Fillet knife grind problem

[RHaskins]

Does anyone have suggestions on how to keep good control of steel when grinding a fillet knife. I start out not to bad but as blade gets thiner and get to smaller grit belts I just can't keep it from jumping all over the place. Sure would appreciate any suggestions!

:confused:
-Randy

[Ray Rogers]

There have been many discussions on grinding techniques, try the Search key to locate some of them. Fillet knife or not, grinding techniques don't change much.

There are two main keys to grinding: 1) a lot of practice and 2) if at all possible, slow down your grinder when you get to finer grits. Keep ypur elbows tucked in and sway your body to move the blade.

Other than that, I'm not sure what you mean by having the belt 'jumping all over the place'. Good, high quality butt-spliced belts shouldn't do that unless you are applying too much pressure when you use them.....

[Jamey Saunders]

If it's because the blade tends to flex when it gets thin, I remember many moons ago reading in a knifemaking book where the maker used a full-pattern piece of 3/4" oak to back up the fillet blade when he was grinding. Basically, place the pattern on a piece of oak, drill the holes where the handle will be pinned. Cut out the shape of the blade from the wood, then just run some pins through the wood and blade blank handle holes. Grind one side, using the "blade" made out of wood as a backer board. When one side's finished, remove the blade from that side of the oak, pin to the other side of the oak, and grind the other side.

Maybe that'll help?

[RHaskins]

Sorry Ray, what I was getting at was that the thin steel was hard to control against the belt, I'm sure slowing belt speed down would help, I'll have to wait on that till I get some type of varible speed on my grinder.
Sounds like using the board attached to back side of blade is worth trying. Thanks for that tip Jamey.

-Randy

[Ray Rogers]

Randy,

Well then, Jamey's suggestion should help. Making sure your belts are sharp will help too since they cut easily and need less pressure. Persoanally, I never use a backing even on thin, flexible fillet blades - just my fingers. Thin blades heat up quickly and using your bare fingers will let you know in a hurry if the blade is starting to over heat. With a sharp belt and a light touch even a flexible blade won't bend and the heat can be controlled. Like most knife making techniques, this is one that takes some practice. The key to the technique is to support the blade primarily at the platen and not in areas that extend beyond the platen. That avoids excessive flexing ....

[Frank Niro]

Hardening the blade blank before grinding will also help on fillet knives. Frank

[Ray Rogers]

Thanks, Frank, that's very true. Frank and I heat treat our blades before we grind them. I am so used to doing this that I didn't even consider the effect that has on grinding such thin blades but Frank is right, it definitely helps.....

[RHaskins]

Thanks Ray and Frank. I'll surely give that a try on my next fillet.

-Randy

[Jason Cutter]

Just caught this thread. Same problem I had too with my thinner blades.

2 things I have tried work for me...

First, the piece of wood mentioned as a backing for the blade, will keep the blade straight and in full contact with the belt.

Secondly, I have recently made myself a blade grabbing magnet by using 2 flats of mild steel 4inches long, with a small rare earth magnet sandwiched between the 2 flats. It grabs the blade VERY strongly, almost too strongly. If you don't like the metal dust it attracts, this isn't for you.

If you are interested in this, give me an email and I'll scrap together a quick photo of this device for you. Jason.

[RHaskins]

Sounds good Jason, sent you an Email.
Thanks
-Randy