Anodizing

[deere_x475guy]

I just spent the day getting set up to try my hand at anodizing. It's pretty much a run of the mill home shop setup. 2amp/10amp battery charger, battery acid mixed 50/50 with distilled water and lye mixed with distilled water...and lots of distilled water rinse buckets.

My test piece is in right now and if I get this figured out I will be doing the wheels, frame and deck on my siamese twin.

Here are a few pics of the parts and the set up.

I will follow up in the projects area when I get going on the parts for the Siamese twin.

I also am doing some powder coating now...

 

[zeeprogrammer]

Very cool Bob.
I suspect I'll get into anodizing some day in the future.
Tell me more...what is the 2nd picture about? Is that after anodizing?
Details! Color(s) etc.
Powder coating too? Details!

Thanks.

 

[ksouers]

I'm interested, Bob.

I'd really like to see how it turns out. What are you using for dye?

 

[Jeff02]

A few How To links

http://www.focuser.com/atm/anodize/anodize.html

http://www.mini-lathe.com/anodizing/anodizing_aluminum.htm

 

[deere_x475guy]

Thanks Carl,
Jeff has posted the two links that I have gone to and I printed out the focuser page and binded it.

Ksouers, I am using Rit dye.

Unfortunetely the part for some reason did not take the dye. The aluminum wire took it just fine. I suspect that I may have used 2024 for the wheel split coller and maybe that is my problem. I had a pretty steady draw of 2 amps and the voltage settled in around 13.5. The part was nice an gray looking and was just starting to get a tinge of yellow. I need to do some research tonight and try again in the morning. I will probably strip the anodizing off this part and see if I can get to take tomorrow.

Carl, my first powder coat part came out fine and I will start a seperate thread on late later...right now I am starving and need to get a bit to eat. Tomorrow is my birthday...(57 years young) and I hope to have the whole day to myself..

 

[zeeprogrammer]

Happy Birthday Bob.
Looking forward to seeing the thread on powder coating.
I know what 57 is like. It's not bad. So far.

 

[GailInNM]

Happy Birthday Bob. I think I still remember what 57 was like. ;D

If your anodize bath was too warm then the part will not take dye. Dye temperature needs to be cool also. It's worse on 2024 and 7075 than the other alloys.

A plastic bag full of ice cubes to keep the bath down to less than 70 degrees F will help a lot.

Gail in NM

 

[deere_x475guy]

Carl and Gail...thanks!!..I just got back from a backpacking trip on South Manitou Island with my wife, olderst daugher and her husband....I kept up pretty well so guess I might have a couple years left.


Gail, you may have pegged my problem....I measured the mix temp at 86 degrees and the part at 89....

I will put the part back in the lye mix to strip the anodize layer off tomorrow and try it again...this time with ice handy.

 

[bearcar1]

Yes Bob, you must maintain the acid bath temperature to 70* for optimum anodization to occur. Also carefully monitor the PH of the bath as that too should be kept constant. Though the process itself is pretty straight forward, there are many things that need attention to get the desired results. Anode areas and types, amperage rates and on and on the list goes. Have fun and be safe, splash goggles and all that.

BC1
Jim

 

[deere_x475guy]

Thanks Gail, yes goggles...face shield...a baking soda bath just in case.
The wire took the dye so it must be that the 2024 is more sensitive to the temp than the hardware store aluminum wire...oh boy.....I love a challenge. I am off to Meijers to pick up a fish tank bubbler.

Funny I figured powder coating was going give me problems...


Edited to fix my spelling....duh

 

[deere_x475guy]

Here is a pic of the failed part. Carl the photo in one of my posts farther up were after I had buffed out scratches.

Gail, just another thought, could it be that I didn't let this stand in the lye bath long enough to eat off any of the waxes that might have been left over from the buffing in addition to the acid temp? Also everyone seems to recommend a washing with Dawn dishwashing soap and used Joy...

 

[Kermit]

What method of 'connection' are you using?

Maybe try a more robust physical connection to your part? Aluminum will oxidize immediately in air forming an electrically insulating surface of aluminum oxide and given a path/circuit to follow, more electrical current would leave from the 'part hanging' wire to the low resistance liquid than would cross two oxidized surfaces of small surface area(where part contacts wire)

A small alligator clip pressed firmly down so the teeth penetrate to virgin, unoxidized aluminum? Perhaps?

