Anodizing Question: Titanium or Aluminum Racks

Titanium is inert in the process. Aluminum racks undergo anodizing themselves.

Further: when aluminum racks become anodized, they are no longer conductive on their surfaces so work hung on them is not connected to the power supply and doesn't get anodized.

Thank you for your responses. Aluminum racks cost more in long term. During the anodizing process, aluminum racks have to be stripped each time after use. Why would every anodizers use titanium racks?

Ken

Opportunities are never lost. The other fellow takes those you miss.

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Which leaves them virtually non-conductive, requiring contact points to be filed to make contact with the workpeice, if I read it correctly.

Torrey Hills wrote in news: snipped-for-privacy@j4g2000prf.googlegroups.com:

All of our anodizers use Ti & SS, Ti for any conductive parts, SS for most everything else, except the frames.

innews: snipped-for-privacy@j4g2000prf.googlegroups.com:

You use Stainless Steel (316?) racks for anodizing?

Torrey Hills wrote in news: snipped-for-privacy@l22g2000prc.googlegroups.com:

Both Ti and SS (what alloy, I am not sure), yes. Our anodizing operations are not "dip tank" type. We only anodize specific areas of the parts.

Can't imagine using aluminum for racks, it picks up surface oxidation just sitting there. Bad electrical contact then. You'd also have to strip the things after every use. We had titanium racks and used aluminum spreader bars for holding the parts securely. Every so often we had to dunk baskets of bars in the etch tank to clean them off, we used freshly dunked bars for every rack fill. Since the place had an aluminum extrusion plant, when the bars got to the point where they were too small, they squirted out some more for us. The racks were about 20' long and sat on two big pads for electrical contact at either end, so oxidation would have been a big problem. Currents up to 10000 amps. If you're going into production, use titanium. You'll need titanium hardware, too.

Stan

The OP is a shill, and a transparent one at that. Follow his links and you'll see that he represents a mfr of titanium anodizing racks.

Hi Ned, I e-mailed you from both Google group and my office this morning, so far I did not receive any response from you. Yes, we are a manufacturer of anodizing racks and have a separate website for that

It is not fair for us to say that my post was a shill without knowing why I asked that question. I would like to assure all other responders that what I asked was a legitimate question. Some of our customers are requesting Ti racks, some of them requesting Al racks. I do not know why. My background is Chemical Engineering and I want to know why. I did not try to promote our racks. In the response, I learned that some people are using SS for racks, very interesting. I posted the same questions in Yahoo Answer. One of the responders redirected me to The moderator liked the question and approved my posting. My posting ID is

46180.

Thank you... Ken

Opportunities are never lost. The other fellow takes those you miss.

| Torrey Hills Technologies, LLC | |

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Then I apologize. But I'd suggest that it's good form to disclose business affiliations up-front. Letting folks know where you're coming from may also improve the usefulness of the responses to your question.

Over last few days, I learned a lot more about why Ti is used for anodizing racks. Here is what someone shared in an e-mail to me:

"Ti is a lightweight metal with a high strength to weight ratio, good electrical conductivity and excellent corrosion resistance.Fo Racks fabricated from chemically pure titanium should be used. The titanium racks do not require stripping and are resistant to attack by most solutions used in the anodizing process. Titanium, being higher in price ($25/lb, August 2007) than the alternative, aluminum alloy ($2/ lb), is primarily utilized in high volume, long run production lines. Compared to aluminum alloy, titanium reduces rack maintenance costs and is far more economical in the long term."

I am getting more responses and will share them in this group.

Ken

Opportunities are never lost. The other fellow takes those you miss.

| Torrey Hills Technologies, LLC | |

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For those you are following up this thread, here is what Mr. Milt Stevenson, Jr. from Anoplate Corp, Syracuse, NY, USA commented in my

posting " A couple of more differences: aluminum racks bend more easily and work better for job shops that aren't doing repetitive, run-after-run of the same part. If you're having to squeeze titanium clips all day to rack parts, you're looking for a workmans comp wrist case for "reptitive motion syndrome." We can buy about 10 aluminum clips for the price of a single titanium clip. Also, there is a far greater variety of aluminum clips available. Furthermore, when it comes to hardcoat where current carrying capacity is critical, one square inch of cross sectional area of aluminum carries 650 amps where as titanium is only about half. Another factor is how well the unrackers are willing to squeeze the tips - if they don't and just pull the parts off the rack, the spring back will gouge the parts far more with titanium. Each one has its own merits. Lastly, last longer is a myth if you have any fluoride in any deox or desmut on the line; it will chew up your titanium racks and render them worthless in short order."

Thank you,

Ken

Opportunities are never lost. The other fellow takes those you miss.

| Torrey Hills Technologies, LLC | |

| | |

? 2007?8?19???? UTC

+8??11:28:28?Torrey Hills??? ?

Actually,titanium works better in the alkaline solution,while in the acid t he aluminum should be fine. Any more questions,please feel free back to snipped-for-privacy@qctitanium.com Armstrong