We are currently in the middle of a project involving some ebonized oak tops for an office. The oak is very dark and almost black, therefore just about everything shows up on the surface. We have filled all the grain and have been using a National Detroit inline sander through the process to get a very flat surface.
The problem began when we went to rub and buff the product (Milesi two-part polyurethane) to the final glorious shine we found it almost impossible to get the surface to rub out completely as we worked it.
Our process was to sand the surface with 600 grit on the inline sander with soapy water, move on up to 800 grit, then 1000, and after that using a rubbing compound on a DeWalt buffer, then on to a finer rubbing paste, then polishing paste. We have had fantastic results with this same process, but this is the first time it has been used on a nearly black surface, and we are seeing a considerable amount of our tiny sanding marks left in the final finish.
My conclusion is that maybe the Milesi Polyurethan when cured is too hard to allow any necessary rubbing/buffing to be completed to the extent desired. Is this sound reasoning?
Does anyone have any experience rubbing this stuff? Any help would be greatly appreciated. The customer is waiting for the pieces.
From contributor C:
First off you probably are not removing the last grit scratches with the new higher grit. Use a white guide coat. Second I would go much higher with paper before compounding.
Thanks everyone for all your help. I simply began with 1500 on a Dynabrade and went up from there, then it buffed out beautifully. I抦 pretty sure cutting it with the 600 to begin with was just way too harsh for the Milesi product.