by RMDJBD » Fri Feb 17, 2006 10:08 pm
Doug
I have been a tool&die maker for 35yrs or more and here is the way you drill lead.
First you need to modify the end of the bit. You need to grind an 1/8th flat on the cutting edge parrell to the length of a 3/8 diamiter drill. It will look similer to a concrete drill, but you can't use a concrete drill because the flute are to narrow to let the lead chips out. What you are trying to do is stop the drill from turning into a wood screw and suck it self into the lead.
Second, you need a good WAXBASE lubricant, such TAPEASE, LPS TAPMATIC or a good bar of soap with a lot of lanolin in it. Oil, WD40,Silicone are no good.
Third, if possible put the hull in a cradle and drill it in a drill press at speeds between 500/800 rpm and clean the drill a lot. If your drill is not long enough you can buy a longer drill at a good hardware store.
Freezing the lead does nothing to help machining. The best way is to drill a little bit and clean.
I showed Reichard how to do it at the Nat's on Dick Reinke's boat when it was over the max water line.
Bob Dudinsky
R.M.D.MARINE