PLATING POT METAL...............

[djnice]

Dave i am sure its pot metal........i did a acid test........and it fisses and bubbles on the part..........aluminum does not do that....but like i said flash copper sticks too the pot metal but the acid copper will not stick to the flash copper......it flakes off...........any ideas....

[minord]

I would say that any adhesion problems you're having between the flash & acid copper is due to surface contamination. I don't use SP degreaser on ANY white metal (aluminum, pot, etc.). Soft scrub works the best. And use purple nytril gloves. Latex or rubber will leave a film or deposit on the part and it won't plate properly.

I run my flash copper at 110-120 degrees, and acid copper at 75-80.

Dave

[djnice]

dave, if u have copy chromed pot metal before.....would u mind explaining ur techique on how to do it...step by step......just to try another avenue........and i was running both my tanks @ about 90 but both of them,flash and acid were bubbling, so by Caswell advice try running them at room temp........so with the flash its working well i think @ room temp. but i am not to sure about the acid copper......

thanks once again.

shawn

[minord]

Hmmmm...

OK, here's what I do:

1 - De-grease with soft scrubb, rinse with distilled water.
2 - Sandblast the beegeebers out of it.
3 - quick rinse with distilled water to remove sand residue.
4 - flash-copper @.05adc for 1 minute, then @.03adc for 1 hour.
5 - remove from flash - rinse (distilled water) - acid copper for at least 1 hour at .03adc @75-80 degrees.

Good luck!

Dave

[djnice]

Dave....what is the biggest part u have done(any pics either) and what do u use for a setup......just curious.......and when u flash copper..........is it room temp or higher......well if u use a sandblaster........it leaves pits in the metal right...........do u have to do any filling in(soldering) or does the copper fill it on in....just trying to get a grip on all of it..........from the flash to the acid do u any cleaning or scrubbing or ruffing....or just straight into the acid tank..........
Just to make sure...........these steps are for u doing pot metal right?
Thank you so much

shawn

[djnice]

Dave....if i use a wire wheel........to clean my parts instead of sandblasting......am i having a problem there or not..............just asking.........

Thank you

shawn

[minord]

Hi Shawn.......

I run my flash copper between 110 and 120, and lower my amps to .03 per sq.in.

The steps I outlined in my previous reply are the ones I use, but I left out the nitryl glove. This is important to prevent any chemical residue from being left on the part. Don't feel bad, it took me 4 months to figure this out. Pot metal is probably the worst thing to try plating. Once you get it, it's not too bad to work with, but you'll still get a surprise every once in a while on old stuff.

BLASTING vs. WIRE WHEEL.......

A wire wheel can't open out the surface pores and remove the crud like blasting. this is one of the most important steps. In fact the wire wheel is basically just rubbing down the surface, kind of polishing it, which is burying a lot of the stuff you want to remove and creating more of a problem. Then, if you've used the wheel on anything except pot metal, you compound the problem even more.

The tiny pits created by the blaster get covered by the flash copper, and just a quick rinse with distilled water, and then directly into the acid copper, once you're sure all pot metal has been covered in flash copper. I sometimes go a couple of hours in the acid copper or more to make sure I don't polish through to pot metal when prepping for nickel.

IF YOU EVER BUFF THROUGH TO THE POT METAL, RETURN TO FLASH COPPER FIRST!!!

There's a post by 48Buick in this forum that outlines this all in more detail, you should check it out.

Hope this helps....

Dave

[djnice]

Hey Dave do u use the SP greaser at all............or all u use is Dawn and the Soft scrub.........

Thanks

Shawn

[Coley]

48Buick
I agree with most all that you posted except for the sandblasting to clean up old potmetal.
I have been working closely with a local plater for about 25 years and I always have him chemically strip my parts. It removes the old plating down to the copper and then I can hand finish from there to get the pits cleaned out.

Blasting can cause small bits of media to get embedded in the surface and screw up the plating.

I make a lot of new parts from ZA alloys never blast them before plating...

[48Buick]

Tks for the info.
Im always open to new processes and learning what others have already gone through if their willing to share.
Do you know what he is using for the strip? It sounds like a proprietary type stripper. I have tried all kinds of acids and such but they all attack the base metal and cause more corrosion in the pits. Thats why I have stuck with blasting thus far.
If theres a better way PLEEEAASSEE let me know.
Tks
48 Buick.