Anodizing question

I need to make a couple dozen .940" aluminum cylinders .940" long,
6061-T6 and coat them with a reasonably durable flat black (or very
dark) finish. They need to withstand a fair amount of handling and
joggling around (student lab use) without chipping so flat black paint
is just not tough enough. I will put a nice chamfer on the edges to cut
down on the chips.
How about anodizing? I can put a small hole for hanging through the axis
to hang them. Our model shop has a elaborate shop built anodizing setup
that is non functional. Since I need some parts anodized, I suppose I'm
tapped for trouble shooting it. I need some background on how/what
before I dive in. They guy that built it is not really available.
I'm striking out with google, I get a lot of discussion, very little on
a clean writeup of how to do it. I do get a lot of leads that point to
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is the "pay me $25 for my book"
Reply to
RoyJ
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Is the power supply working and all of the connections to the tank/s secure?
Reply to
buffalo
Pay the $25 for the book, it's good. I got the book and the chemicals and had my anodizing line running in no time. I never had any failures either, the very first piece of scrap I tested on came out perfect.
A did however manage to dissolve a lot of small holes in a pair of pants from the acid bubble-spray so wear expendable clothes. I did have elbow length gloves, chem splash goggles and a respirator on.
Pete C.
Reply to
Pete C.
If that's the only anodising you want to do, check for a local anodiser and ask. I recently made a centering microscope and a local one-man shop put all the parts through their tanks, along with someone else's bigger order for less than it would have cost me to buy the chemicals for a DIY job.
Reply to
Norman Billingham
You can anodize, powder coat or paint with Aluma-hyde (not sure of the spelling but it is a speculated aluminum coating). The more I do of it the better I like powder coating. I think powder coating (two or more coats, maybe even one coat) will definitely outlast anodizing.
I powder coated some steel wheels on a boat trailer over a year ago. They have been in and out of salt water probably close to 50-60 times and still look like they were just done. No stone chips, no cracks, and definitely no rust. I wish I could say the same about the painted steel boat trailer.
Heck you could powder coat the pieces and then bake them in the oven in the factuality lounge.
Reply to
Diamond Jim
Yeah, my doctor has gloves like that... /mark
Reply to
Mark F
========= Make it a class project and let the students help.
see
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Lidnsay also had "Finishes for Aluminum" by Reynolds Metals ISBN1-55918-194-X originally published in 1946 that has the information you need. If you can't find a copy I will scan the anodizing pages [4 different types] and send you a copy. When the anodize layer is first formed is porous and must be sealed. Simply put [black] dye in the sealer.
I like the following Dave Gingry quote and used it as a test question after we covered it in almost every class.
"What other people know, you can know; and what other people can do, you can do."
Let us know how things turn out.
Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.
John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).
Reply to
F. George McDuffee
=========== A quick google scan indicates even the reprint is now unavailable.
Send me a good email address. I scanned the 26 (1/2) pages and these are in a pdf file ready to go.
Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.
John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).
Reply to
F. George McDuffee
snip----
Unk, If you don't mind, I'd like a copy as well. My address as listed is good.
My sincere thanks for your service, sir!
Harold
Reply to
Harold and Susan Vordos
All you need besides household items are a DC power supply, some battery acid, and the nigrosin dye from Brownells. Or you can get complete kits from them. It does take some practice to get the process right.
Reply to
Richard J Kinch
And thanks to Unk, I got the manual and will have a go at getting the system to work!! Got to get going though, I need the parts machined, anodized, and tested by early January.
F. George McDuffee wrote:
Reply to
RoyJ
Is there any chance that you could post that on a web page for us to either download or peruse at our leisure?
mike
Reply to
mike
============
============= Having been there and done that [we used a Rhino robot with a photocell to detect white/black with a relay as a sorter] I suggest that you may want to consider using 1 inch diameter wood balls which are available for cheap from several vendors and easy to color. We dipped in an alcohol based wood stain.
Kids being kids, your aluminum pieces will walk faster than you can make them. The balls will walk also, but you can make up several hundred very quickly.
Feeder is also easy, just use an angle iron track with a slight incline and you can line up 20 or so balls for sorting. Retro reflector photocell was mounted to look thorugh a hole in the bottom of the track that also positioned the ball for the robot.
Good luck and let us know how the project goes.
Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.
John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).
Reply to
F. George McDuffee
=========== done --
see
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and scroll to bottom of page under "Miscellaneous drop box files" FYI my home page is
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Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.
John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).
Reply to
F. George McDuffee
I'd add some distilled water and an ammeter to the list, though these may indeed be "household items". Make up your solutions with distilled water, not tap water. Dilute the battery acid (available at NAPA) about 3:1 with distilled water. Set current to about 30 mA per square inch of work surface. If the current is either too high or too low the dye won't take as well.
I made a little current regulator for plating and anodizing.
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If you want a dark black nonreflective surface, beadblast the aluminum or etch it a little in some lye before anodizing. It won't be as pretty, but it'll definitely be blacker.
The metal must be absolutely waterbreak clean to anodize, but a lye etch will get it clean. Rinse in tap water and then in distilled water between the lye etch and anodizing. I just use a spray bottle filled with distilled water for the rinse. A gallon goes a long ways that way, always using clean water for rinsing.
Reply to
Don Foreman
I'd add that there are several "dyes" available commonly and locally that will make attractive colors in anodizing (though not dead black).
This might be surprising, but common Bic stick pens utilize a dye-rich ink that stains porous surfaces surprisingly well -- and surprisingly permanently. Many inks are pigment-based. The Bic inks contain some pigments, but also a lot of "true" aniline and similar dyes. I've stain-developed photoresists numerous times in a pinch, when our "Dyeveloper" was used up, and the only solvent available was clear carb-cleaner.
Watco spirit stains also are rich in dyes.
LLoyd
Reply to
Lloyd E. Sponenburgh
Thank You
Mike
Reply to
mike
Thanks for that. I'll make it up to Lindsay by buying something else from them for Christmas :-)
Mark Rand RTFM
Reply to
Mark Rand
Thanks. I did not know there were so many anodize proceedures. The only two I knew of was Chromic Acid and Sulphuric Acid. And as I understand it, the Sulphuric Acid one is the one used for hard anodizing. Do you have any information on when one would use the various proceedures?
Dan
Reply to
dcaster

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