Acid Dippers - ?

[Shakey]

I have never taken anything to get acid dipped before but I am considering having my suspension removed and cleaned by the folks in the link below.

http://www.metalcleaningservices.com/

I was turned onto these folks by another Mopar enthusiast who uses them for a lot of different jobs during his restorations.

I plan on taking my front suspension off and having these folks dip the parts prior to me painting and rebuilding the front end.

Any thoughts or feedback with regards to this type of process?  Any pros or cons?

I am not really concerned about the sheet metal on the car, mostly suspension pieces and hardware such as nuts and bolts.

[Ghoste]

If you're totally confident that they can completely neutralize the acid afterwards.  For me personally, I think it would always be in the back of my mind.

[Shakey]

If you're totally confident that they can completely neutralize the acid afterwards.  For me personally, I think it would always be in the back of my mind.

Neautralize the acid afterwards - as in completely clean it off of the surface prior to returning the parts to me?

Always in the back of your mind - as in what way?

What would be the drawback or backlash?

Here is a quote from their website:

We offer our in-house developed hot caustic soda based chemical stripping of automotive finishes including cathodic E-coat. This methodology offers intrinsically safe removal of coatings from precision heat treated or critical parts (such as suspension parts). Parts are easily coated.

Rust removal is achieved using our exclusive phosphoric acid based cleaning system.

WE DO NOT USE CORROSIVE HYDROCHLORIC (MURIATIC) ACID as it is known to etch metal, embrittle welds and cause rust problems in the future.

All parts are washed with high pressure water and then treated with a rust inhibitor.

Aluminum parts, rims or engine components are easily and safely paint stripped in our cold strip solutions.

Steel shot blasting is available for some parts.

Thanks for the input Ghoste!

[Ghoste]

I can't dispute what they are saying I can only offer personal opinion.  Acids tend to remain as acids unless they are neutralized.  I'm probably wrong but it is a long time since I took any chemistry class.  The one sentence in their blurb about muriatic spells it out as far as acids embrittling metals and continuing to eat away at elementes long after their application.  Isn't caustic soda different than an acid?
I don't know but I've heard too many stories of acid dipped race cars getting weaker as time marched on because there were pockets in the structure where the stuff was still working away.  Use some to strip off paint from sheet metal sometime and then try wiping it all off and come back later and see how quickly it accelerates the oxidation process.
I wouldn't do it but as I said, that's based on a personal opinion that I can't use to dispute their claims.  If they are putting it in print that they are using their process on suspension components, they must be doing something right.  The legalities would be too huge to ignore in that case. 

[bull]

There's more of a risk in the metal being damaged with acid dip compared to media blasting. For a K-member I would recommend you have it blasted (probably sand) and then powder coated or primed with a self-etching primer and then painted. But to each his own.

[daves68]

Not an expert on dipping but do know some chemistry, here's a quick chem lesson.. Muriatic acid, also known as hydrochloric acid, is an aggressive acid that will actually eat away at metals. That's why it was used to lighten panels on race cars. One of the effects, as mentioned in another post, is hydrogen embrittlement where the hydrogen ions in the acid attack the metal structure and weaken it. Muriatic acid is made up of Hydrogen and chlorine atoms- hence the name hydrochloric, or HCl.  Acids and caustics are rated on a scale called a pH scale. It goes from 1 to 14 with 1 being a strong acid and 14 being a strong caustic. Water is right in the middle with a 7 on the scale. When an acid ( low pH) is used, the corrosive action can be stopped by applying something from the other end of the scale  (high pH ). Acids can be "neutralized with a caustic, in this case Soduim Hydroxide. Sodium hydroxide will also remove paint but is a little easier on the steel. It will aggressively attack metals such as aluminum, pot metal, etc. Don't try cleaning your carb or aluminum intake in this stuff as it will make a cool fizzy thing for a while, then start to change form!
The phosphoric acis dip is actually a rust conversion process. This solution will stop the oxidizing process called rust and change it into a non
decaying form. This is often referred to as phosphating. Most concourse restoration folks know that Detroit used phosphated coating on nuts and bolts for that blackened look. There are products on the market that do this - one I am familiar with is Rust Mort. Brush it on and the rusr turns black and stops. It's the same stuff that's in Coca Cola. Ever heard of pouring Coke on a rusty bolt to loosen it? Phosphoric acid in the Coke does the work.
As for the whole dipping process, I too have heard good and bad about it. Seems the skill and experience of the operator is the key.  Thorough rinsing to remove ALL traces of the chemicals will ensure a long lasting paint job. I would choose carefully and talk to other customers before allowing anyone to dip my 40 yr old baby. Hope this helped you a little.
Dave

