Anyone else using the Jerimiah Watt quick change edging tools? I just got a set which were recommended by Nigel Armitage, and was really happy with the first couple cuts. That said I found mine dulled very quickly, less than four feet of edging, and I can't seem to get an edge on them now. Really disappointed, hoping it's just my blade, and wondering if anyone can help me out with a suggestion for sharpening. I'm thinking I may just have got a bad blade with a poor temper? Has anyone else used t