Arkansas Lapping....I Think I Cheated
And I think I won! I discovered the pleasures of Ebay this year and have been laying in a supply of Arkies to satisfy my budding Hone Acquisition Disorder. This turned up some great vintage hones in need of love. Being of little patience and fewer supplies I decided to lap with what I could lay my hands on. I've gone down the road of wet/dry and was left frustrated. So here's what I did.
1.) Course work. Since I'm a tool and die maker I have access to grinding wheel grit. Aluminum oxide stripped from the wheels by dressing or shaping. I used this on a cast iron surface plate to achieve flatness and /or remove damage from box glue or chips. I have also used silica sand for this with good results. I use it with thin oil to make a slurry adding more oil or grit as needed.
2.) Black diamond paste. Used by mold makers and die makers for initial smoothing of surfaces. This stuff usually runs about 180 to 220 grit depending on who makes it. This is also capable of stock removal on Arkies. Stubborn flaws can be worked out.
3.) This is where it all falls apart because I'm fearsome color blind and can't really identify the grades of paste I'm using at this point except by feel. I do a progression of grits with the diamond pastes using WD40 instead of oil at this point. Diamond paste is like Brylcream, a little dab will do ya'. NOTE!! It is essential to clean everything between grits! The surface plate is cleaned and a small India stone rubbed over it to remove any stray grit. According to various manufacturer's specs I'm going up to around 1800 to 2000 grit pastes on my plate. Cleanliness is essential at this point.
4.) I'm really fond of working one side of my Arkies to a mirror finish and leaving one side a little courser for tool and knife work though I do use the mirror side on knives to do the final finish. The mirror finish is achieved with .5 micron diamond compound on a plate. I have used cast iron, hard D-2, and black granite tile at this point with the freshly ground hardened D-2 being my favorite. Fun to show off my rocks to my friends at this point!
5.) After the stone is cleaned up from lapping and after I'm done patting myself or the back, I go after the stone with a piece of hard D-2 with WD40. Diamond can embed in the stones and it seems the D-2 steel wants to pull them out. Embedding hasn't been a problem for me so far.
I've used this method on a lot of Arkies this year with excellent results. I didn't mention it but I'm referring to hard Arks in the full progression. Got a Washita? Stop lapping on one of the lower grits.
And as a side note on slow stones......I FUBAR fast so a slow stone allows me lot's of time to evaluate and change directions as needed. I can FUBAR slower!
Any comments or suggestions on this method would be welcome. Has anyone else tried this?