Stripping rust with acid?

[Darrman]

I have spent the last couple days stripping all the old bolts and small parts with muratic acid, works so good its not even funny.
However it doesnt really do anything to paint except make it gummy.
So now I am wondering what would it do to thinner metal, or metal with a smooth surface? My bumper valance filler peice is rusted real good on the bottom, and I think using a wire brush would tear it up, because of some pinholes that are already there.
So would it be safe to try the acid, or would it be too risky?
Thanks!

[averagef250]

You must have a lot of acid!

Might as well try it.

[layedout72]

you could always try the electrical/arm n hammer method..

[Darrman]

Yeah, I work for a water treatment chemical production plant, so I have a good source for acids.
I have seen that electrical dip, seems to work, but takes days depending on the size. This Muraitic acid takes minutes and strips it to bare metal, electric dipping leaves a black film on the parts.
I will ask my chemical guy tomorrow what he thinks.

[layedout72]

ive never seen any black film left from the tests i've seen done. thats not to say it doesnt, i just have never seen it. i also have read that it only takes like an hour or so to strip a control arm. I don't see why it would be so hard to have a bigger tank to dip the whole valance in.

[JWW]

Can you brush the acid on or do you have to dip it? I assume you just rinse the acid off after application.

[Darrman]

I havent tried the electric dip yet, but I did watch a show on doing it. They stripped a control arm, but said it took a couple days and the part was black when they pulled it out, which they said was normal.
This is pretty stout stuff, you would have to be real careful brushing it on, as it would want to spray droplets with the strokes. Probably better off dipping it.

[MadMaxetc]

Electrolysis is awsome. The black stuff is Iron Phosfate if I remember right. It is fine to leave on there if you are going to paint. If you are going to Chrome the part you will want to smooth and clean it up more anyway, so not a big deal.

[mljjones67]

So how do you do the Electrolysis

[Darrman]

Take Arm and Hammer Washing booster powder, a big container(big enough to hold the part at least), a battery charger, and a clean piece of scrap steel.
Mix the powder with water, deep enough to submerge the part, you will have to figure out the mixture yourself, then take the negative lead of the charger and set it on the part to be stripped, then submerge it, take the positive lead and set it on the peice of steel. Prop it in the corner where the steel is in the mixture, but not the chargers clip. Then plug the charger in and set on 2 amps. You will see bubbles forming after a few minutes, lets you know its working. Walk away and let it do its thing.
This is the way I saw it done on the show.

[MadMaxetc]

This is the site I use...

http://antique-engines.com/electrol.asp

[mljjones67]

thanks guys thats awesome!

[averagef250]

But sandblasting is SOOOOOOO much fun!!!!!! Why would you do it any other way?

[Darrman]

I did some more parts this weekend. I set the hood latch, top and bottom parts, in acid. Man its like a miracle happened, they cam out perfect, look like brand new. Even with sandblasting you couldnt get it this clean without taking the latch apart. I will get some pics of me doing a hood hinge, before and after.

[lightning_msd]

on the article i saw, it said to use stainless steel, not sure if there is a difference, but they didnt say nothing about being black.