Looking at doing some hobby gunsmith finishes. Will NOT be doing any collector firearms or bubba jobs. These are various salvaged guns that have either no finish or are rusted.

With that disclaimer, inquiring about the differences in magnesium phosphate, zinc phosphate, and OSPHO brand phosphate solution (45%).

And is OSPHO a viable solution to use? I ask because at the company I work at they will sell at cost to employees. Good to use, or a waste of time?

Thanks.

Manganese phosphate will give you your deepest crystalline structure. Let's it really absorb what ever oil you decide to dip it in.
We always used DuLite oil. Consistency of water. Soaks in fast and the excess drains off very quickly.