I've had to refashion a couple of times. I grind the chisel edge back flat at 90 deg on a slow grind wheel, then very slowly worked the angle back as far as I can without over heating and constant dipping in water.You got to have your mind on what is happening at both edges and keep checking them as resistance decreases when you approach each edge and the tendency is too curve them. Then I just use well fixed grind stones on a bench that is below waste high. The arms hold the chisel with the palms facing down and you roll the wrists as you draw from edge to edge across the stone. If your arms aren't moving along a parallel line with the stone its going to skew and be uneven. There needs to be even pressure with a slight lightening off as you get to each end; its very easy to put too much pressure or not enough on either end. Watch carefully the lines the chisel leaves on the stone. You should be getting STRAIGHT WIDE lines that come up very close to the where the chisel edge is. The Stones I'll level as soon as I depressions start happening. Once you get about half way along sharpening confidence increases. The attention you give when using heavier grit is what makes or breaks. I go to compound honing sooner rather than later as you can always go back to stone if its too time consuming.