It takes practice. I judge the angle by starting low then raising the angle until I feel it grip. Too high and it will definitely round over.
If you use too little compound then it will stop cutting the steel and just rub it. You only need a small amount but you need to apply it often. Every couple of knives I find is best. The idea is that the compound is just on the surface of the wheel. The particles quickly wear smooth, so you need to re-apply often to keep god sharp particles.
Finally, don't apply too much pressure. If the compound is fresh then it will do the job for you. If it is not then you can be tempted to apply too much pressure thus causing your round over.
Practice these skills and you will go much faster with time.
If you use too little compound then it will stop cutting the steel and just rub it. You only need a small amount but you need to apply it often. Every couple of knives I find is best. The idea is that the compound is just on the surface of the wheel. The particles quickly wear smooth, so you need to re-apply often to keep god sharp particles.
Finally, don't apply too much pressure. If the compound is fresh then it will do the job for you. If it is not then you can be tempted to apply too much pressure thus causing your round over.
Practice these skills and you will go much faster with time.