Okay, I found a home brew recipe on the web describing how to parkerize. So for the novelty of it I tried it on a few spare garand parts that were pretty well worn.

The mix called for phosphoric acid, zinc pennies and water. So I mixed it and followed the directions and tried a buttplate. It fizzes and bubbles for about 20 minutes and comes out medium gray with a fine grain finish underneath a black runny coating that rubs off. Not bad I figured. So I add another buttplate and a lower band and let them fizz and bubble. About 20 minutes later they have stopped fizzing and I remove them and they are perfect black charcoal appearance with no residue rubbing off. Almost look like they sparkle. So I try again with a new batch of mixture and the stuff seems to wipe off and I still get the gray finish. So I use the same solution again and next part comes out sparkly black. I read that you have to add iron or steel wool to the solution to "season" it and I figure that subsequent parts are taking different characteristics because the previous part acts as the "steel wool"? I am not looking to refinish anything like a rifle or pistol but fiishing old parts seems fun and I like to tinker so should I use the steel wool method? Also I thought the Zinc Phosphate yielded a silver gray finish, which is my first results but then I get what most would consider manganese phosphate. Any Ideas?

TIA

Where does one get phosphoric acid? Are zinc pennies the pennies we all know and love or are they something special, something you'd have to get at a chemical supply store? It sounds to me that to get the sparkling black outcome on what you want, you'd have to treat a sacrificial lamb of a piece first. An ordinary piece of steel or a clump of steel wool ought to do it. I think what you are doing is more correctly termed phosphating as opposed to parkerizing. The finish on my M-16 barrel wrench is very dark gray and sparkles; maybe it is what you have done. It does sound intriguing, in any event.

[ 07-23-2003, 07:06: Message edited by: rootbeer ]

Pennies minted after 1983 are copper washed zinc. Sand the slat or melt them and skim the copper off. Phosphoric acid is found at The Home Depot as rust remover in a spray bottle under the brand name "Krud Kutter" The must for Rust. Measure 8oz of it into a SS pan heat up to 120 degrees add zinc discs let fizz for 5-10 minutes. remove the coins, add 24 oz of water bring to a slow boil add degreases parts and viola! Just seems I need to pre-treat the solution with steel wool first to get the black charcoal finish.

how many pennies do you use? is the solution reusable after it cools down? inquiring minds want to know.

The parkerizing solution is not entirely hydrozincphosphate, a little bit of iron(or manganese) is the norm. So yes, the previous treatment leaves some iron ion in it to make the next treatment more appropriate.

Here in Canada, we don't have zine pennies, but do know that traditional dry battery shell is made of zinc. When I was a kid(not that I am very old now) I used to peel the zinc off SPENT batteries and put them in acid to watch them bubble, but the true purpose is to collect hydrogen, an interestingly explosive gas .