I read a thread about blade sharpness the other day, and someone suggested using a portable impact wrench. I was considering buying an air impact but the portable electric sounds like the better way to go for me, because I could not only use it in the shop, but in the field as well, and I really have no other use for an impact wrench. Now, for the dumb part of this question. When you loosen the blade bolts with an impact wrench, or re-tighten, for that matter, is it necessary to block the blade with something, as I do with a 2X4 when I remove them with my 1/2 inch breakover, or does the rapid "impact" break them loose without doing so? Just curious. Thanks.