new to anodizing, need help

[frontmandan]

anyone with annodizing experience please take the time to read and suggest a solution to my problem


ok i tried to anno some small parts ( 2 paintball marker feednecks) today and it did't go very well.

i tried mulitple configurations of the power supply, i tried 2 different chargers , and then hooked 2 batterys in series to get 24v and the most current i could pull through it was about .2 of an amp

i dont this can be normal from reading some guides as they suggest regulating the current with light bulbs and im not getting enough to even light 1

suspected problems:
1,
because i live in the uk (nanny state) anything vaguly harmful is pretty hard to get hold of, car garages etc dont keep battery acid because the batterys are filled before they are deliverd to them and the only way i can find to get it is through wholesalers in bulk..

so currently my only source of battery acid is from discarded truck batterys

the first time i hooked my setup up i got it the wrong way round and the ammetter maxxed out (6+ amps, which suggests to me that the acid is fine) but soon as i switched it round the right way round i get a .1

in summary im not sure what to think about my acid supply

2. i wrapped my parts in very small gauge aluminium wire (can used for mig welding i think) i did't manage to get it wrapped particually tight as it kept snapping.

so i think i could have an connection issue but i would have though i would have started out with a decent flow and then it would deminish



Results of my day of annodizing, i managed to dye one of the feednecks but it did not dye black as hoped (i used caswell black dye) it was dyed a fairly odd greenish color which changed purple in the light kind of like flip paint (the finish was pretty raw on that feedneck still had marks from the lathe left on it)

it was also very easy to scratch which suggests a thin layer of annodizing


other details

i washed parts down with white spirit, similar to turpentine

surface area was in the region of 7 square inchs

i used caswell annodize and chrome stripper first

i used caswell dyes

i annodized for approximatly 30 minutes (the part was still bubbling when i took it out)


thank you for reading any help appreciated

[destroyer125]

you want it based on 12v not 24v.....I believe you hook the barrery up to a charger or something...Im not completely sure....get a 3 amp recitifier or something from caswell for the best results or a power source used for CB and Ham radios...or at least....a non automatic battery charger

also....doing a very small amount of stuff at one time is a bad idea

and....was your cathone bubbling or your part bubbling...if your part is bubbling you probably got the connectors hooked up the wrong way....black connector goes to the cathode and red is connected to the piece where the item hangs into the acid

[sswee]

Where to start?
Learn and use the 720 rule. A part 7 sq. in SA anodizes at .22A setting for a 4.5A CD for 80 minutes to get a coating thickness of .5 mil.

The power needs to be regulated somehow. I have used automotive bulbs with success. Many use a fan dimmer switch to regulate the power from a battery charger. The charger needs to be manual not an automatic.

The acid from old batteries is a problem, not that it is not any good but getting the correct concentration of 4.8% by volume. The concentration has a direct effect on its conductivity.

Electrical connections normally don't fade away. They go all at once. Wrapping the parts for a connection will have a high failure rate. A hard wire would be better. Bolting the wire to the part with an aluminum bolt.

The parts need to be super clean. This can be done with many things. A high concentration of dish washing detergent works. The parts must pass a water break test. The water will sheet off all over and not bead up.

After the water break test, the parts should be rinsed with distilled or RO water well between each step. All mixtures used in annodizing should be mixed with distilled water.

Did you warm the dye to 140 degrees?

Just a start. I'll let you cipher through this for a bit. There are a few guys on the forum from your part of the world that may be able to help with problems specific to your area.