All set up and nothing happening

[kickn]

With all your great help (and I meant it when I said I would send you a thank you on my first success! it won't be much but I have a few neet things around here I used to sell - just PM me) - anyways I'm sure I'll get there.

I'm not so worried about the connection as I can actually screw it to the part. I have places that aren't finished surfaces. I'm assuming that if I used a titanium screw that I could re-use these?

On the finishing side - my initial thoughts where to beadblast the part - but thats a bit time consuming. I had someone mention a while ago that it could be etched to achieve a similar 'matt rough' finish. Has anyone had any success with that process?

Thanks again

[Fibergeek]

Doesn't Caswell have a UK distributer? I thought he did.

[kickn]

Is it wirralfospray?

If it is i've already contacted them about dye's and stuff - the other kit I already have.

If its not then please let me know who it is and I'll ask them about some of the other chemcials/etc.

[mcaswell]

Speed Demon Motorcycles
Unit 8 Southlands Industrial Park
Latchford Lane
Bordon
Hampshire, GU35 9JD
UK


Phone: +44 (0) 1420 474961
Fax: +44 (0) 870 136 5288
caswell-europe@caswellplating.com
http://www.youplate.com

[Fibergeek]

Kickn,

I'll address the question you had early on that hasn't been answered.

The pink residue.
Aluminum sulfates, a byproduct of the anodization reaction on aluminum, normally deposit on the cathode. The color should be white or grey. This isn't generally a problem unless you let it build up, and it deceases the conductivity too much. Its easily wiped off of the cathodes if you get it before it hardens, The pink deposits indicate contamination. The electrolyte and the dye should be made with distilled water. Chlorinated water is trouble, the chlorine iron interferes with proper pore formation. You may be able to get away with tap water in the other operations, it depends on your water.

[kickn]

Thanks - that's what I thought it was. I think my mix is totally off right now so I'm not going to worry about it until I fix that. It makes sense that it was chlorine iron or something similar.

[kickn]

Okay I'm back (run....run for your life!)

I'm afraid I'm still having probs. Here's what I've done last test:

1. Grind down sample (approx 0.1 Sq ft) test pc. I did this to remove any oxidation. On one side I polished it, the other I left raw to see what the difference in finishes would be.

2. Cleaned with warm water and house hold dish soap

3. etched in sodium hydroxide for 10 mins to remove any other surface finish @ approx 70 deg

4. rinsed

5. dipped in 5% nitric acid for 5 mins @ approx 65 deg

6. rinsed

7. anodised in 5% sulphuric acid mixed with filtered (reverse osmosis) water. I made sure the connections looked good and was tight. Turned on the psu and adjusted the volts to 12. Turned off the psu. Connected neg to the part and positive to the anode. Turned on the psu and brought up the amps to 0.8 (my calculations suggested 0.6). I left it for about 55 mins during which the volts slowly climbed up to 5v which is where it ended just before I turned it off. I took out the part and rinsed it again (cold water) and then put it in the dye (fabric dye - I know its wrong but its all I have). I then left it there for 20 mins - and nothing!

I know I should have sealed it but the dye just ran off the part anyways. Do you need to seal it while in the dye?

THe result is a pc of ali that clear anodised look. Sort of a milky white appearance. The dye just seems not to want to stick. Does the part sound right otherwise?

I even took a book 'The technology of anodising' which is more of a text book on my hols and had a read through - I just can't see what I'm doing wrong

I'll try to send some pics but I can't seem to get my camera talking to my computer right now

PLEASE HELP

[Fibergeek]

7. anodised in 5% sulphuric acid mixed with filtered (reverse osmosis) water. I made sure the connections looked good and was tight. Turned on the psu and adjusted the volts to 12. Turned off the psu. Connected neg to the part and positive to the anode. Turned on the psu and brought up the amps to 0.8 (my calculations suggested 0.6). I left it for about 55 mins during which the volts slowly climbed up to 5v which is where it ended just before I turned it off. I took out the part and rinsed it again (cold water) and then put it in the dye (fabric dye - I know its wrong but its all I have). I then left it there for 20 mins - and nothing!

I'm not clear on this; in order to anodize the work (part?) is the anode, and is connected to the positive side of the PS. The cathode (aluminum or lead plate) is connected to the negative side of the PS. The anode (the work) is spaced at least 3 inches from the cathode (Al or Pb plate). The anodizing circuit is completed by the conduction of the electrolyte. Is this what you did?

5V measured across the work at completion is way too low, it should have been 2-4 times higher.

If your connections were poor the voltage would appear too high in CC mode. The same poor connections would make the voltage too low if CV mode was used. Are you sure that you set up the PS for CC?

It would help if you would specify the surface area of the work you applied 0.8A to, I need to know the current density you tried to use.

[kickn]

Opps - I had it the wrong way around - I had neg -> part and pos -> tank. - would that completely mess things up?

also - do I need to etch it (thinking about exclusing possible problem steps) if I sand the surface right down?

I'll also try a new cathode - a new pc of aluminum that again I've sanded down.

Anything else?

[kickn]

Sorry - forgot the details about the surface area:

Sq Ft = .1

I put 0.8A which was slightly higher then the 0.6A I had calculated.

This time I will use 0.45A @ 80 mins given ASF=4.5

Does that sound right?