finish

[kenlambert]

I was wondering after anodizing and dyeing with caswell dye and then sealing with caswell sealer my parts always have to be buffed . When I remove them from the sealer or dye they dry with a dull coat on them is theis normal or am I doing something wrong or not doing something at all righ? thanks Kenneth

By the way I am very new at this
don't know how to ad a pic or I would some can bee seen at my website www.lambertsrc.com

[sswee]

Several things can cause the film on finished parts. One of them is the parts drying before they get rinsed when they come out of a hot dye or seal tank. Some use a small dip rinse tank for each hot tank. I rinse my parts over the tank they come out of so they don't have time to dry and then dip in a rinse tank. Another cause is dissolution from anodizing too long or at too high a current density which causes anodizing time to be too long or some thing as simple as not enough aeration or agitation. Without any details on the process, such as part size, CD, time anodized it's hard to help with specifics. Do you have a even film over the parts or streaks and spots.

[kenlambert]

it is even film no streaks and doesn't seem to make any difference on size of item there is one part on the main page of my site 2.25 x 4 " i anodized 80 min. at 12 v and 1.75 amp using this as an example i have done 3 of these parts all did the same and with different colors

[sswee]

The even film and the numbers you gave shows overanodizing. Going by the numbers, your anodizing at a current density of 14 amps per square foot. The time to anodize to 1 mil should be 52 minutes. The optimum coating for good dye qualities is .7 mil would be at 36 minutes. A couple more questions. What electrolyte ratio are you using and what kind of power supply? If you have Excel, check out the sticky on the 720 rule calculator.

[kenlambert]

i am useing sulfuric acid mixed at the ratio on caswell site , i don't remember what that was but it is not frombatteries it was pure and my power supply it is duall 12-24 volt with adjustable amps

[sswee]

You might try dropping to a 5 amp CD for 72 minutes. That will give a peak voltage of 12.5 and a coating thickness of .5 mil according to calculations. You should get a nice dye without the film. The calculations are made using the 720 rule and CC voltage

[kenlambert]

I am going to check that rule and try what you suggest

thanks for the help and I will let you know how it turns out
Kenneth