New problem

[kbstenberg]

Today I cast for the first time with a Lyman 225646. I had a heck of a time with the sprue puddles not letting go from the sprue plate. It was actually harder to get the sprue puddles to come off than to get the bullets out of the cavities.
The sprue hole is tapered. The top being larger an the bottom being smaller. But at the bottom of the sprue hole it is strait like it was drilled with a regular drill bit. The strait hole is about .050 long.
The way i see it i have 2 options
A Find a metal rod of some kind with a tapered end about the angle of the hole or slightly less . Coat the tapered end of the rod with valve grinding compound. Then spin the rod in the sprue hole until i eliminate the flat hole.
B Take the sprue plate off of the mold. Mail it to someone like Springfield. Have him drill out or polish out the flat hole
Being the frugal (cheap) person i am i think A would be my best option. I am asking for any other ways to fix the strait holes.
Kevin

[BCall]

If by straight you mean it doesn't have a sharp edge at the bottom, then the sprue hole wasn't completely drilled. I'd use a countersink and drill it down until you have an edge at the bottom, then hone the back on some 800 grit sandpaper on a FLAT surface. At least that's what I did when I had one like that.

[hiram]

Kevin-

I have sharpened sprue plates. I turnrd the counter sink or drill bit by hand. Speed is not of the essence. Once it is done, it won't have to be done again. VERY IMPORTANT---- After you have a sharp edge, you will probably have a burr on the underside of the sprue plate. Put the plate, underside face up on a flat, steady surface. Take an india stone or a flat sharpeneing stone and lay it on the underside of the of the sprue plate, now facing up. A few flat, unrocking passes of the stone will remove the burr and prevent scaring of the top of the mold. If you don't have the burr, nothing is hurt, if you did have a burr, you will see a shiny ring around the sprue holes(s) where the burr was ground off. It takes longer to write this than to do it.

[kbstenberg]

Thank you Guys thats what I figured. Hiram i hadn't considered stoning the back side. I have some 800 an 1000 grit paper on plate glass for the flattening.
Kevin

[crabo]

I would start with a coarser paper. It will cut a lot quicker, I just use 80 grit on my belt sander after I do it. So what if there are some scratches, you have some more vent lines.

[onondaga]

Scribble with a pencil on your sprue plate and into the sprue gate depression and hole. The graphite in pencil lead is an anti-flux and will prevent sprue puddles from sticking. Second, use magnification and examine the hole in the gate, the sidewalls of the hole should be parallel with no undercut to trap your alloy. if there is undercut of any kind enlarge the hole to correct with the smallest drill that will do the job and then re-flat the bottom of the plate with a fine Arkansas oil-stone.

The taper grinding sounds good too, an inexpensive tapered reamer from Harbor Freight would do that also and guarantee no undercut.

Gary