grinding a double-edge curved blade - anything different need to happen?

[crimsonfalcon07]

Just wondering if, when you grind a leaf-shaped blade, you typically change grind angles or anything at the thinnest points along the blade. Seems to me that if I grind like normal, I'm going to end up reaching the center line a lot sooner at the thinner parts of the blade. I'm shooting for a flat grind to the center; trying this one out for fun and to see what I could learn from it, but I thought I'd see if anyone had any tips.

 

[Frank Niro]

Mark the thickness you want your edge to be and grind to that edge all along. That will give you a consistant thickness at the edge.

 

[insanity]

I like to grind the area with the largest width first and then work into the other areas.

Wayne

 

[Stacy E. Apelt - Bladesmith]

As said by Frank and Wayne, work fro the edge toward the center, from wide to narrow, and from thick to thin.
A blade like this project is a good candidate for using files and leaving the grinder turned off. If grinding, use slower speeds, fresh belts, and watch out for gouges.

 

[crimsonfalcon07]

Thanks for the advice guys. I went ahead and did some experimentation. Turns out that I had it backwards. The thin waist of the blade ended up being thick when I kept the grind even. I ended up taking it down partway with machine tools, then finished it with files and sandpaper as much as I could. I think I need more files though; I only have a few, and even the finest one I have (which is still coarse) gouges the heck out of the steel. So I had to finish it really carefully with my grinders. I was smart this time and made sure I traced the blade shape precisely when I went to grind out the blank, so it came out better than the absymal failure I had last time--that was UGLY. But it turns out I'm not so good at getting the grinds to meet precisely in the center. I think that's going to take me a jig and precise angles before I get the feel for it.

Here's it started out some:

Refined a bit more, cord wrap isn't staying, just put that on for more comfortable grip while I was grinding and sanding and all, and to test balance. It's got to be able to move, after all.

After I get it out for heat treat, it's going to get the full handle covered in some sort of scales. Trying to decide if I want to try micarta, or just pick up some more cocobolo, which I can get locally for a good price.

It's 18" OAL, 1/4" thick, with a blade that's 11.25" long. That makes it a bit shorter than a sword, but pretty long for a knife. So should I have it HT at low 50's RC, or closer to 60 RC? The Steel FAQ suggested low 50's for swords, and higher 50's for hard use knives.