I am sure all you milsurp guys must have some experience in this area. It doesnt take a lot of cleaning to remove a bit of blueing if it had any left. so what do you do?
Well I did some research and the options seemed to be cerakote, which is a bit modern for old milsurps and I was looking to help out a 1916 smle, Parkerizing seemed to be a very military coating although it came in a bit later like for WW2 but that seemed like a good compromise. So I started looking into it the method not too hard and chemicals available from Brownells all seemed good. Then came the stumbling block chemicals pre mixed are not in Australia and a bit hard to come by, at least at first glance.
I then found this site www.caswellplating.com.au they have a chemical mix that at only warm temps does the job of turning the steel black in 3-5 min. it actually turns black as soon as you drop it in. The process like any is to prepare the metal well back to bare metal and free from grease, sand blast optional depending on finish wanted. Then drop in a mix of 1-9 to water of the acid/selinum mix, rinse and then put in a sealer for 24 hours. I looked at the MSDS and it was just Mineral Turps 79% and motor oil 8% so I mixed my own. This was consistent with the Parkerizing method often using WD40 a light oil others using motor oil so I made a mix of about 80/20.
So it was easy enough will let you know the results later and put up some pics. The Black Oxide was a bit $$ at $80 for 500ml so it makes 5L.
I just made up 1L and did the parts separately easier to manage and have stored the used solution as it can be used again.