Gregski

If leaving phosphoric acid on your part for 10 minutes works great, than leaving it for 20 minutes should work twice as well, right? Nope!

Funny thing this phosphoric acid is. You see it sorta has a reaction time, and after that it evaporates or something, so whether you leave a coat on for 1 hour or 2 hours it does the same thing.

So what works for me is applying it once, allowing it time do to it's thing, then using the steel wool to agitate it and help it out a bit, then applying a second coat, allowing that coat time to do it's thing, then agitating using the steel wool, then... well you get the idea, lather, rinse, repeat, it worked for me.

Now these fenders are not 100% done yet I will hit them again next weekend, and yes you can leave them like this and they won't rust, not in a week anyway, not in a month even, but I wouldn't put them back on the car like this un-coated with something, do you get what I'm saying?

Pic 1: Original rusty (40 years)

Pic 2: Wire brushed (2 hours)

Pic 3: First acid coat (10 minutes)

Gregski

OK, I figure I have one more hell day of head down get 'er done prep work and then I'm ready for primer. Here's a list of what I think I have left, see if I missed anything:

1. scuff up quarter panel ends (where the extensions used to be)

2. scuff up head light extensions

3. scuff up outside of kick panels where speakers went (bottom of A pillar)

4. scuff up stone deflector

5. scuff up insides of doors and coat with Rust Reformer

6. scuff up parking light doors

7. maybe scuff up rear bumper in order to paint it the color of the car (should I?)

I hate all the small ****. Clean garage [again] build outside temp paint booth for all the loose bits. Tape and mask off the car. Pray for good weather.

hightower2011

Greg, how much was the phosphoric acid? You've pretty much made my mind up for me on getting some to do my fenders.

It's lookin good!

Oh and my fenders are currently supported by a cardboard box, hahaha.

scootchu

That worked wonders. Looks great. Is Muriatic acid too strong or does it have to be Phosphoric acid?

Gregski

$15.00 bucks at Home Depot for 1 gallon of the stuff, I use it liberally don't want to miss any nooks and crannies, it will eat right through your garage floor, so go to your girlfriend's house to work on stuff if possible, or put some boards down first.

Gregski

YES, Yes, and yes! I hear it will destroy the metal and poison you at the same time.

Honestly I don't know I sucked in Chemistry all I know is Phosphoric is affordable ($15,00), accessible (Home Depot), and works. The auto parts stores sell you products that may work but in much smaller quantities so you will end up paying 10 times as much for enough material to get the job done.

slowstang70

I just finished stripping my hood and I used naval jelly and a wire brush but I didn't have a lot of rust and I don't think it was severe as yours. I just brushed it on with a brush so I imagine it would be awesome for nooks and crannies.

The phosphoric acid is an awesome idea and I am going to have to attempt it.

Really awesome progress none the less. I am impressed and motivated at the same time.

Gregski

I think you said it. For not a lot of rust and not as severe as mine you could use it. But to do large pieces I believe it is cost prohibitive, I don't think you can even buy it by the gallon, so 16oz at a time will break the bank. You are paying for the name, ie marketing. Also it proclaims to be jelly ie thicker so although it sounds ideal for the roof of the car and side panels as it won't run down as fast, it also won't seep in to the nooks and crannies as well as the much cheaper and thinner Phosphoric acid I used. Also all you need is a soaked paper towel and you lay that on the roof or the side of the car and whalla it won't run down either.

Thank you for the kind words, I'm just trying to help people out by trial and error myself to dispel all the myths out there.

jcoby

It MUST be phosphoric acid. Muriatic (hydrochloric) acid will eat both steel and rust, will seep into the pores and wait in hiding to destroy your paint from the primer out. It will also cause hydrogen embrittlement which could lead to cracking.

Gregski

Another 12 hour day in the stable. Just when I thought I had everything removed, I went to finish scuffing the front cowl area and ran into the windshield washer squirters. Well off with these pesky things. I doubt they will find their way back on the car, but I am still documenting these for those of you keeping score at home.