[4]

And now - My latest anodizing

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

PurpLev

Active User
Registered
Joined
Feb 22, 2012
Messages
888
Let me start by giving BIG thanks to Ed (eac67gt) for posting his anodizing post and process here:
http://www.hobby-machinist.com/showthread.php/12374-My-latest-anodizing

I have read quite a bit about anodizing in the past, but every online source I found back then was trying to pitch some product or another for sale and that always put me off (even though for mass production those offers seamed fairly decent and some still do). Eds' post (link above) showed that it can be done with more affordable and available products that were within closer reach to me - close enough that it was worth the try.

In an attempt to minimize costs, and use of harmful chemicals I tried using different solutions and components, and at first failed to get any decent results. the bigger culprit is that since I have yet to successfully produce good results I could not diagnose which of the components was causing the failure - was it the solution? the power supply? the connections? other?

I ended up recreating Eds process to the dot, using the same chemicals (almost) and power supply and finally got decent results. my next step would be to start introducing one change at a time and see if I can get same results using different solutions/components and I will post results as these attempts are made.

As not to repeat too much of Eds post feel free to follow the link above to his post and the process. the following is what i have been using successfully with a cost listing so that you can get the idea of total cost to get this started:

PartProductSourceCost
Power Supply10A/2A/55A 12V/6V Battery chargerHF$50
(can be had for $30 on sale)
Anodizing Solutionph reducer (Sodium Bisulfate)Amazon$20
Anodize Solution/Dye/Sealing/Cleaning waterDistilled waterlocal supermarket$5 for 6gallon
DyeRit Fabric dye (the larger container)local crafts store$4
Connecting wires12gauge aluminum wirelocal crafts store$4
Containers (anodizing bath, dye/seal pots)plastic container and cheap pots$20
Cleaning suppliesbrushes (pipe brushes etc)HF$5
Dye/sealer heaterDouble Hot platesAmazon$25
TOTAL$133


The above is a rough estimation and rounding up the numbers and is only to give a rough idea of cost. Obviously anything on that list that one already has will start lowering that TOTAL real quick.

My process was as follow (to recap Eds post):

1. Clean part excessively (I let it sit in white vinegar for 15 minutes, then washed/brushed it with dish soap and tap water several times, then sprayed with distilled water to rinse off the tap water which gave a clean part (following picture is prior to cleaning, but just to give the idea of the 'before' color state of the part):
IMG_20130322_213936.jpg

2. connected part with aluminum wire (I used aluminum wire from the crafts store that is used for making jewelry) and hung that on a metal conductor that is hooked up to the POSITIVE clip on the power supply. the NEGATIVE clip on the power supply is hooked up to a 6061 bar that I had both are submerged into the solution (made up of ~5lbs of the ph reducer in ~ 1.5 gallon of distilled water - I simply kept on adding ph reducer to the dist. water until it was over saturated and no more would dissolve in the water - ALWAYS ADD ACID (AAA) to water , never water to Acid). I then turned on the power supply and within a few seconds bubbles started forming over the Cathode (NEGATIVE):
IMG_20130326_203250.jpg
IMG_20130326_203317.jpg

I let it sit for ~2.5 hours all the while it was bubbling like that.

I tried to use a PC power supply in an earlier attempt that failed. I'm not sure if the power supply was the culprit as I've had other differences in the setup that might have been the root cause, but I did notice that the PC power supply was giving 12v DC whereas the battery charger that I used this time around was giving out 15v DC. just something to note for later when I do attempt the same process with the PC power supply (as a cost reduction).

3. After 2.5 hours the part will lose it's silvery aluminum tint and will have a slightly warmer matte tint to it. At that point I warmed up the dye in some distilled water to 120f-140f trying to stay under 140 so that the part will not start to seal (maintained heat at 130f for most). and hung the part with the aluminum wire in the dye, and let it sit like that for 30-45 minutes (I tried shorter lengths of time but the color wasn't deep enough).

4. After 2.5 hours, I boiled some distilled water to 180f-200f, and hung the part in there to seal it.

Now here I had a bit of a mishap. in an earlier attempt that failed (color was too faded):
IMG_20130326_013046.jpg

I believe that the dye I used was too watered down, so I stopped at michaels and got another pack of dye (this time the larger pack) and thought that I was adding it to my dye pot (left):
IMG_20130326_203335.jpg

but infact what happened was that I added it to the 'sealer' water pot, and ended up sealing the part in dyed water... yikes. I soon noticed that midway the sealing process, and replaced the dyed water with fresh distilled water for the sealing process, so am not sure if the deep color I did get was due to sealing it in dye, and if I didn't mistakingly take that step if I would get the same results - I'll know next time around :) but nevertheless, the part came out perfect! I left it hanging to air dry after sealing it for 30 minutes. and this is what I got:
IMG_20130327_075741.jpg
IMG_20130327_075939.jpg

you can see the difference between how the anodize/dye took in where the part was fresh off the lathe (2 rings on the back) as opposed to where I filed and sanded the part (front) which gave it a brushed look which I really like and what I was hoping to get.

All in all, good progress, good experience, and definitely opens up a whole lot of new possibilities. I really like how it's much more resistant to scuffs and scratches which is something that was always bothering me with aluminum parts I was making.

So thanks again Ed, and I certainly approve the process and suggest you try it out if you plan on anodizing anything.

here is my little anodizing area:
IMG_20130326_203414.jpg

As I will attempt making changes to the solution content/power supply, etc I will post my findings, but at least I know for certain that the above steps work and work well.

