Acid Wash 2 pac ?

[Dave_S]

Hi

Does anyone have experience with this ?

Is it damaging or does it work ?

Thanks
Dave

[UNCIVILIZED]

I'm assuming that you're referring to the 2 step preperation process for painting or bonding aluminum? If so, the answer to your question is yes, it does work.

The simple explanation is that aluminum flash rusts almost literally in seconds. So that in order to get a good bond to the parent aluminum, not the aluminum oxide coating (rust) which forms so quickly on it's surface after abrasive cleaning, is that you're using acid to wash this aluminum oxide off, & then the alodyne to seal out the air which would allow it to re-rust. So that you then have time to paint it, or epoxy bond it. And the alodyne may also enhance the grip of the coatings - paint, or epoxy, etc.

If you look at aluminum on the galvanic scale, it's about the same as zinc in terms of being lacking in nobility. So that without it's forming that protective oxide layer so quickly, an airplane would melt in a rainstorm. Okay, corrode into dust.

Another, "safer" way to paint non-critical aluminum parts is to wash them with white vinegar (acetic acid) while scrubbing with a scotchbrite pad. Rinse with fresh water. And then quickly coat them with a self etching primer. Which I've done to parts on some of my boats either due to lack of $ for the kit, or because I wasn't anywhere that it was okay to risk spilling acid... on the boat, on the ground, or into the water.

Worked okay, & it was only 1-part paint. So if I needed to redo things later, no giant fiscal loss. But the self etching primer seemed to hold up pretty well. Better than the paint actually. Enough so that the primer was solid enough to allow me to retouch the paint later on sans issue.

[44'cruisingcat]

I think Dave is asking about using acid to remove stains from 2 pack paint.

It does remove rust and brown water stains, but it also can remove the gloss, and can discolour the paint. If you use it, don't leave it on for long and wash it off with plenty of fresh water.

I've had pretty good success removing stains with the "eraser sponges". More work, but safer.

[Dave_S]

Thanks, I apologize, I should have been more specific. I was meaning for cleaning up. The paint is a bit oxidised and I was hoping to get a bit more the life out of the paint job.

[44'cruisingcat]

I've buffed mine with Farecla g3 compound and a foam pad . Polished with 3m marine wax. Came up very nicely.

[Dave_S]

Originally Posted by 44'cruisingcat

I've buffed mine with Farecla g3 compound and a foam pad . Polished with 3m marine wax. Came up very nicely.

It lists G3 as a fine finishing compound, how oxidized was it before. Mine is at the point where you can just see some gloss through the matt, I think it will come up but I might need to start with the next stage coarser grit.


and I'm going to do the unthinkable and change its name. The name has been hand painted on old school style.

[44'cruisingcat]

Mine mostly retained some gloss, but in some areas was very dull, almost chalky. There was some discoloration in some spots too, almost looked like mould. The eraser sponges were pretty good at removing this, as well as rust stains and brown water stains around the waterline.

The g3 brought the gloss back up nicely. Coarser might have been faster though.