Those turned out pretty nice for a hand fab. As for a hole saw in aluminum, I've never tried them in reverse. I will try that next time I use one. I tend to shy away from them because they are not the most accurate way to cut a hole. The times I've used them, I've had really good luck using some type of cutting fluid to lubricate the cutting edge. It keeps the aluminum chips from wadding up on the teeth. Any type of lubricant will help. WD40 is pretty common in most garages and works pretty dang good."thumbsup"
Thanks for the tips man. Maybe I will have to give a hole saw a shot for the next set.