Cast iron prep

[ewmorritt]

I have a question regarding prep for cast iron. The piece we have is right out of the mold. After grinding off the mold imperfections we rough buffed with a sisal wheel and black compound, and it looked pretty good at that point. (We did a pretty agressive buff.) Then, we buffed with a lighter wheel and rouge compound - obviously not shining, but very smooth. This was followed by a 1 mil electroless nickel process, a rouge buff, and it looked nice and shiny. The customer however doesn't like the rough look of the cast iron. They want it to be "smooth". Is there any way to economically prep this (I don't want to spend 3 hours with a dremel tool on each unit!!) so it's "smooth"? It seems to me that older cast parts were dipped in solder to smooth out the mold pitting before plating, is this correct? If so, where would you get things solder dipped and what is the usual cost? Thanx!

[marsfrogie]

I don't know much about plating, but you would be spending hours tying to sand cast iron to a perfectly smooth finish. I think your best alterative would be to find some type of conductive filler/putty and filling the pits. A dual action sander would probably be your best bet if you wanted to try sanding them out. Say, 32grit Zirconia paper. And you said soldering the pits. I think you are referring to "Leading" which was used extensively by the autobody industry in the past. I have heard it is almost a lost art. Like I said, I don't really know much about plating, and am just trying to be helpful.