I've had 3 batches of hardware replated now. Which the first 2 have all turned out good, but I still wasn't happy with the dull luster of the plating. I did zero prep on the first 2 batches of hardware and left it up to the plating shop thinking they chemically stripped all the parts beforehand. Turns out they don't, they sandblast them. The results were OK, but I was determined to get a better quality zinc finish on my next batch of parts. So I purchased a 5lb vibratory tumbler. After some experimenting with medias and solutions, my final recipe was green tumbling pyramids from Amazon and a 50/50 mixture of CLR and water. The secret is just that....the pyramids only work best wet with a solution. After tumbling the parts for 18-20 hours, they came out damn near spotless and in raw steel finish. I had to doctor up a few spots with the wire wheel, but this method sure was easy. And the zinc results paid dividends for sure! As the pics speak for themselves. I spoke to the owner of the plating shop and he simply said, the zinc quality and finish is only as good as the metal it's going on! And after seeing my 3rd batch of parts, I strongly agree. Some people may be against the tumbling method because it's a time thing, but for me, I do the hardware tumbling first thing after teardown, fire it in the machine, and carry on doing other work while the tumbler shakes away in the corner! Pretty happy with it.
After Tumbling...
After Zinc Plating. The seat latch pictured was not tumbled or prepped before plating, and the difference is significant.