In my days as a Die Maker when we wanted surfaces to match we used a product known as Prussian Blue on one part so that when it was put together there would be a mark showing the areas of contact or interference. I want to use a similar technique to fit a couple of gun parts together. Is there a similar product used to fit gun parts?
Prussian blue was a oil based product that really didn’t dry. It made a mess mess and easily got all over everything. I thought of using artist oil paint but wasn’t sure if that would work and how easily it would clean up. Does anybody have any recommendations?