Hi all
I was always told that the panel has to be clean, sandblasted and 100% free of rust, before applying epoxy. I agree 100% with that and I'm not questioning it. However, about a year ago, I painted some engine parts with SPI epoxy and had some leftover. So I decided to do an experiment. What I did was take a rusty piece of metal measuring 12"x 12". I rinsed it with water and used 80 grit sandpaper to remove 50% of the rust from it. So the panel was still very rusty but not flaky. Then I applied Ospho to it and once it dried, I neutralized and cleaned it with acetone. After that, I applied two medium coats of epoxy on it. Now, it has been 15 months since then, and the panel shows no signs of deterioration on the epoxy primer. As for the location of the panel, it has been sitting outside in a shaded area but has been exposed to some water from rain, etc.
I know that a lot of people are against treating rusty metal with acid instead of sandblasting it to make it shiny like a mirror before painting, but sometimes you have to take the easy route. With that said, is 15 months too soon to start showing problems with adhesion?
As far as the adhesion is concerned, it is still very solid and hard.
As someone new to painting and doing it as a hobby, I would like to know what is wrong with what I did?
I was always told that the panel has to be clean, sandblasted and 100% free of rust, before applying epoxy. I agree 100% with that and I'm not questioning it. However, about a year ago, I painted some engine parts with SPI epoxy and had some leftover. So I decided to do an experiment. What I did was take a rusty piece of metal measuring 12"x 12". I rinsed it with water and used 80 grit sandpaper to remove 50% of the rust from it. So the panel was still very rusty but not flaky. Then I applied Ospho to it and once it dried, I neutralized and cleaned it with acetone. After that, I applied two medium coats of epoxy on it. Now, it has been 15 months since then, and the panel shows no signs of deterioration on the epoxy primer. As for the location of the panel, it has been sitting outside in a shaded area but has been exposed to some water from rain, etc.
I know that a lot of people are against treating rusty metal with acid instead of sandblasting it to make it shiny like a mirror before painting, but sometimes you have to take the easy route. With that said, is 15 months too soon to start showing problems with adhesion?
As far as the adhesion is concerned, it is still very solid and hard.
As someone new to painting and doing it as a hobby, I would like to know what is wrong with what I did?