Anodizing aluminum

I am going to be anodizing some aluminum. Would anyone be interested in a mini class in aluminum anodizing and dying? I’m not an expert, but willing to share my experience and set up the chemicals and Hardware to get the job done. It is fairly straightforward.


I’m interested!

I am trying to decide whether to be the chemist and buy sulfuric acid from the supply house, be practical and buy drain cleaner made from sulfuric acid, or be a mad scientist and make my own from Epsom salts! My heart says be the mad scientist, but my brain says buy the drain cleaner. I am thinking if we have a group of people, we could make the chemicals in quantity and store them in Home Depot buckets. If everybody has some aluminum parts that are clean and ready to go we could anodized them together. I have purchased a few dyes That are meant for anodizing. I figure start with the good stuff, then we can experiment with things like Rit dye or Printer ink. Anyway it should be fun.

I’m interested as well! I’ve been making some chess pieces on the lathe out of brass and aluminum, but I’m not in love with the difference in weight, so I thought that I could perhaps make them all out of aluminum and anodize them. They probably wont be ready by class time, but the knowledge would be useful.

If this is to be done at the hackerspace for anything other than a one off class this has to have a hosting agreement setup before anything is brought in.
There are a lot of safety and disposal things that need to be addressed in the agreement for something like this.

There are also class requirements that need to be met if you would like to teach a class here, that I can send after Wednesday.


I was wondering about what the safety and disposal requirements were. The chemicals are reusable, but hazardous. I would be interested and teaching an ongoing class. I want to make it cheap So that it’s affordable and use the proceeds to fund the initial set up Materials and donate them back to hacker space. I would front the set up myself. The initial set up should run about $300. I would like to set up other self-sustaining projects to increase the variety Of courses offered a hackerspace.
The chemicals in question would be sulfuric acid and sodium hydroxide. I would need a heat source to boil water. The rest of the materials would not be hazardous. We would need to look at How to store and make available the chemicals. I could store them offsite myself, but then they would not be available for other members. If we’re not allowed to bring the chemicals in the building, it could even be done outside. That would really limit the utility of the process. I would be OK with a one off class, but during Covid this would limit participation. I could do an instructional class on zoom. I would imagine most people want hands-on Experience. I am going to do it for myself anyway. I know there is interest in anodizing. I just want to share the experience.

Sounds very Feasible. Since chess pieces don’t have anything to hold onto with a wire, they should sit on their base in the baths. The bottoms would not be anodized. The bottoms of chess pieces are often covered with felt. Once the aluminum oxide is formed on the surface, it no longer conducts electricity. So you couldn’t do one side, turn it over, and do the other side. Sounds like a cool project. As a teenager, I made a Chess out of vacuum tubes with epoxy bases. It was difficult to play chess with, because people forgot which pieces were which😁

Fred R. Martin, M.D.

Or better yet, you could drill a hole in the bottom of the chess piece and wedge a titanium wire in the hole. The piece could then be suspended upside down. This would make better contact electrically than sitting on the anode. If the piece moved while sitting on the anode, the bottom will get oxidized and lose its electrical conductivity. The bottom would be anodized except for the contact points inside the hole

By the way, both sulfuric acid and sodium hydroxide are commonly used as drain cleaner In higher concentrations than we will be using. That should simplify disposal as they are both approved for use in Household drains. I could actually buy the drain cleaner versions if that would simplify things.
As far as the papers for teaching your class, I also volunteered as well as CStaley To teach a cutting board class. He And I have spoken And Kye has recommended that we teach different but complementary courses. He wanted to teach a course in processing rough lumber. I would concentrate more on glue up and embellishment. We would both need the paperwork for that. I am open to any guidance that you have.

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I think any chemicals bought consumer-style retail should be fine. If you do leave a bucket/container unattended, its contents must be clearly labeled (eg masking tape and Sharpie). Anything bought commercially that doesn’t have its all-the-fine-print consumer label on the container should have its safety datasheet printed out and posted nearby (binder, clipboard, folder, or something with a label to the effect of “Safety Datasheets”) if it’s left unattended at the space.

Good point. I think we should have MSDS sheets on every chemical and hackerspace. We should make a binder and keep it near the first aid kit. We should also laminate sheets near the chemical itself. And we can put links to MSDS online on the computers. Nothing worse than having an accident and not being able to find what you need. by the way, do we have an eyewash station and an emergency shower?

I’m definitely interested. What about next steps? I’ve got some parts I’ve been wanting to do but haven’t fabricated yet. Might take a month or so after cutting them with a water jet.

So if anyone wants needs something cut could pool resources.

We could use practice pieces until you were ready with your waterjet cut pieces. Then we could do it again. Right now it’s an idea. I don’t have an approval from Hackerspace yet. Working on it.

I’m interested. I’ve got a LOT of aluminum tubes (6.5” x 1.5” OD, ~ 1/16” wall). I can donate some of these to the cause if anyone wants to use some.

Edited for clarity.

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That would probably be welcome since metals for you is closed down for their move.

Fred R. Martin, M.D.

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Well you are talking about two separate but complimentary things, which are a hosting agreement, and class requirements.
The board is finalizing some revised class requirements that should be done Thursday.

For the hosting agreement you need all info such as :
1.where is this going/space requirements,
2.Power requirements
3. Benefit to the community
4.Health and safety issues adressed/ MSDS/ clear chemical disposal plan as Jon mentioned
5.An operational/cleanup document that is detailed enough with pictures etc. that anyone who has taken the class even 6Plus months ago can be confident in using the equipment safely and proficiently. ( I am sending the manual mill follow up tomorrow which has the Tormach operation document that is a good example)
6.Then you need to setup the class that is taught regularly (requirements probably Thursday)
You also need a back up teacher
7. Clear plan for maintenance with multiple people accountable and document who is responsible maintaining/purchasing supplies etc.

That should get you started,


Thanks. Looks feasible. I will be back in Austin in the morning (I’m working tonight so I’ll be sleeping). Will get on it after that. Thanks for your guidance. I’m working on the first aid Kit. MSDS in important part of that. I will try to take on that project if that’s OK. I will try to locate documents at the point of storage/use. I will try to locate emergency contact numbers such as poison control, Chem track, 911 should cover emergency services, but we should have the numbers for police, fire, Ems, location of hospitals with addresses anyway. I will re-print and laminate the document on the first Aide kit which instruct you to give the address of hackerspace and not the name Which is not displayed and only confuses the issue (Although aTX hackerspace is now listed with information) If we don’t already have one I will make an MSDS notebook and as I said Will try to put a link to MSDS online on the various computers in the space.


Also interested. Thanks for organizing and figuring out materials!


Also @Fmartin we made some emergency call lists for the front door (printed on a laser) if that helps get you started. Thanks for working on this!

Thanks @kye. I’m going in for some maintenance work on the computers, the dust collector, and preparing for a class I’m going to teach I’m cutting boards. You mentioned scheduling this on Skeeda but I don’t see where to do it. I will just schedule the wood shop so that they can track me. I will need to cut some wood for the class. If you can show me the mechanism to put maintenance on Sketo I will do it