If you want a really good finish look for MICRO-MESH.  Available in assorted sets from 1500 to 12,000 grit.  Use with water and wash after use and they will last for years.

Russell

Would 3M deburing wheels be any good, available in various Dias, widths and grades. I use them for deburring stainless after machining and then to polishing.

Hi Richard, I used to produce descriptive plaques in cast brass. The polishing process started with a 6″ wide linisher, with I think a 180 grit belt,then 3M unitised discs a woven material and then 3 stages of buffing wheel. If anything is going to round the edges it’s the buffing, this needs to be done VERY carefully. The border of a plaque needed a good sharp and well defined edge.

If using electric power tools be warned of the hazard of fine brass dust building up inside motors and becoming conductive leading to short circuit and failure. Depending on how much work you have this issue can apply to other electrical equipment near by or even in the same room. Noel.

the rounded edges are achieved by an over zealous operator just be a bit more careful, Ihave to admit not having rounded edges and it does make a difference what angles and directions you use on the parts.

Although I don’t often finish casting so smoothly I do finish CNC machined parts where the finishing cuts can leave a series of scallops.

I start with fine files and then needle files for tighter spots. Then onto abrasive, 240 is a bit fine to start with if you want to get the job done in a reasonable time then start with 120 and work through 180 and 240 which is where I tend to stop for painte dsurfaces, if it is say a bright flywheel rin or a crankcase that is going to get bead blasted then I’ll go 320 and 400.

This was cast iron off the machine

Filed and taken to 240

The aluminium was also taken to 240 from a similar starting point, both will be painted so no need for more but Garyflex blocks are also quite good when you run out of grits on cloth.

I quite like the Hermes “JFLEX” as it is not too stiff and the abrasive stay stuck to the cloth where as the cheapstuff it just drops off. For flat areas I tend to hold a strip along the length of a 6″ file and more curved work a longer strip use in “shoeshine” fashion works well.

This crankcase was hand finished with grey Garyflex after files and cloth to a nice satin finish.