I have a few questions i.e. can you use other buffs than just the
split laps?
Gerry, absolutely not - not “buffs”. That would be incredibly
dangerous, and not very useful either. Your posture is completely
wrong, for one thing - the way you would address the wheel.
I assume that you should use Tripoli or bobbing compound for the
first round on a hard lap, would you then go to rouge on a med
lap?
I could say that there are dozens of wheels and hundreds of
compounds and people use what they like, which would be true but not
very helpful, eh?
There is the MX wheel and I’m sure it has competitors. That’s like
an abrasive cutoff wheel made as a lap. They are expensive,
incredibly aggressive, and extremely wasteful. Also quite dangerous
because of the aggressive grit. They are for production shops
grinding hundreds of rings who also have efficient scrap collection
systems - we don’t use them here, but just so you know.
What we do use is a hard lap with GreyStar, which is a form of
bobbing compound, and a medium lap with white rouge. We also have a
much-worn soft lap that’s about 4" diameter now which is gentler
with rouge for a softer polish. I guess you could use red rouge, but
I got out of the habit of using it at all long ago. White rouge is
faster and good on a lap. I would think that Zam would do well, too.
It’s no different than a polishing lathe - whatever floats yer
boat… Rock-hard laps are useful, but they’re pretty unforgiving -
ditto for soft laps, as they are so soft they can defeat the whole
purpose of lapping.
For platinum I’ll sand with emery, use the GreyStar, go to the
muslin buff with White Diamond just for an intermediate grit, go the
the medium lap with white rouge and then final on a cotton buff. It
sounds laborious but it’s faster than just using wheels, with better
results. I don’t generally do Smurf jewelry but I don’t like hard
edges, either…
Some tips:
Get some 60 grit sanding cloth (tougher than paper) - the stuff on
rolls is good - and a piece of 2"x2" or something wood maybe 6" to a
foot long. Wrap a bit of the sanding cloth on the wood and hold it
there (you’ll find a way…) and dress the wheel top, edge and
bottom before you use it. Do NOT use your fingers instead of wood as
it gets hot instantly. This will create a huge mess, but it’s
necessary to run true. Obviously the sandpaper has to trail the
rotation of the wheel or it will cut loose.
Some people like the bevel face down, which puts the edge at an
angle facing you a certain way. I like the bevel side up, flat side
down… BTW, I also like my bench pin flat side up, bevel down…
Whichever way you like it is fine, but it has to stay that way or
you’ll have to dress the wheel again… Some people also get Magic
Marker or shoe polish and paint the top face black, which increases
the contrast of the split. I don’t care, myself, I guess it helps,
some.
Again - the split lap is incredibly dangerous. Take it slow until
you get used to it. It’s no different than a wheel - if the trailing
edge raises up enough for the split in the lap to catch it your
piece will become a missile. Do not argue with it, it will always
win. It will cut your polishing time in half, though, will far
better results, too.