mumzer

as many of you know, I have designs for a billet control arm for late model 951s, and have sold a few sets over the course of the last six months, some to other rennlisters.

The arms begin as 44 lb billets of 2024 aluminum, and after machining can be left bare, or coated in a variety of ways to prevent aluminum oxides from forming and dulling the finish.

Earlier this year, the dates escape me, but 2-3 months ago probably, I sold a set to a Rennlister in the midwest for use on his DE car. We discussed his application on a number of different occasions, street use, availability of spares, heim joint seals, the works. We also discussed anodizing the arms as a surface protectant.

He was apprehensive about sourcing parts from a non-commercial vendor, becuase he was concerned about getting replacement parts should i lose interest in producing them. We made a deal on price, and i included a set of spare small parts to put him at ease.

1200 dollars and one set of billet arms changed hands.


Approximately 10 days ago, he sent me a message with numerous pictures attached that showed the arms after an attempt to anodize them. One of the arms was damaged with corrosion pits so badly, that it cannot be used. The other arm is apparently serviceable, but took very little color from the anodizing bath.

The anodizing was done by a shop that my customer has an exisitng relationship with, and that he trusts. The desription of the process he sent me of the acid/etch, anodize process, sounded standard enough, but apparently, one of the steps (and its not clear which one from the email string) caused a rapid bloom of cloudy debris from the arm, and upon removal a badly pitted part.

I do not know if my customer was present to watch the process or not, and havent asked that question, now that i think about it.

The second part, was not badly pitted, but took very little color (which is common with 2024 due to its alloying metal content and conductivity).

I believe both arms were plated the same day. It doesnt sound as though they were done at the same moment. I do know they were both made from the same piece of material.

it is POSSIBLE that one of the arms was already clear anodized. Im told by platers that i have talked to that the etch would have removed this coating...the damged arm was bare aluminum that had been cleaned off with soapy water after machining.


Upon receiving the email photos, i called him immediately to discuss, and sent emails to my material supplier and plater to seek advice. He told me that the plater did NOT ask him what alloy the arms were made from.

My material supplier responded and confirmed that he still had the certification and tracking parperwork for the billets. While i was speaking to the customer he replied.

I told the customer that i would stand behind my parts and take care of the situation...that he wouldnt be left armless and cashless if the arm were flawed somehow.

That's basically how we left it, that i would take responsibility for any error i made.

After we got off the phone, my plater called me back...he indicated to me that it was possible to badly damage any aluminum by exposing it to the wrong etch/desmutt, or exposing it for the wrong amount of time, or exposing it while racked on a material with which it was incompatible, or in a tank with which it was incompatible.

He described chemical reactions that could look like dropping alka seltzer into a bowl of vinegar...ie violent oxidation...which sounds a lot like what has happened to the damaged control arm. He told me to get the specific chemical compositions of the cleaning/etching agents, and he would re-create the process.

2024 is a FAIRLY unusual alloy for a car part...it has higher copper content (which tends to look black in the etch) and is markedly more expensive. It is much more common in the aircraft industry as a result of its physical properties.


The customer and i have exchanged a few more emails...his position is essentially that i should buy back the arms from him. His plater told him at the time he had never seen a chemical attack like this one. He trusts his annodizer, and his annodizer has done some tests in house, and is confident that he didnt cause the damage. The parts are unsafe to use, and he wants his money back.

I dont want to speak for the guy, and he may well opin here himself, but it sounds as though he has been screwed before by vendors (havent we all) and thinks that i sold him something other than what i told him. I welcome his comments here too.

I offered to replace the damaged part with a known good part (off my race car) via overnight courier and to pay to have a third party test the part to determine that it is the 2024 alloy i sold him, and that in fact i delivered exactly what i said i did.

He declined the offer, and has since replaced the parts with something else. While i have no problem with this, and i understand it given his experience with the arms he got from me, he wants me to refund his money for the damaged parts, without any explanation of what really happened to them. The customer wants to wash his hands of the whole thing and recover the money for the set of arms he replaced mine with.

At this point no one has explanained what happened. His anodizer says its not his fault. My material supplier assuers me he can prove the provenance of the 2024. I havent heard anyone say that its impossible for the etch/desmutt process to damage aluminum.


I feel a little like an engine builder who puts together a race motor, only to have the customer take it to a third party for modification, after which it fails. If I caused the problem i want to know why, so i can fix it...preferably by replacing the broken part.

What i dont want to do is pick up the tab for someone elses mistake. In this analogy, for all i know the motor could have been run on 87 octane.

I have no way to know if the third party was the source of the failure or I was without having a failure analysis done.

I have no way to know if during the intervening weeks since i shipped the arms, they sat in a shop full of abrasive dust, were cleaned with something caustic that could react with the contents of the anoziding tanks, or if the guys dog pissed on it, and the ammonia reacted negatively with something in the etch....I simply cant know.

In this instance its further complicated by the fact that the third party was helping out my customer as a favor and that they have an existing relationship.

