Can anyone recommened a compound for lapping hard bronze to stainless steel? When selecting a lapping compound should one use a producted with respect to the harder surface?
Any lapping theroy is appreciated.

I've been grinding metals and glass for more than half my life and prefer the loose abrasives (aloxite) with water than the diamond abrasives, but others prefer the diamond products check these sites (I have no commercial contact with any of these)

http://www.engis.com/

The loose Aloxite powder grade I use is graded at 302, 302 1/2 and 303 for finishing, just got back to work from a customer and leaving in 10 mins, will post more tomorrow.

It all really depends on how much material you want to remove- you need to work down from rough to finishing grades on either choice.

The oil based diamond products are a pain to clean off and tend to "clog", although others may say that the diamond products remove more material, I find that for total control of surface profile the Aloxite and water is better.

Post more tomorrow.

There's few things I'd recommend WD40 for, but lapping is something that it seems to be very well suited to.

There's a lot of times when I'll duct tape a sheet of abrasive to the surface plate, squirt some WD40 on it, and flat-lap a part. What I like is that the paper doesn't tend to load up, and its easy to clean. It tends to act like a beautiful cross between water and oil.