I used this to Bust the glaze on a 68mm bore, in a cast steel barrel of a motorcycle engine. It worked really well - 10 - 30 SAE Oil, 1,500 RPM for a few minutes, left a very smooth set of honing lines. BUT 1: you have to REALLY take time getting th e abrasive out of the barrel after the hone. and 2) I think you may need to run the devices for longer than I did, as the scoring marks were still evident after running in the Bke.
Rating: [5 of 5 Stars!]