I think I rounded my edges last time I sharpened them because of sidewall material getting in the way. I only edge (diamond stones) and wax between professional tunes and base grinds, so i haven't purchased a sidewall planer. I do have a fanvy carbon steel file that was a gift. Can I just use it? Will it cut the sidewall and reset the edge, or do I need to pony up for a new tool? And, if so, is a basic model OK, or will it not be precise?