[dodgecharger-fan]

I remember the first time I looked into this process, I found a site that detailed everything. Their process included a dip in neutralizer after the acid dip.
The idea was that if the acid could get into the nook and crannies, so would the neutralizer.
Makes sense to me.

Even that neutralizer dip was followed up with a cleaning process and they also offered an e-coat service to completely seal everything inside and out.

I know, what's the site, right?   I umm can't find it...

My brain seems to connect this site with 69HEMI's restoration, but I don't see a link on his site.

[hemigeno]

http://www.redistripindy.com/

IIRC, these guys do all of Roger Gibson's work.

I wasn't sold on the process until I found out that they dunk the cars in a neutralizer too - not just relying on a hose to wash the acid out.  Seems like a neat process, although I've been told that you need to be prepared for some swiss cheese to come out of the tank, since it removes ANY rust/oxidation - even the stuff that doesn't look too bad.

When the Daytona goes in for resto, I plan on having it dipped, rather than media blasted.  There are just too many nooks and crannies that rust can hide which a nozzle can't get to.  If the acid can be neutralized as they say, it's the best choice IMHO.

[Ghoste]

Oh yeah!  I've dipped small parts in acid to prep them for stuff and Swiss cheese is a real good description of what can come back out of the tank.  If the base metal is thin guage, even surface rust will leave a hole in it's wake.

[is_it_EVER_done?]

I may be the least qualified person to offer an opinion on this as I live in the desert where a rusty battery tray is just cause to send a car to the crusher, but I see Three things I would want more information about.

1. they say (infer) that it is non etching to the metal, but the removal of rust is guaranteed to leave the metal rough. This doesn't bother me (rough but rust free metal) except that I hate when someone blatantly lies. ESPECIALLY up front in their inducement to use their services.

2. By their own admission, they only rinse the parts off with water after treatment (They can use all the superlatives that they want, but it still boils down to rinsing with water). I would be concerned that the rinsing would not remove all the acid.

3. The part comes back coated in a rust inhibitor which sounds good, but I would be somewhat concerned as to what the part looked like prior to coating (was all the rust removed), and does the rust "inhibitor actually stop rust, or inhibit it? and what exactly is the inhibitor?

I'm not saying it might not be a good idea to have done, but these were the first questions I would want answered if I was considering it, plus it sounds like it can get expensive.

Personally I sand blast all my own parts, use "Rust Bullet" brand rust proofing, and paint as desired. That way I know exactly that each step is done to my specs., and that the parts will last for a century. It's more work, but I can't remember the last time I paid to have something done that I didn't have to end up re-doing anyway.

[Shakey]

After all I have read here, I will most likely go with my own method which I have used on a few parts during this restoration.  I am going this route for a couple of reasons.

The concerns I have read in this thread leave me uncertain of the final results.

And time, yes it may be easier for me to drop the suspension parts off in Brantford, ON - about 45 minutes from the farm, and have them go through their process but in all likelyhood, it will be faster for me to take care of it in the garage this weekend.  By take of it, I mean using a paint / furniture stripper that works wonders when it comes to removing paint and rust from the suspension pieces.  This stuff is potent and works great.

Below are a couple of before and after pics showinig the results of using the furniture stripper.  The fella that owned the car before me had painted everything black.  My Father-In-Law and I felt that it would be best to clean all the items back to bare metal and coat them appropriately.

The rear gear housing turned out good and now it's on to the front suspension.  You can see in the last pic of my spindle, how clean it gets it as the one section I did (thought there was a part number under the grease, paint and rust) is clearly visible in the photo.

Thanks for all the input.