Concave blades have got to be one of the most frustrating things on the planet. I bought a pack of Zwickey Deltas because they were advertised as “straight edged” but they’re not–they’re concave. So I bought a round stone to work on ’em but it’s coarse grit so only works to establish a relief. I simply couldn’t find a fine grit round stone so I’m using 400, 600, then 1500 grit sandpaper wrapped around a dowel to finish the edge. What a pain in the ass. It’s taking forever and the results are only so-so at best. How in the hind hair do you guys sharpen broadheads with a concave edge?
After reading your post I sat back to think about your problem . I can’t recall ever in 50+ year of ever sharpening anything with a concave edge .
I think you are on the right road with the dowel and sandpaper . Only I would recommend you use a light oil on the paper and at the end you might use some leather on the dowel . It’ll get there .
They are probably slightly concave due to factory sharpening, and not a good idea for a broad had edge. Just take a file to them and straighten the bevel out, then sharpen as usual until scary.
The Simmons tree shark is a severely concave broadhead and it seems the folks who use them swear by ’em. I remember that Etter on this forum killed a doe with one last season. I’ll look in to the KME method. Thanks folks.
Ben a fella on tradgang put a video up of him sharpening his tree shark with a KME broadhead sharpener and a file. I think it was in the pow wow forum.
jpcarlson wrote: They are probably slightly concave due to factory sharpening, and not a good idea for a broad had edge. Just take a file to them and straighten the bevel out, then sharpen as usual until scary.
J
Ben,
JP is right on the money. Zwicky Deltas are straight edged BHDS but the factory grind is very rough and they need to be filed (straightened) before sharpening them. Most of the job is filing the tip section but you may need to take a little off the heel too. They should be just as straight as a Magnus I or II when you’re done.
When I shot Deltas the first thing I would do is lay a file flat on a bench and draw those heads back along it until the edges were straight. It only took a minutes or two per head.
I have been very impressed with the tree shark and it’s really not that hard to sharpen em. The KME method with the jewel stick is the best. You just really really really have to get a good burr before you try to sharpen.
The video posted above was made by a guy named Chris Spikes. It shows just how easy it is. He’s killed over 100 deer with a recurve and now shoots tree sharks almost exclusively.
I’ve been shooting Deltas for years and found that re-filing (as you have discovered) is the best cure for the concave edge. I create the straight edge by working only on the triple laminated point of the head until I can lay the file down on the blade and cross-file the whole length. Working the whole blade initially may reduce the 1 3/8″ width at the back.
