Pre dip black parkerizing post dip black dye parkerizing.

[Vincent]

Yes. I will do that.

[Vincent]

Attachment 61835

This was a 15 second dip in the sulfuric mix. Then only a short time in the Parkerizing tank. I wanted to see if it changed the color of the substrate. It did.

[Vincent]

Attachment 61837Attachment 61836

I did these parts for a friend. Couldn't find the thermometer so I had to guess at the temp.

Got some nice crystals. Gray is normal. Turns black when coated with clear oil.

[Vincent]

Attachment 61838

I didn't sandblast or clean this bit of Sterling tube before putting it in the dip. No surprise it came out blotchy.

[Topfmine]

There's certainly a change. Did you wash off after the 15 second dip or dunk straight from the tank, just wondered if there would be a difference with the crystallization ie smaller. I think but not sure you rinse the part on the instructions on the original solution before you dunk in the Parkerizing. What Parkerizing did you use Zinc or Manganese.

[Vincent]

I didn’t rinse the parts. Just put them straight into the tank while they were still fizzing.

The crystals grew bigger the longer the parts were left in the tank.

It’s industrial manganese phosphate solution. The plant where it’s mixed is not far from me.

You should be able to find the acids to mix your own pre dip. Our local auto parts shops sell “battery acid.” It’s replacement electrolyte for lead acid batteries. The concentration of sulfuric acid is slightly higher than in the pre dip mix. http://www.batteryweb.com/downloads/ScholleMSDS.pdf Hydrochloric acid and phosphoric acid should be readily available in the UK. They are used in lots of household products.
Household Products Database - Hydrochloric acid
Household Products Database - Phosphoric acid

[Topfmine]

Many thanks vincent for your help and information I will certainly be looking into having a go at making my own solution.

[Vincent]

You are welcome. Try it with zinc Parkerizing and let us know how it does. I would be interested in the results.

[bigduke6]

Thanks for the tests Vincent certainly a big difference, maybe pre dip is the way to go..... will try a few small test bits when I,m home.