Acid dipping & E-Coating automobile and truck bodies for restoration

A. There are a lot of businesses in California that do the kind of work your looking for, you will probably be better off finding someone that will do a total "media blast" before the dip though. California is tougher on environmental issues than other states.

Sheldon Taylor
supply chain electronics
Wake Forest, North Carolina
2006

A. Hi Folks
Doing a ground-up frame off of my 62 impala SS later this year...hopefully. Been doing the Bodyman/Painter/Restogeek thing for 35+ years now & LOVE acid bathing vs. ANY kind of media blasting. Friend did the Aluminum Oxide deal on his '68 Jimmy & we're STILL blowing that crap out of the rockers a year later!
Trick is to wash/rinse everything VERY well, neutralize and dry meticulously (with heat). Epoxy prime the same day if possible. (I like DuPont Corlar -- but they've made it illegal here in CA! Grrr :(

A. Hi, Chuck. We've heard of the following shops that reportedly handle whole frames:
- Redi-Strip in Indianapolis IN, Roselle IL, Joliet IL, and Oak Creek WI;
- International Paint Stripping in Belleville MI;
- Kwik-Strip in Allentown PA;
- Metal Strip of New England in Worcester MA;
- Restoration Depot in Wauchula, FL;
- Pennsylvania Metal Cleaning in Monaca, PA.
You'll sometimes see such shops advertised in Hemmings Motor News; maybe try there as well if it's convenient.

If anyone can update this list with additions or deletions, please do. But we only print lists, not recommendations or slams. Unfortunately, more than once the IP address proved that a "testimonial" was from a shop posting with a fictitious name and posing as a "satisfied customer" :-) We apologize, but this site only works well if we limit it to technical help and camaraderie, and try to insure that there is no commercial gain from postings. Best of luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. For the most part, acid is not used, Cecilio. People may call it "acid dipping" as slang, but for rust removal they actually they use alkaline derusting formulations or iron phosphating solutions which are not corrosive.

For weight reduction, as opposed to rust removal and paint prep, there is apocryphal talk about acid dipping to thin down the gauge of the metal for advantage in racing -- but I am not familiar with it myself.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

Q. I'm building a racecar and am trying to remove weight from the car without being noticed. I recall fenders, doors, and hoods being "acid dipped" back in the 1960s to remove weight before fiberglass components were readily available. The rules in my class prohibit fiberglass pieces. Any ideas where I can have these pieces dipped and made thinner to reduce weight? What will be the surface texture after dipping? What percentage of weight can be removed from a fender? Any idea of cost?
Gentry Zentmeyer

A. First of all, I hope the part about "not being noticed" does mean that you are trying to "bend the rules." I'm only posting an answer to talk about the theory, not help you cheat.

"Acid dipping" probably means just that. Acids like hydrochloric, nitric, or sulfuric acid will attack the metal of a part, and gradually dissolve it. Many plated products are normally dipped in acid right before the plating tank to clean the part and dissolve any rust/oxidization that would come between the plating and the metal part.

You would need to dip a part for a long time in concentrated acid to reduce the weight of a part significantly. Also, any coating or plating would most likely be damaged or removed in the process. The surface of the metal would be bare and will soon begin to rust unless it was quickly painted, plated, or coated. The surface texture would probably be smoother after the dip. The resulting vat of acid would then need to be disposed of responsibly, not just poured down a drain or on the ground. How much weight can come off? I'm not sure, it depends on how skilled you are, and how fragile the part is. I doubt you could get more than 10% weight reduction.

Also, I would be concerned about the function of the part afterwards. It might malfunction or break if tampered with. That fender would not be guaranteed to protect you in a crash if it is tampered with. This acid dip option just seems way too much trouble than it is worth. My engineering opinion on acid dip to reduce weight is two-thumbs down.

Have you considered making the part out of plastic, aluminum, or magnesium? These materials are fairly strong and lightweight.

Tim Neveau
Rochester Hills, Michigan

A. Cars are definitely acid dipped for weight, in racing of course. Here is a link to the mods done to a Camaro Z28 to get it race-ready:

http://www.is-it-a-lemon.com/used-car-history/chevrolet-camaro-racer.htm

It is about the hassles they had getting the Z28 race worthy, and includes info about the acid dipping. There are plenty of other sources on the web that will explain how and why cars are acid dipped, but basically it is done when a car company wants a team to race their brand of car with the body unmodified (as far as anyone can see). In the past especially, most cars were fabricated with a pretty heavy gauge of steel, dipping in those cases could really bring the weight down. The use of acid in racing to give all kinds of advantages is nothing new, for example acid porting intake manifolds. This is sometimes done to circumvent rules in stock car racing where there might be strict rules about what modifications are allowed. Acid porting the intake manifold has very obvious advantages, but decent tracks will scope for mods like that, and if they are found the driver is disqualified and loses his entry fee. I know this happens for a fact, because I used to scope cars for a buddy of mine. His dad owned a popular dirt track in Greenville Texas and you'd be surprised at all the tricks those guys try to pull. Lots of those guys make a living on the stock circuit and an advantage like acid dipping or acid porting could make the difference between having a really good year or having to hang up your fire suit.
Sean Damkroger

2006

A. Hi, Mitch. Every new car is E-coated at the factory, so there is no technical challenge involved in the idea. But I don't personally know which jobshops offer the service to individuals. You might start with the previously posted list of shops offering dipping services. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey