Hi Guy’s,
Using the old ruling pins is a lost art for sure. My old friend Claud McCullough at Sig could use then with ease, I watched him do this many times. He would take the color of dope he wanted and mix some thinner, retarder, and a few drops of methanol until it flowed freely through the pin onto the surface.
He showed me how to do this when I was building one of his old time FF models, they were painted red & black with silver pin stripping. He applied the silver pin stripes with the rulIng pin. Also, he never told me how much to thin the dope but kept adding thinner/retarder/alcohol until it flowed smoothly from the ruling pin, I sure miss Claud he was a good friend and mentor.
Later,
Mikey