Letter 2654

Home anodizing. Myth or reality?

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I am looking into trying aluminum anodizing as a hobbyist. I have read some articles on the subject but before I dabble with different acids and solutions, I would like to find a good source for this procedure. Is there a way that I can set up a small operation in my garage or basement? I would be working with only one or two small pieces at a time. I did read one article were the author (Jim Bowes) tells to clean the part in a nitric acid solution (1-2 ounces per gallon.) Then put a combination of sulfuric acid and water (1 part water and 2 parts acid) in a bucket. Then make an aluminum "wand" and place that into the solution and attach the negative end of a battery charger to it. Then, place the positive lead to the part and immerse it. He then advised to wait until it no longer conducts electricity. After rinsing with cold water, dip into a dye solution. Is this something that can be done? Is it more dangerous than it sounds? Is there somewhere that I can get more info on "Anodizing at home?"

One last question, is there a way to do anodizing without using electricity?

Thanks, Tim.

Tim Mattsson

I myself have looked for home anodizing info, specifically for my paintball gun. Yes i could send it out, but where's the fun in that? Here are some things I have found on doing it at home:

• http://www.ptialaska.net/~airserv/anod.html [Ed. note: link was bad by 1/13/00]
• http://warpig.com/paintball/technical/paintguns/anodize.shtm [Ed. note: link was bad by 1/13/00]

There is a place on the web called XXXXX that sells home kits for the do-it-yourselfer hobbyist. Including a cool paint-on gold plating kit. Most paintball players love shiny things;)

Ian Carlin

Ed. note: 'XXXXX' was a company name which was removed at the request of the company.

Fun is important, but not the only issue. There is also safety, environmental ethics, and social responsibility. There is a divergence of opinion as to whether plating or anodizing at home is safe, environmentally ethical and socially responsible--and it has been debated on these pages for over three years now. So at this point I'll just add that people need to be fully aware that the chemicals involved are dangerous and can have an environmental impact.

Ted Mooney, P.E.
Finishing.com Inc. - Brick, NJ

My applause Ted. I have worked in the metal finishing field as an engineer for over 18 years. I deal with the safety, environmental and operating aspects of different metal finishing processes, including anodizing. The first and formost concern are the chemical hazards to the operators. Wearing the proper safety equipment is only half the story. The other half is having other people trained to help in an emergency. The solution of sulfuric acid mixed in water is no different than battery acid, one drop in your eye and you are blind. Just mixing the water in the acid can cause it to blow up in your face.

As Ted suggests leave these chemical processes to the professionals who can give you the results you expect in a safe way. This will allow you to continue with your hobby for many years to come.

Keep up the good work Tim!

Brian DeLucenay
- Van Wert, Ohio

I disagree. Unless you have absolutely no education whatsoever, and didn't read into the process before commencing it, anodizing isn't that hard. There are hazards, but once you protect yourself from spills, contain the sulphuric acid solution in a sealed box with an adequate fume hood, anodizing isn't hard at all, especially for hobby uses.

Dmitri Artamonov
- Mississauga, Ontario, Canada

Actually I shot battery acid in my left eye when I was 12. I poked it with a nail to find out what was inside. It shot into my eye and then fell into a puddle spewing its contents throughout. My dog then drank from the puddle. I didn't go blind, neither did my dog.

Tim Mulligan
- New Hudson, MI

Well, we posted your response, Tim. Keep your day job :-)

Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

I've done a couple batches at home from several of the home anodizing suppliers and it is safe. Read the instructions and there will not be problems. My father had a battery blow up in his face because he was smoking while working on his car - battery discharging while he was working on it and he suffered no long lasting problems and yes he got it in his eyes.

Russ W
tumbling - Livonia, MI

Ed.note: Sure, Russ; the dangers of batteries exploding and a face full of acid are greatly exaggerated because your father survived it. Let's get a campaign going to remove those warning stickers.

I have been anodizing parts in small quantity for quite a while now, and I have found that unless you ignore all of the safety tips, you can do it without mishap. And on the issue of hazardous materials, I found that for a small fee, my local landfill would take any of my waste and dispose of it properly.

Abe Hager
- Olympia, WA, U.S.A.

Again, there is room for multiple opinions on what is relatively safe and environmentally responsible, Abe. But as operator of this site I feel the continuing obligation to respond and remind people that they really do need to see the EPA's stand on this issue in the Code of Federal Regulations at 40CFR433 (which is available in most libraries and on line).

I see no way of interpreting it but that if you sell any product that you have anodized, or you sell an anodizing service, then the full weight of all federal compliance regulations and reporting regulations fall upon you. The waste is then categorically hazardous waste regardless of how innocuous you or the landfill operator may feel it is--in other words, because it came from an anodizing shop, it is 'categorically' hazardous waste no matter what characteristics you measure.

Yes, the chance of getting into trouble for operating a pint-size beaker in your garage is probably very small. But there is a temptation to grow, and the number of people jailed or losing their house and life to fines for operating their garage as a plating shop is not small. A plating shop in a garage attached to an owner's house in York, PA eventually landed the owner in the penitentiary; a chromium plating operation is a two-car garage in Odessa, TX is a Superfund site which has cost a million dollars and counting just in legal fees.

You are welcome to say to yourself that I'm silly and alarmist, but please read the law I referred you to anyway.

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

Well I hope someone can help me out. I have a paintball gun not sure exactly what they are made from would like some input on that part but I want to anodize it another color and want to know whats the best way to do that.
thanks,

Joe Tannahill
consumer - Southmills, NC

Being a regulatory compliance guy (I have my own business in product regulatory compliance) and someone who has done "home anodizing", I can also vouch for it being safe as long as you educate yourself prior to attempting it, and use some common (uncommon?) sense.

Read everything you can get your hands on and listen to those that have done it before you. That doesn't mean do everything that everyone tells you to do, you are on a *fact* finding mission before you dip your first part.

Don't go big right off the bat. Start small and increment yourself if you must do more.

Read the regs, and know that unless you start charging and/or your dumping waste haphazardeously, there is nothing special there. If you start doing this for others and/or get to a level other than just a hobby...be aware that you will have quite a burden placed on you. Nothing wrong with running a hobby line done responsibly. Just like nothing wrong with prospecting responsibly or making beer or wine for personal use in a responsible manner. You don't need to apply federal regulations that are not intended to be applied to the hobbiest...having said that, dump something into a stream or sewer and you deserve to go to prison for two reasons...one for breaking the law and especially for two...being so stupid.

Happy anodizing!

Incidentally, the aerospace company I work for wants to open an anodizing line because they think we pay to much for anodizing...I am preparing a study to show them that they would be crazy to bring this burden (administrative, cost and liability) on to the company for the scant amount we pay a third party who has being doing it consistantly and cost effectively since about the 40's. Since they have long since paid for their buildings and equipment, they have been exceptionally reasonable in our pricing and we have a long standing history...the owner sees a number and has absolutely no understanding that the number is peanuts compared to what it will cost him to bring this in house, he will though.

Garry Hojan
- Priest River, ID, USA

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