I'd like to hear an expert's opinion on this as well. I had planned to hit the edge of the rotor housing (the surface that mates with the iron) lightly with the orbital with fine grit paper to clean up the gasket (water o-ring) surface.

those irons turned out really nice!

They do look good! Any pointers from a first timer John? I'll be doing this soon as well. My thanks to you and Lynn.

I just followed Lynn's directions. I found that the 180 grit paper went away pretty fast. I ended up using two discs per iron face. I used medium pressure on my electric random orbital.



With the 400 grit silicon carbide paper I found it kept its grit as long as the iron was well flooded with the kerosene. I went at this for a while - maybe four or five minutes. I occasionally would wipe the iron clean with a rag, then flood it with kerosene and go again.



I could have attacked the center iron a bit more I think but the surface looks and feels good to me. Not that I know what I'm looking or feeling for, though. Ha!



I powerwashed the heck out of it at home. Liberal with the soap and water at high pressure. Then a good drying and a drench with WD-40. I'm building the motor this weekend.



Incidentally the irons that came out of my high mile engine are great! Better than the ones I bought in terms of step wear and no measurable warpage. I was going to do the Lynn method on these as well and post them for sale. If anyone is interested let me know!

I have found that using a wetstone and mineral spirits work well to clean the rotor housings. If you have a parts cleaner put the rotor housing laying flat so that one side that would normally face the iron (mating surface) is down and one is up. Place the wetstone in the mineral spirits so it is wet. Then gently run the wetstone around the mating surface of the rotor housing. You are not trying to remove material. It will make the mating surface clean. When you are finished rinse thoroughly with water (pressure washer). Sorry I am not as good as the detailed responses Lynn has. This method has worked great for me for many builds. Again you are not trying to remove any material. Hope this helps.

wow, i was actually hell-bent on sending out my latest side housings to get lapped, but now that i've seen this, i'll probably opt to do it myself. a few details aside, i've been using the methods that Lynn detailed to do the housings on my builds already.



for rotor housings, i usually just spend a few minutes roughing them up by hand for oil retention. i've actually never used anything coarser than 400 wet paper though.