POR15. I found one review where the guy said he just blasted it away with a pressure washer and it was flaking. I think lack of prep was a major factor in that case.

 

[George7941]

Jeepman, I take it you coated the underside of the floor of your Jeep?