OR it could just a be a pH problem as previously stated. :-\



Nice to see someone trying this. We will get some good first hand information and reliable methods when you get this thing fingered out!

Kermit

 

[BobWarfield]

I gotta try some anodizing when I get a chance some day. Your first photo reminded me I have that exact same anodizing "power supply", LOL!

I bought the guy's book that runs the focuser site. It's really good information.

Cheers,

BW

 

[tgss2000]

What method of 'connection' are you using?

...
A small alligator clip pressed firmly down so the teeth penetrate to virgin, unoxidized aluminum? Perhaps?

...

Kermit

Just make sure it's an aluminum alligator clip

Tom

 

[deere_x475guy]

Ok gang....I am happy to report the second attempt was a success.....

Unfortunately I changed so many things I am not real sure what cured it...

• Cooled acid temp to 70 + F
  
• Increased concentrate solution on Lye and increased time in solution (10 minutes)
• Heated dye to 135 degrees vs 110 microwaved solution(Part was kept in dye 10 minutes
• Heated dye to 135 degrees vs 110 microwaved solution(Part was kept in dye 10 minutes
• Added air bubbler

I think the real fix was the acid bath temp. I noticed that the amp draw dropped to below 1amp and finished at the end of 1.5 hours at .58 amps and. I also noted that when turning the bubbler off the amps raised from .8 to 1.3. I know the first attempt was around 85 degrees F. and amp draw was pretty consistant at 2 amps.

Below are some shots taken during the whole process....

Built the bubble. 1/16 inch holes were drilled along the length of the 2 bottom pipes at 90 degrees apart so that they were pointed 45 degrees from horizontal.

Here is a shot of the setup:

Here is my shop stove/oven hard at work...at can't believe how much I have used this thing now. The dye was kept as close as I could to 135 degrees and the pot next to it is boiling ready to seal the part. I held the part in the steam for about 5 minutes then dropped into the boiling water for 30 minutes.

I will be doing doing the 2 flywheels and the other collet all at once now and will post pics on how they have come out.

 

[zeeprogrammer]

I am happy to report the second attempt was a success.....

Congratulations!
I think knowing how to anodize is a handy skill.

 

[deere_x475guy]

Thanks Carl, I really got a lot of satisfaction learning to do this and the powder coating..same as I get when I have nicely machined something....you know the high I mean..

 

[deere_x475guy]

Yes Bob, you must maintain the acid bath temperature to 70* for optimum anodization to occur. Also carefully monitor the PH of the bath as that too should be kept constant. Though the process itself is pretty straight forward, there are many things that need attention to get the desired results. Anode areas and types, amperage rates and on and on the list goes. Have fun and be safe, splash goggles and all that.

BC1
Jim

Hi Jim,
Your right, and I will be looking for a ph testing kit next time I am at the grocery store. I was there today but didn't give the PH a thought

 

[deere_x475guy]

What method of 'connection' are you using?

Maybe try a more robust physical connection to your part? Aluminum will oxidize immediately in air forming an electrically insulating surface of aluminum oxide and given a path/circuit to follow, more electrical current would leave from the 'part hanging' wire to the low resistance liquid than would cross two oxidized surfaces of small surface area(where part contacts wire)

A small alligator clip pressed firmly down so the teeth penetrate to virgin, unoxidized aluminum? Perhaps?

OR it could just a be a pH problem as previously stated. :-\



Nice to see someone trying this. We will get some good first hand information and reliable methods when you get this thing fingered out!

Kermit

Kermit thanks for the thought but I am pretty sure it was the temp..all good suggestions though!

 

[deere_x475guy]

I gotta try some anodizing when I get a chance some day. Your first photo reminded me I have that exact same anodizing "power supply", LOL!

I bought the guy's book that runs the focuser site. It's really good information.

Cheers,

BW

I was worried about the amp out put but it worked well.) Glad to get some feedback on his book...I was wondering out how much value it had....I might just order it now...thanks Bob.