[kevindtimm]

A number of the pieces that I have purchased have a black phosphate coating that I would like to remove in the hopes of rust bluing (to match the slide).

How can I remove the phosphate coating?

 

[AlchemyCustom]

Sandblast/polish/sand paper.

 

[kevindtimm]

Sandblast/polish/sand paper.

I was guessing that was the answer - thanks very much.

 

[diadem]

Iron phosphate (what you have in a phosphate coating) can be dissolved using strong acids or bases. Unfortunately you need have like 70+% sulphuric acid and an equally strong Hydrochloric acid. Not something you would want to do at home for one or two pieces. If you were in production and got a truck load of parts that were parkerized instead of blued then it might be practical. There is also a process that uses Sodium Hydroxide and Sodium Glucanate but it would be just as nasty.

 

[John Q. Citizen]

Also, not all the parts being sold today that are "blackened" are actually carbon steel. A lot of parts are just stainless that has been treated to look ok on a blue/black gun.

 

[Jim Watson]

A lot of allegedly Parkerized items are just cheap black oxide and would be stripped by rust remover.
Real phosphate conversion coating will require abrasive removal.

 

[Ak-hunter]

I removed mine using muratic acid. Hone depot or lowes in the paint section. Comes in a gallon.

Wear eye, hand, arm protection. Etc etc.

If your using it and don't know how dangerous the stuff could be, don't use it.

 

[1saxman]

You don't have to 'strip' anything. Carefully sand the part to get the finish you want, which of course removes the Phosphate along with the blasted surface. Then start your rust bluing process.

 

[kevindtimm]

You don't have to 'strip' anything. Carefully sand the part to get the finish you want, which of course removes the Phosphate along with the blasted surface. Then start your rust bluing process.

That's my plan, I'm hoping that the parts under the coating are suitable for rust bluing. If not, new parts.

 

[kevindtimm]

I removed mine using muratic acid. Hone depot or lowes in the paint section. Comes in a gallon.

Wear eye, hand, arm protection. Etc etc.

If your using it and don't know how dangerous the stuff could be, don't use it.

IIRC, I used Muriatic acid when I epoxied my garage floor, to etch the surface. Yes, it's dangerous but reasonable care will mitigate most of the danger.