Al, Never heard of Biros, but then I don't go looking about in Wally World any more then necessary. At the GM&O, we first hand scraped valve seats on the locomotive brake valves and then used a polishing compound called "Putz Pomade"(sp) to do a final lapping. GM&O would not buy the Putz Pomade so we got it from a bloke at the IC RR where they kept it for polishing brass doorknobs etc. We made our scrapers by hollow grinding 8" trangular files to a sort of rounded point. Make good scrapers those files do, provided you are careful not to over heat them while grinding. Jesse > Jesse, "Biros" is a brand of ballpoint pen sold by > Wal-Mart, et al, here in the States, and I am seeing > more clearly why Plasticine would work bettter for > keeping the abrasive from going where it was not > wanted while lapping the valve face on the Burrell. > BTW, the best way to do a Gunmetal or Bronze valve > face must be by scrapping rather than lapping, due to > the abrasive wanting to imbed itself in the soft > material? > > Al Messer MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.