Zinc Brightener Question

[njpittfan]

I'm just starting out with my copy cad system and i wanted to know how long is the average life of zinc brightener.At this point all im doing is nuts and bolts.I know it says when the finish gets dull add more but can other reasons cause a dull finish?
it just seems like im adding more than i should .I apologize in advance for any info im leaving out.Thanks alot fred

[seanc]

Fred:

The brightener gets consumed faster than you might think. I haven't recorded any data, but I find I need to add some every 100 sq-in or so.

At this point all im doing is nuts and bolts.I know it says when the finish gets dull add more but can other reasons cause a dull finish?

Too little or too much current can also cause a dull finish. How are you calculating your total surface area? Nuts and bolts have far more surface area than you would think just by eyeballing them.

What are your plating parameters? eg, currrent density, temperature, agitation, etc?

Sean

[njpittfan]

Thank you for the help seanc.I was basicly eybally them and figured i was way off in my calcualtions meaning not enough current.I was using 25 ma per sq inch.temp is about 110 deg. I dont know if you consider me stirring the bucket every few minutes aggitaion.I still need to get some for that end of it.i have the 3 amp rectifier that caswell sells.set the volts at 1 volt.Thank you again for your help .I am such a novice at this that im my own worst enemy but im trying.Thanks alot fred

[seanc]

Fred:

Your temperature is way too high. 60-90 is the range, 70 works best.

Despite what the manual says, 25 mA isn't enough. Use 80-100 mA/sq-in.

Nuts and bolts are very deceptive. Eyeballing them can be off by 2-3 times.

There used to be a surface area spreadhseet available here, but I can't find it anymore since the new web-site change. If you want copies, send me your email address (by PM if you want), and I'll send them on to you. They're still not 100% correct, but close enough for starters, and way more accurate than the 'ole eyeball!

Stirring the bucket occasionally works OK. My arms got tired when I started doing lots of parts, so I added an aquarium pump to agitate.

Sean

[mcaswell]

It's here - http://www.caswellplating.com/restgal/surfacearea.xls

[seanc]

Caswell:

Thanks for the link.

Those surface area spreadsheets deserve a prominent place in your downloadable files section. Can you add them? A search, either in the tech support or main page, no longer finds them.

Sean