To make a long story short...im struggling here becuase i want to do the right thing. I dont want to screw the guy, nor do i want to get screwed because someone else has made a mistake that they dont want to own up to.

anybody got any suggestions here....metallurgical, ethical, etc?

thanks


signed,


really confused

Sam Lin

The etch could very definitely destroy the aluminum as you describe. The fact that the ano shop did not ask the specific alloy is a telltale. Especially "as a favor" it's possible his job was not treated the same as a paid ano job, maybe just tossed in with another batch. Both the solution and the time make a huge difference in ano - what worked for another part may not work on yours, and if the batch was then run according to the other part's guidelines, or the guy got a phone call while it was running and it ran over a little, or one part was in the bottom of the bin and the other was on the top, there's a lot of ways for the arm to get messed up.

My opinion? He took your part and had someone else modify it - if the ano shop wasn't "doing him a favor," he'd be arguing with the ano shop for the replacement fees, not you. You've certainly been more than reasonable in making efforts to make it right, prove your honesty, etc - it's in no way your issue. No error on your end, and no lack of disclosure. The ano shop destroyed the arm.

Sam

Travis - sflraver

http://www.finishing.com/2000-2199/2101.html

My anodizing setup consists of a battery charger and a rubbermade tub from Wal-Mart. It's not worth doing any type of production because you can get small pieces done in qty. for around $.20 each right down the road from my shop. Its fun to play with one off stuff though.

Anyway, back to your problem. Above is one of the links to some info I scrounged up on the net when I was learning how to anodize and building my setup. I believe the first line answers all your questions.

Red1

I'm not a metallurgist, but since I work for the largest non-ferrous distributor in the US, I'll chime in.

2024 is indeed uncommon outside of the aircraft industry. My thought is the anodizer in this case was unfamiliar with the alloy (if he was even informed what it was), and assumed it would react to anodizing like 6063. He found out the hard way that's not the case.

IMHO, there's no way you should be on the hook for this one. He damaged the arms in a process unrelated to anything you designed the arms for, and that's tough luck. **** happens.

special tool

When he recieved the arms, was he informed on paper that the alloy was exceptional?

mumzer

there was no paperwork describing the alloy. We did discuss it though at some length, probably in email, as the purchaser was quite concerned about the strength of the arm.

this isnt a case of "you didnt tell me the arm was 2024"

from our last communication it sounds more like "they do 2024 all the time with this process and they say it should have been fine."

but i obviously wasn't there, and just dont know.

KuHL 951

I'm not at work this week so no access to my references. I think your problem is the copper content in the 2024 reacting with a "standard" anodizing process. Here's some links I found concerning the 2024 alloy: It's kind of egghead stuff but maybe it will help.

http://search.nace.org/query.html?co...rf=0&rq=0&si=1

mumzer

any chance you can quote the relevant egghead? its password protected. I really appreciate it.

What i dont understand is how an experienced ano shop would have missed it.

jerome951

Why do you say that one arm could have been already clear anodized? Is this something that you relayed to the buyer?

From where I see it, if you can prove both are made of the same material and had the same finish when you sold them, you should be off the hook. The fact that one arm was damaged and one was fine is a damning signal that the anodizer screwed up, assuming the arms had the same coating to begin with.

Red1

I talked to one of my anodizers. He said "it'd look like crap". He said it can be done, but it requires special handling. He said he ran a batch of 2024 pipe last week.

Perry 951

Get in touch with Alan C.

mumzer

simply because i know i had a set of clear anodized parts around, and the damage to the parts has me grasping for answers. It is possible that i sent him an anodized part.

I dont know, but in the interest of complete disclosure, i'm allowing that it could have happened.
Having said that, and im certainly willing to take instruction on this point, the etch desmutt would have removed the clear anyway, and were it in fact already coated, would only indicate that it was possible to do so without wrecking the part.

Like i said before, im not interested in screwing anybody (deliberately or by accident) but i want to make damn sure what happened before i start writing checks.


Thanks.

Travis - sflraver

A titanium rack was used for the anodizing. The fact that the material is 2024 is given away at the first step (etching). You can tell by the black coating on the outside of the piece after it is etched. The black coating is the coper that was not etched away.
Now what to do. It all depends. You could just be a good guy and eat this set. The rest of the sets you produce can come with explicit instructions for the arms NOT to be anodized. The other thing you can do is blame it all on the anodizer for not checking the material before he went ahead with the process and refuse a refund. As the manufacturer it is at your discretion.
I have issued refunds on products even though it was clear that a failure was not my fault to both me and the customer. Sometimes its just better to "write one off" and look ahead to whats next and not take the time to fight with it. Sometimes you have to stand your ground when you know you are right. It's up to you.

Matt H

Mumzer, I think from a business perspective you are doing a very good job. Trying to understand the failure is very important so it doesnt happen again. Obviously you are trying to make it right and that is very important. If the user is Alan C (I suppose that is what Perry means) then I think you two will come to a very good resolution as you both seem to be reasonable people.
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Travis - sflraver

The initial etching removes previous anodizing.