Lapping procedures for home made dies?

[littlejack]

Hey fellas:
I posted this on the "Swaging" site, but maybe I can get more information here.
I am going to make me a case reducing die, and core seating die, to make .41 jackets.
Can any of you that do this type of work, give me some tips on lapping the dies out.
I have made a case reducing die for the .41, on my drill press, before I bought my lathe. It works well, but I am going to make a nice 2 die set on the lathe. I polished the inside of the original die with 600 grit wet/dry paper. This worked well, but what would the proper way be. I know that the factories do not have a fella putting wet/dry paper in a slotted pin to lapp out their dies.
Can someone lead me to the proper tool, and the proper lapping compound?
Your help would be greatly appreciated.
Jack

[Chicken Thief]

A lead slug cast in the die and some valve grinding compound?
Some back and forth motion when polishing is issential. Else rings/ridges will form and it will work like an old washing board.

[Willbird]

If you are just lapping a through hole you can get what they call "barrel laps" right from MSC. http://www.mcmaster.com/#barrel-laps/=l9gdse

They make them for blind holes but I have never tried them. There is a bit of trickery involved in using them, you do not run them clear out of the hole on either side or you will get a bell mouth hole. It would be wise to get some extra "barrels" when ordering the lap.

This stuff used to come in a double sided metal can, one side was rougher the other side was fine, looks like it comes in tubes now.
http://www.autozone.com/autozone/accessories/Permatex-1-1-2-oz-Tube-Valve-Grinding-Compound/_/N-2592?itemIdentifier=526806_0_0_

Ahhhh if you do an ebay search for this 2219 VALVE GRINDING & LAPPING COMPOUND FINE/COARSE you will find the two sided container (now plastic) I referred to. I would keep one barrel for coarse one for fine, the stuff probably breaks down into a finer grit quite quickly. If you just do a search for lapping compound you will get a lot of results for Clover, I have used all kinds of grits with good result really. The clover breaks down in use so it leaves a finer finish. You would lap for a round true hole the almost the proper dia, then POLISH for final finish. One job we polished steel and carbide with wooden sticks and diamond compound, you could quite quickly get a 4 finish which is mirror bright. One KEY thing to polishing and even lapping is if you change grits, use a new stick, and clean the hole first with cotton wrapped on a stick or the previous grit will ruin the next stage of the polish.

We had speed chucks to polish, on high speed they REALLY zinged along :-).

[nekshot]

very interesting, I always enjoy learning. Are the valve grinding compounds at Riley's ok or should this 2219 compound be used only?

[Willbird]

very interesting, I always enjoy learning. Are the valve grinding compounds at Riley's ok or should this 2219 compound be used only?I have mostly used clover, and that boiled down to whatever was around in the shop I worked in, maybe somebody else has more input on picking a grade, the clover is silicon carbide which some claim will not embed into the part you are lapping.

[littlejack]

Thank you very much fellas for your suggestions. I do have some of the permatex compound in the tube. I must have gotten the course, but did not see on the tube where it stated course or fine.
Jack

[Willbird]

The cheapest way from what I have read here and there is to buy loose abrasives, and just mix your own as needed with a little olive oil.