Rinse with ammonia after phosphoric acid?

[Zeke]

Did I read that somewhere? Or, what is the best way to neutralize the metal before prime?

[rdelmendo]

Milt-

You didn't use straight phosphoric acid did you?

I suspect (hope) you diluted or used something like Picklex or Metal Ready. I was always told to not neutralize with a base but to just wash thoroughly with water.

[kycarguy 935]

I found this on a Jeep site.

http://42gpw.com/acid.html

[Zeke]

Originally Posted by rdelmendo

Milt-

You didn't use straight phosphoric acid did you?

I suspect (hope) you diluted or used something like Picklex or Metal Ready. I was always told to not neutralize with a base but to just wash thoroughly with water.

Actually "The Must For Rust" is my preferred product. I've since read that a small amount of baking soda in water works as a rinse.

[Tim K]

Milt,

Do you care to describe what you're doing? I've been experimenting with different products, and I'm interested in your results.

Tim K

[cgarr]

I used to use baking soda in water back when I worked with body lead, it really cleaned up the metal nice and never had any kind of surface rust that you normally find a day later.

[Jagshund]

Ewwwww! Acid?! Let me wring my hands a bit . . . I use DuPont 5717S (yeah, I had to go look in the garage to get that number so I'm not a total geek) just as the directions state. It took a bit of bravery to put water on fresh metal, but it'll be another 40 years before we find out if that was such a bad idea . . .

[chris_seven]

I would use a mixture of 15% Phosphoric Acid and 5% Citric Acid (Citric Acid has a high affinity for iron). If you dilute this to a pH of about 3-3.5 it will be quite effective.

The problem is that this mix will tend to run off any vertical panels and leave black streaks.

It is fairly easy to turn into a gel with cheap wallpaper paste.

It will then stay on the shell for a reasonable time before it dries out.

We have used this mixture for some time and it is quite effective. It doesn't need neutralsing but it does need to be washed off and then if the shell isn't dried quite quickly it will flash rust.

We use a diesel powered steam cleaner to wash off the mixture and the shell then dries out very quickly with no flash rusting and a shiny finish.

We then apply a de-watering oil.

[Bobboloo]

My preferred method is:

1. phosphoric acid
2. rinse with water
3. Eastwoods Metal Prep (acid, water, zinc and phosphate)
4. wipe with mineral spirits.

No flash rust and the zinc, phosphate gives you a cold galvanized surface.