Copy Cad still coming out dull grey

[amobine]

I have set up everything perfectly. The bath solution is 110 degrees, I have added the brightner, I am running the piece at 1.3 amps (exactly 9.5 sq. inches of surface area). I let it stay in the bath for about 8-10 minutes.

It came out dull grey again, and it took me quite alot of work to get it shined up. What may the problem be?

[MrPontiac]

Going to sound weird but is your circulating pump working ok?? Also 1.3 amps for 8 to 10 min.?? sounds like a long time to me, almost like your still burning the part. I polish up my parts first then degrease them soak them in my pickle soultion for 3 min. wash them off with distilled water then plate them. Is this what your doing??

[MrPontiac]

I have been finding out also that the temp. of the copy cad electrolyte plays a big roll in the process, when i go above 90 degree,s it seems like all my parts go grey color on me, if i let the temp drop to 80 it makes a world of differance. Also i have been experimenting with my circulating pump, it also makes a differance, if its not moving the electrolyte around well, parts don,t want to plate.Remember i know its a pain but the better the parts are degreased and polished the better they come out, small parts to me are a pain,patience is the no.1 cure.

[amobine]

I am starting to become a bit frustrated. I took both anodes, and polished them to a completely clean state with scotchbrite pads.

I then use a test piece of steel 6 Sq inches, and plated it at .84 amps, 110 degrees, 15 minutes.

It came out a darker dull grey, that had to be polished to a shine again.

I will try your suggestion of 80 degrees and see what happens. I do have the pump on , swirling the solution around.

I DO NOT pickle the parts, what exactly is this, and I don't seem to recall this step in their plating manual.
Thanks

[ggerhardt]

I just got my CopyCad kit last weekend and have been starting at the myriad of fasteners and parts in my Porsche 911 rebuild. All parts have been media blasted so they are not shiny but have a matte finish on them. When they come out of the plating bath, they are a dull gray that polishes up nicely, then I dip in the chromium bath to get the cad-like yellow finish. That's all well, but it is going to be a very tedious process to have to polish each nut, bolt and washer.

What sort of finish can I expect to get? Initially I was not adding the brightender as the manual indicated not to if a cad finish was desired, but I did add later to see if it would, in fact, produce parts with a brighter finish, but it didn't.

I am running at the recommended temperature and current (0.14amp/in^2). I've run parts at lower currents and achieved essentially the same finish.

I guess I'm wondering what sort of finish I should expect. Perhaps I should invest in a vibratory finisher to polish up the parts.

Geoff

[amobine]

I am in the same boat.So far the tech at Caswell has not been able to instruct me how to get a shiny finish, and my parts are not that easy to polish up to a shine.
Let me know if you have any luck solving this problem.

[kxkraze]

Based on my experience, it sounds like the current is too low or you don't have enough brightener.

For current adjustment, what works the best for me is to begin with the calculated current values based on surface area. Then I will begin my plating but I will make sure that the circulation pump is not producing any air bubbles. Look VERY close at the substrate being plated. If you cannot see any tiny bubbles being formed from the plating process, then turn up the current a little. Keep turning it up until you see some very small bubbles -- not a bunch of them, just a few. You are now in the happy zone and you may turn on the air bubbles in the circulation pump if you wish (I don't). If you have the right amount brightener in the plating solution, your zinc will be almost as shiny as chrome in 10~15 minutes. The brightener gets consumed (probably faster than you think) so be sure to replenish your solution if you are looking for a shiny finish.

If you are still not having any luck, then there is one more suggestion that I have. Buy some Blue Chromate from Caswell and buy some Sulferic Acid (battery acid) from your local auto parts store. Mix up some of the Sulferic Acid in distilled water at a 2~5% concentration. Mix the Blue Chromate per the instructions. After you have finished with the electroplate, rinse the object, dip it in the diluted Sulferic Acid solution for about 10~20 seconds. Rinse again. Dip in the Blue Chromate solution for 30~40 seconds. Rinse with Dist. water and dry with a hair dryer. If your part is not shiny, then you never plated it to begin with.

**** REMEMBER ***** The book should be used as a starting point reference for what you are doing. You will need to experiment, learn, and diverge from it to get your optimal results.

[kxkraze]

Geoff,

The polishing of the parts changes how the light is reflected from the part. Think along the lines of the electroplate being like paint. If you use a gloss paint on a rough part, it is still glossy, it just doesn't reflect light like a smooth part does. Same goes for plating.

If plated properly, the plate will be the same "color" no matter the substrate texture. If you want the fastener, bracket, etc. to "Pop" then you will need to polish the surface smooth first.

One VERY important thing to remember is that when you media blast your parts, you significantly increase the surface area. The 0.14 won't even come close. You will need to dial it in to get what you want. The acid properties in the Chromate is what is giving you some shine right now.

[ggerhardt]

Yes, it makes sense that a media blasted part will have significantly more surface area and will demand more current. At the current levels I am using, I am not seeing any bubbles coming off the parts being plated. I'll try your suggestion of bumping up the current until I see bubbles. The thing is that I seem to be getting a healthy plating, its just that its a dull gray. With a light buffing with steel wool it shines up nicely. If I dip that dull gray part in the chromium solution, I get a dull green finish. If I polish it first, I get the desired shiny yellow finish.

But just to note, my parts are not shiny and polished when they go in the plating bath - they definitely have a matte finish from the media blasting. Can I expect to get a shiny finish right out of the plating bath?

Thanks for your help.

Geoff

[seanc]

Considering the other thread where you first posted your problem, I'm not sure now what you're seeing in your "dull grey" parts. Can you post any photos of your parts?

All parts come out of the plating bath w/ a grey/brown film on them. The only way to get rid of it is a post-plate acid "bright" dip. Are you doing that?

Chromates are all acid based, but don't "self-brighten" as much as you'll get w/a separate post-plate dip.

Does your agitation pump have a built-in filter? If so, you're filtering out all the brightener.

Your temperature & current should be just right now, and you should be getting fine bright parts. But clearly something is still not quite right. You should not have to manually polish parts after plating to get them bright.

Check the new photos in my photo album.

Zinc Plating Album

I didn't have to do anything to those parts after plating. The way you see them is the way they came out of the plating bath & chromate.

Of course, preparation is most important. Beyond that, this is the procedure I use:

1. acid pickle (10% muriatic acid solution) - I only do this if the freshly cleaned part has been exposed for more than a couple of hours. It activates the steel surface, and etches away any minute rust which might have developed since the part was cleaned/blasted.
   
2. plate - I use .140 ASI & 100-110º, no problems at all
   
3. acid bright dip - depends on final chromate
   • for clear or yellow chromate, I use 1% nitric acid, it is far superior to any other acid in "brighteneing" effectiveness. Nitric is difficult to obtain, and much more expensive if it has to be shipped. 5-10% Muriatic acid works good, but the part must be dipped a bit longer.
   • for Black chromate I use 5-10% sulphuric acid. Sulphuric is the only type to use w/black chromate.
4. Chromate

Sean