Hazeing question when polishing??Help

[mpierich]

Originally Posted by chcustom

Good point mpierich, just today we did a polishing job on a set of triple trees and started out with 240 grit. They were already fairly polished but just had a few deeper scratches. It really all depends on the condition of the metal at the start. Some of the old Triumph and Shovelhead covers that we have done had 1/8 to 1/4 inch deep gouges in them. At that point you really have no choice but to start at 80 sometimes even 40 or 60 grit

Yeah, my last piece I started with 320. I often use 80 for isolated areas. And I have sometimes gone first to the angle grinder to remove lettering and unwanted bosses - the main thing is, anyplace you don't need a heavy grit, don't use it. I guess my comment was to say that for smoothing an extensive sand-cast surface, for me the 120 is plenty fast.

[UncleJimmi]

Hi everyone, this is my first post here as I just stumbled on the site today.
I have 20+ years polishing all types of metals and many plastics.

Bewsted, Using the first method you described is the way I have recommended
to costumers that want to do it them selfs, accept i don't recommend any power tool at all.
If you truly got all the way to 2000 grit then cream polish and a rag will take it from there.
I think you probably have had the valve cover very close to as good as it gets. Cast alum is often as you described, many times you can even see rivers of density (i call them), shiny veins of brighter metal in the clouds of a casting.
I bet if you work some extruded 6061 the same way you did the valve cover
you would see the difference is in the metal and not your work.

Now you can kick back and have a beer, you did a good job
NEVER polish impaired!!!