IMG_20130322_213936.jpg IMG_20130326_203250.jpg IMG_20130326_203317.jpg IMG_20130326_013046.jpg IMG_20130326_203335.jpg IMG_20130327_075741.jpg IMG_20130327_075939.jpg IMG_20130326_203414.jpg
 

thomas s

Active User
H-M Supporter - Gold Member ($25)
Joined
Jan 26, 2012
Messages
975
Good job that looks great. Wish I had a tank big enough to fit my 12' foot aluminum boat in
 

mtnlvr

Active User
Registered
Joined
May 13, 2012
Messages
83
Very cool results Sharon. Looks like a conpensator for a bullpup rifle. Do you have a picture of the whole rifle &
what type is it? Thanks for sharing.
 

Ray C

Platinum
Staff member
Registered
Joined
Nov 16, 2012
Messages
5,215
Sharon...

PC power supplies do all kinds of weird things -especially the Energy Star types. Some will shut off if they don't sense current etc...

Nice job on the anodizing. Hint: Suggest you draw your drapes or get on good terms with your local DEA team -kinda looks like you got a meth lab going...

Ray
 

PurpLev

Active User
Registered
Joined
Feb 22, 2012
Messages
888
Good job that looks great. Wish I had a tank big enough to fit my 12' foot aluminum boat in
Just do it at the harbor ;)

Thanks for posting your results Sharon, I really
want to give this a try.
you're welcome, you should give it a try. following Eds post really made things even simpler than they already were. and materials were mostly easily accessible

Very cool results Sharon. Looks like a conpensator for a bullpup rifle. Do you have a picture of the whole rifle &
what type is it? Thanks for sharing.
good eye. It's a IWI Tavor - airsoft replica. here is a pic with the muzzle brake prior to anodizing. the dye process really changed the overall look of the rifle:
View attachment 50882

Sharon...

PC power supplies do all kinds of weird things -especially the Energy Star types. Some will shut off if they don't sense current etc...

Nice job on the anodizing. Hint: Suggest you draw your drapes or get on good terms with your local DEA team -kinda looks like you got a meth lab going...

Ray
Thanks. the PSU actually gives me pretty consistent performance with ongoing DC power and has an internal re-settable fuse. the HF battery charger as you mentioned stops producing current when it senses a broken circuit. so if I pull out the part to assess the progress I have to reset the battery charger to get current back in there.

As for the lab look.... hmmm.... good point :thinking::whistle: lol.
 

eac67gt

Moderator
H-M Supporter - Gold Member ($25)
Joined
Nov 18, 2012
Messages
557
A Basic battery charger that does not have a "control" monitoring the charging process of the battery is what you need and are now using.
A PC power supply circuit is a "switching power supply" and if the +5v out is not loaded to at least 1 amp it will not regulate the other outputs correctly.
The supplies are designed around the +5v which is the main output on these supplies. I use one for my Cree Leds in the shop but I use the 3.3v out.
I have to hang a 5 ohm resistor on the 5v to get the 3.3 to regulate correctly. If anyone tries this the resistor has to be a minimum of 5 watt but I would go bigger.
The 5 watt which be it ceramic or wirewound will heat up pretty good. I am using a 5 watt ceramic but made a heatsink to mount it in.
With that resistor on all outputs "should" be stable including the 12v.

Good job Purplev.

Ed
 

PurpLev

Active User
Registered
Joined
Feb 22, 2012
Messages
888
Thanks again Ed for the inspiration and kick in the behind to get me started with this - much appreciated.

As for the power supply, that is an interesting input regarding the 5v circuit. I have been using this power supply for various other purposes from powering up my RC battery charger to electrolysis for rust removal (very much like anodizing only in reverse order where the part is hooked as the cathode) all with great success.

what irregularities have you noticed when the 5v circuit was not active that putting the resistor on it cleared up?
 

eac67gt

Moderator
H-M Supporter - Gold Member ($25)
Joined
Nov 18, 2012
Messages
557
When it stood out to me was when I put several Cree Leds on the 3.3v output and the Leds would pulse in brightness. It was not extreme but you could see it.
I put the meter on the supply and you could see all the outputs were bouncing around a small amount. Put the scope on it and it was evident there also plus outputs were not very clean.
Once I hung the resistor on the outputs cleaned up. From what I remember the switching power supplies we built at Honeywell were like that. The supplies were based on one primary output and the other outputs were dependent on that primary one.
Not all switching power supplies are built the same.
In your situation it seems that maybe if the loading was heavier for the anodizing than other things you have tried the output could become more unstable as far as regulation. If I am right you said you didn't try a meter on it to see what was going on.
It would be interesting to see what the voltage was really doing when you tried it.

I have messed with a variable power supply in the anodizing solution we are using and we I got down below 10v the anodizing didn't take correctly even though it looked like there was plenty of action. I also tried the voltage much higher. When I got up to 24v the current flow was so much the part started to heat up. This of course makes sense because the higher the voltage the higher the current will flow in this type of solution. I was not following any formula for the anodizing though. Once again I am no good with calculations anymore so the anodizing I do is by the seat of my pants like most things I do now a days.
From what I do understand though the higher voltage will help build crystal layer quicker but it is hard to control and heat from the process will cause crystals to seal themselves. This I have had happen also where I overloaded the tank and it heated up. I was set at 12v but had to much in the tank and being the voltage is regulated the current will increase with the load. Higher the current the higher the heat build up. My parts would not dye but when I took the part down to the deburring wheel the layer that built was extremely hard to remove just like a good anodized layer should be.
I hope this makes sense as I am good at bambling.
 
[5] [7]
Top