Newbie home anodizing

[andrewjb]

Hi
i make chainmail (little rings) jewellery and im hoping to get some aluminium wire soon (to make colour full chainmail )

im completely new to anodizing and before i get the wire i thought i would practice some anodizing on some scrap aluminium i have in my garage

sorry if im blabbering or if you have answered hundreds of these questions before but there were so many threads i didnt know were to start looking

the tutorial i used was
http://www.focuser.com/atm/anodize/anodize99.html

i have a very small budget and cant afford much (maybe latter when i get some profits out of this)

first i got out my 12v car battery recharger
a plastic container
some copper wire
a lead fishing weight
a few old scrap pieces of aluminium (a washer, a screw, and a small piece of sheet metal)
food die

the acid i used was a mixture of water, vinegar, Muriatic acid

my first test was with the aluminium washer
i hung them in the acid mix with copper wire (making sure their was a good connection)
then i put the positive clip on the copper holding the aluminium and the negative on the copper holding the lead
i turned it on and left it for 15m or so until the bubbling slowed down
the lead seamed to bubble a lot more than the aluminium
i took it out and boiled it in a mixture of blue food die and water for 20m
then i rinsed it under water, it Was Blue
before i put the washer in i filed away the surface of one side
that side seamed to take the colour much better

i tried to to this again but it failed on both the sheet metal and the screw
and i don't know why? the connections seamed fine and they both bubbled

a few reasons why i think it didnt work the second and third time is
i didnt change the acid?
they were a bad alloy?
i used a different die (green)
left them anodizing for too long?
temperature?

any one got any suggestions on how i can get it to work again?
this is still my first day trying.
and i couldn't find any desmutting or sealers things

is there any steps im missing? or am i doing something wrong?

all comments, criticisms, questions are welcome

[sswee]

Go here and download the PDF file. Read it through and come back with your questions. Your way off base on too many things to get good results. IE: Battery electrolyte and distilled water at a 1:3 ratio, No metal in the tank except alum. or lead. It isn't hard but you need to back up and start with some good information. SS

[mcaswell]

The instructions you were using were our old methods, before we discovered LCD Anodizing, thanks to the late Paul Yursis, known on these pages as Fibergeek. (Boy, I MISS that guy!)

I did the tech support for the old and new systems, and I can tell you from first hand knowledge, that the old system absolutely SUCKS!

You need to FORGET EVERYTHING you read and start over completely.

Download the pdf file. http://www.caswellplating.com/kits/lcd_ano.pdf

Sorry to put this so bluntly, but you will be thankful when you start using the LCD system!


Mike Caswell

[andrewjb]

thanks for that link, ill probably wait a couple of weeks till the holidays when i have more time to get the supplies,

any suggestions on where i may be able to find anodizing sealant, desmut, proper dies locally?

also one of the main reasons i became interested in this was i heard talk of people using " glow in the dark" dies and dies that glow under black light
to make cool aluminium chainmaille. any one know of any places that sell special dies like them? i would be interesting in trying some when i get this whole thing working.

[sswee]

You can boil to seal without a nickle acetate sealer.
The desmut is best gotten from Caswell.
There are dyes that will work but don't give consistant results or desired color and will not hold up to UV light, from personal experience the professional dyes from Caswell are the only way to go. I am not familiar with the glow in the dark dye.
For good results read up on the 720 rule. Any questions on it I can help with. You'll need a lead or aluminum cathode with a surface area equal to or larger than the surface area of the part you want to anodize. If you can find a power supply that is CC capable, it will be the easiest and best way to anodize. If not you will need to control the current with something like automotive light bulbs or plug your charger into a light dimmer switch. A couple of cheap DMM to monitor the voltage and current are needed. You can find a roll of some small alum. wire at a craft store or hardware store to hang your parts. SS

[andrewjb]

thanks for that info SSWEE

i couldn't quite find the 720 rule , but i downloaded that calculator any way and im guessing i have to work out the surface area of the piece i want to anodize so i know what the optimum currency , time and peak voltage would be

hmm , working out the surface area of coils of wire (i would later cut them into rings) seams like a toughie seeing as im only in year 8 but my guess is i would work out the surface area of the amount of wire i used

Eg. say i use 1mm thick wire and make a coil using 2 meters (2000mm) of wire

Pi x 1 = 3.14
3.14 x 2000 = 6280

that means there is about 6280mm²

am i right?

in case im confusing anyone here is a picture of a coil (that coil isn't aluminium)

and does sealing in boiling water work just as well?
CC capable?, ill probably stick with the light dimmer switch idea.

and once again thanks guys for all your help with this. i really appreciate it

[sswee]

Paraphrased: A anodic coating can be grown to 1 mil in 720 amp minutes at 1 amp current density (CD).
720 * desired thickness in mils = run time / current density = final run time
720 * .5 mil = 360 / 4.5 CD = 80 minutes
Current density is amount of current used per square foot.
4.5A CD / 144" = .03125A per square inch
.03125 * square inch of part surface area (SA) = set current or the current needed for that part. If you run 5 of the same parts then you have to X5 that current.

You have the correct calculation for the SA. Cutting into rings first would probably be best although the hardest to get a good electrical connection. The coating will not take alot of flexing without crazing. It is very hard. You should be able to work with it by coating from .3 to .5 mil thick. the thicker you go the more prone to cracking it will be.

Boiling in distilled water does good. It is probably better since you said this is for jewelry and I've been told there are alot of people allergic to nickle.

CC capable is constant current. A constant current / constant voltage (CC/CV) power supply can be set at the desired current and it will vary the voltage to maintain the set current. If you go with the light dimmer method, you will need to monitor and adjust the voltage through the run to maintain the current. SS

[acidrain]

I'm not sure you will have satisfactory results anodizing your coils, unless you stightly stretch them out so they are not touching between coils. There is a good chance the coils will not anodize where touching.
Also, when you pinch your rings together to make the mail, the coating may scratch, or crack in that area.
The supplies you will need from Caswell are:
SP cleaner/de-greaser
De-smut
Dyes
Sealer

Get your acid from your local battery supplier... I got mine at Budget Batteries 5gal. for $12.

[andrewjb]

OK ill see about finding a CC power supply , sounds more reliable

and ill probably be using nylon jaw pliers for the rings for closing and opening the rings so i don't scratch the surface

i also know many chainmaille who live in the Sydney area so hopefully ill be able to sell some to them... at a reasonable price

[sswee]

The CC/CV PS is more reliable and you'll get more consistent results. A 3A/15V or 18V will do the 2 meter coil at a 4.5 CD. If you anodize a coil then cut, you could leave the end sticking out of the electrolyte to hook an alligator clip to for you electrical connection. You'll probably be in for some trial and error to find what will work best for you. Let us know how it goes. SS