Hollow vs Flat

[Rusty Snuffers]

I hope to have a grinder ready by the summer and thought I'd as the first of many questions regarding the actual blades I hope to build.

What are the pros/cons of hollow vs flat ground blades?  Does it depend on the application?  I intend on making mainly hunting blades; skinners, capers, camp knives.  The grinder I'm hoping to build/buy will likely start out looking like this:

     

With the platen attachment for flat grinds.  I appreciate any and all input.

Thanks as always,
Rusty

[akaboomer]

I really like a good satin finished flat grind. I have a large nostalgic streak that makes me gravitate toward the knives I recall around elk camps and on the many outings from my youth. The ones that I recall admiring all had flat grinds.

I can recall seeing my granddad and other adults sitting by the fire touching up edges the night before first day of season. These are some of the things that stick all these years latter.

Chris

[Bladepeek]

I like the flat grind better myself. In spite of the excellent blades that Bob Loveless ground, I think the hollow grind is a bit more fragile. Possibly because my 8" wheel was too small for the width of the blade I was grinding, I managed to get a nice looking blade that snapped in half when I tried flexing it. Looking at the cross section of the blade, it was much too thin in the middle - like a straight razor. Great for shaving, but not much use in the field. I find the flat grind more visually appealing, but also much easier to control.

[Rusty Snuffers]

Thanks for the two great responses.  I hadn't thought of the nostalgic value, Chris.  Good point.

And thanks for the input on toughness, BP.  Good stuff there.

Rusty

[Lin Rhea]

When I first got my KMG, I ordered the 10 inch round wheel thinking I would use it for hollow grinding. I have hollow ground one blade. It seems I favor the flat grind too, although I truely believe that when done well, the hollow grind has it's place in the field just the same as the flat grind.

My original thinking was to use the 10 inch because it would allow me to hollow grind the middle of the blade somewhat thicker especially for wide blades.

When I started getting involved in cutting competitions, I saw the value of flat grinds for my larger blades. But I still say that a hollow ground skinner or caper is a fine tool to carry.

[tippit]

I did a lot of hollow grinds a few years ago.  A good hollow grind is extremely sharp.  I don't think they are really that fragile compared to a flat grind.  They tend to be easier to start with but much more difficult to get a perfect hollow grind.  Joe Keeslar does a lot of hollow grinds on his Brute de Forge blades.  When done well they look really cool.

With that all said, I now do 50 flat grinds to 1 hollow grind...tippit

[Bladepeek]

I'd like to re-state my response. I also see a lot of good applications for hollow grinds. I guess my only point other than the more traditional look of the flat grind is that it is easier for ME to maintain a nice flat than a nice hollow. It can be forged fairly close and cleaned up on a flat platten, or grinding longitudinally up and down the blade. I've seen some master smiths do beautiful flat grinding going up and down on the wheel instead of back and forth on a platten.

When I hollow grind, I don't have a good feel for just how thin that middle is getting. My short coming - not the fault of the grind. I just go with what works for me:-)

[tomsm44]

I know this is an old topic, but I have some questions that are related to it.  I have been making knives from blade blanks for several years but only started trying to grind my own blades this past spring.  I have ground 4 so far using a hollow grind with limited success.  I hadn't considered a flat grind because the blade blanks I was using before were hollow ground.  Would a flat grind be easier to do well for a beginner?  Also, do you guys use any type of gaurds for the flat grind or do you keep everything straight by sight/feel?  

If anybody knows of any tutorials with pictures or videos showing how to grind, either flat or hollow, I would love to have the link.

Thanks,
Matt

[Lin Rhea]

Link sent.

I dont think either one is easy.  

[tippit]

Grinding is a matter of numbers done plus getting help when just starting.  Just like any other sport, you can develop bad habits without a coach.  It takes longer to correct those muscle memory bad habits than to learn with guidance. I know as I have a box of throw aways but don't throw them away.  As you get better go back and try to fix your earlier mistakes.

Try to attend an ABS hammer-in, find a local bladesmith, and Center Cross Instructional Videos are great too.

Note on hollow grind:

It's not that hard once you learn the technique cause the wheel just wants to follow the groove without being forced.  I was lucky in having Joe Keeslar & Jim Siska (New England stock removal legend) teach me.

Note: If you want to see cool hollow grinds just Google Jim Siska.

[tomsm44]

Thanks

[tomsm44]

How would a common bench sander with a 36" belt and disc sander work for flat grinds?

[Lamey]

nothing cuts with a flat grind/convex edge.