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JAG
05-24-2010, 10:10 PM
OK Dogs, I'd like some advice on the finish grinding process after heat treat.

How do you handle the edge? Do you grind down to the finished thickness and then bring the grind up (like the initial grind) ? Do You just grind the full width and put more pressure on the edge of the blade? Hopefully you understand what I'm asking:confused: Any info would be appreciated2thumbs
Thanks!
Jerry

John Barker
05-25-2010, 09:05 AM
Are you asking how to get the edge to the desired thickness before sharpening?
-John

JAG
05-25-2010, 09:20 AM
Hi John,
Yes. When I do my finish grinding it seems that just regrinding the blade is not working because the edge is still too thick. So I am wondering the best way to remedy that? What is your approach to thinning out the edge?

EdCaffreyMS
05-25-2010, 09:22 AM
Prior to heat treating my edges are fairly thick....sometime as much as 3/32-1/8". After heat treating I put on a fresh 50 grit belt, and grind the entire side of the blade to nearly finished dimensions. It's all about what I call "pressure" and "torque". Pressure being the about of force you use to push the blade STRAIGHT into the belt, and "torque" being SLIGHT pressure in an up or down twisting manner. It's not really a motion, but rather just pressure.....inward at the top if you want to thin the edge down (assuming your grinding with the edge up), or inward pressure on the bottom if you want to "walk" the grind towards the spine of the blade.

The trick is to maintain full contact of the blade and belt, and use the "torque" to make the grind move up of down the blade. You want the blade to maintain full contact on the belt, but through the use of "torque" you force the belt to cut more at either the lead in, or the trail out sides. (top or bottom as your holding/grinding the blade)

Let me qualify those remarks by saying that nearly everything I do is a flat grind, convex edge type of grind.
I go to nearly finished dimensions with a 50 grit, then go straight to a 400 grit with only enough meat left that I can remove the 50 grit scratches, and end up with edges that are sharp, or very close to it, by the time I'm done with the 400 grit.

I personally think that trying to get away with as small of an edge bevel as possible is crucial to cutting performance.

John Barker
05-25-2010, 10:09 AM
I leave mine pretty thick to prior to HT around 0.040" to 0.050 depending on the blade. I hollow grind everything unlike Ed, but Ed is right on in his description. You have to keep an even pressure against the wheel laterally while at the same time twisting the edge toward the wheel. Hard to describe. You have to learn to feel it. Just keep practicaing and don't burn up the edge.
-John

JAG
05-25-2010, 10:29 PM
Thanks guys, I do understand what you are both saying. I think what I am maybe doing wrong is not keeping the full blade against the belt as you are describing. I think trying to be aware of that will make a difference. I understand the "torque" aspect and know what it feels like. So I will try to keep the blade on the belt and apply extra torque towards the edge. Sounds easy enough! Ha! Thanks!!

jkf96a
05-27-2010, 01:15 PM
Well said, Ed. I do nearly the same, although not quite as nicely as Ed does :)

whiteeugene
05-27-2010, 04:53 PM
Prior to heat treating my edges are fairly thick....sometime as much as 3/32-1/8". After heat treating I put on a fresh 50 grit belt, and grind the entire side of the blade to nearly finished dimensions. It's all about what I call "pressure" and "torque". Pressure being the about of force you use to push the blade STRAIGHT into the belt, and "torque" being SLIGHT pressure in an up or down twisting manner. It's not really a motion, but rather just pressure.....inward at the top if you want to thin the edge down (assuming your grinding with the edge up), or inward pressure on the bottom if you want to "walk" the grind towards the spine of the blade.

The trick is to maintain full contact of the blade and belt, and use the "torque" to make the grind move up of down the blade. You want the blade to maintain full contact on the belt, but through the use of "torque" you force the belt to cut more at either the lead in, or the trail out sides. (top or bottom as your holding/grinding the blade)

Let me qualify those remarks by saying that nearly everything I do is a flat grind, convex edge type of grind.
I go to nearly finished dimensions with a 50 grit, then go straight to a 400 grit with only enough meat left that I can remove the 50 grit scratches, and end up with edges that are sharp, or very close to it, by the time I'm done with the 400 grit.

I personally think that trying to get away with as small of an edge bevel as possible is crucial to cutting performance.

If you were were working with 1/8 stock how much would you grind before HT?

Calvin Robinson
05-29-2010, 07:00 AM
I use a lot of 1/8" stock and I do all my bevel grinding after heat treat. I profile my blades, surface grind then heat treat then grind bevels starting at 60 grit then go to 400 grit then a 400 grit hand finish. I use Simple Green and water mixed 4 to 1 as a coolant and lubricant, I use a spray bottle and spray it on the belt while grinding, I also use it to wet my sandpaper with while I'm hand sanding.

whiteeugene
05-30-2010, 04:53 PM
I use a lot of 1/8" stock and I do all my bevel grinding after heat treat. I profile my blades, surface grind then heat treat then grind bevels starting at 60 grit then go to 400 grit then a 400 grit hand finish. I use Simple Green and water mixed 4 to 1 as a coolant and lubricant, I use a spray bottle and spray it on the belt while grinding, I also use it to wet my sandpaper with while I'm hand sanding.

Thanks Calvin

What brand of belts do you use I've used some that grab when they get wet especially at the higher grits?

JDW
08-14-2010, 04:29 PM
I use alot of 1/8" stock in 1095 and O1, I take my edge down to .040-.060" pre HT, then finish it after HT, starting with a new 120 grit Klinspore J-Flex and my speed dial on the Bader at 25-30% and dip in water after each pass on the belt.
Dale

son of liberty
09-13-2010, 10:08 PM
If someone was cutting a scandi edge with a file is it OK to heat treat after the edge is near complete or do I have to try and file a hardened edge?