Basic hollow-grinding technique

[Gene]

Thank you Kelly for your kind reply! I shall look for those grinders you suggest, and I appreciate your help - more than you know!

Osprey Guy, you used up 51 remonstrative words, without granting me the honor of sharing even one tittle of your infinite wisdom with this unworthy and wretched peon. But think how much time and effort - and happiness - you would have spared all of us with only a couple of kind words - instead.

Just the name of one belt grinder.

Two at most.

I'm an old man.

And each moment I miraculously continue to find myself alive becomes more precious than the last. My winter is almost here.

I've been studying these many pages for weeks now, but somehow stupidly missed the belt sander recommendations.

Far more importantly, this site is an amazing wealth of knowledge, and - until now - I have been overwhelmed by the kindness and yes pity which all of these professional knifemakers have been willing to share with dumb new morons like me.

But I promise, Osprey Guy, I shant trouble you nor your forum again with my contemptuous presence.

Gene

[Ray Rogers]

Gene,

I'm sure Dennis didn't mean that in the way you took him to mean it. One reason that I believe that is that he just asked that same question himself only a few weeks ago and received much the same answer from the rest of us. What grinder to buy first is a huge question, as it turns out, and has been answered in tremendous detail many times in this forum.

I bought the Grizzly for $300 as my first big grinder and still think it has the most bang for the buck although it does have limitations. If you can afford more than that look into the Coote or even the KMG that Dennis finally stretched his budget to buy....

[Don Cowles]

Gene, if you come back for long enough to read this, please don't get your knickers in a knot. Dennis told you, rightly, where to find what you were looking for. It is incumbent on you, as a seeker of information and help, to do the legwork. No one here is obliged to re-type old threads for your benefit; we are all volunteers.

Please have the grace to recognize that no one here is trying to give you a hard time. We are all here to help one another, and impugning someones motives does not help things at all.

[Gene]

Thank you Ray!

I'm sorry, although I've been copiously studying these seemingly infinite pages for weeks now, I have not happened somehow to see specific recommendations about budget-cost belt sanders with 8" - 10" appropriate for hollow grinding.

THAT IS WHY I APOLOGIZED - IN ADVANCE - for asking what I assumed had to appear to you pros to be a stupid question, and quite possibly off thread.

I apologized in advance, Ray!

But - after a man apologizes for his stupidity - it is rude to reply with a 51-word treatise on his stupidity, when just the name of one or two belt sanders would have solved the entire problem.

Thank you for your recommendation and patience.

I shall not be back on this forum.

Gene

[Coutel]

Originally posted by Gene


Next time you come to Mayo (or Live Oak) to do your cave diving, Bob, look me up! We even have a secret grotto on our own property, and no one has ever been down in it!Gene

Wow...I know that area,... beautiful....
Great cave diving country...know the OutPost very well!!!

Kevin.

[Osprey Guy]

Gene-

More than once in your short time here, you have taken someone's response or lack of response the wrong way and that simply has got to stop.
You've been a member in these forums long enough and there's something you need to know which you apparently haven't figured out already...We love having you here and genuinely want to help you and encourage you and welcome you with open arms.

Everyone, and I mean Everyone (myself very much included) wants to help out as much as possible. That is what is so incredible about the CKD. The willingness to share knowledge and the extraordinary civility with which we all conduct ourselves.

I would NEVER in a million years remotely consider anything that was less than courteous in my response to you. I think anyone around here will attest that I have long established my desire to engage with and exchange info, and be friendly to all.

My response was simply the very best way I knew to expedite the very best answer to your inquiry. The thread to which you were refered, not only has input from me, a mere novice...but considerable input from many experienced guys with far more knowledge.

If I thought it would be too much trouble for you to simply scroll down and click on another thread for your answer, then I would most certainly have attempted a more direct answer. I swear to you that, as always, I was trying to be as helpful as was within my power!!!

And as a final note...
I've probably observed ever single post you've ever put up here in the CKD and based on what I've seen so far, I want to offer a very friendly word of advice (and for goodness sake please, please take this the right way), you need to chill out,...you seem to have an extremely short fuse...rather surprising considering your calling.

Everyone here means well. It may not always come across that way so I'm telling you here and now, this is something you must take for granted!!! Try and have a little more patience and faith in us and you'll begin to realize just how much we all truly want to help.

Truly, your friend...

Dennis

Yeah Baby!

PS. For your info a number of responses appeared while I was busy typing this one.
As I look back again, it just occured to me that, "old man near death's door" that you are (that by the way, is meant as a friendly ribbing, Gene)...you actually took the time to count how many words were contained in my earlier response. In the time it took to count the 51 words, you could have scrolled down one page to that other thread and back again more than once!

[C L Wilkins]

Originally posted by Will
Coop, I cant' add much to what has been said, I grind free hand edge up, flat and hollow.

The only thing I do diferntly is that I have a small jig( two pieces of o-1 bolted to gether over the blade to keep the pluges even) and I use a blade grinding magnet to hold the blade while rough grinding. When I go to 220 and abouve I just hold it with my hand and slow the belt down.

Dang Will!

We musta gone to the same school!

Craig

[Gene]

It's me, the new dummy here again . . . .

If someone has discussed this before, Osprey or Cowles, I can't find it anywhere on CKD - so kindly bear with me if you would be so kind.

Has anyone had any significant experience hollow grinding with only a bench grinder? And if so, would you please tell me about it? On or off forum?

The hollow grind I wish to make is on 1/4" 440-C, and the bevel is only 7/8", so my calculations tell me an 8" wheel would be perfect.

And, since all I had was a little 6" bench grinder, and since my wife of 40 years would not stand still for a bottom of the line $1800 2 x 72 with an 8" contact wheel, I've ordered a JET 8" bench grinder. And, heck, that dumb little thing is over $200!

The pros I've talked to pretty much agree you just "can't" hollow grind with a bench grinder. But, man, I JUST PLAIN HAVE TO!

Anybody out there ever do it? Any helpful hints?

Thank you very much!

Gene

[Bob Sigmon]

Just a thought,

Do any of the electrically knowledgeable know of a foot control that could be used on an 8" bench grinder to be able to slow it down for better control (like a foredom foot control or a variable speed controller for routers) or is this the wrong type of motor?

Bob Sigmon

Check this link - Veriable speed foot control it is supposed to work with fractional hp AC motors.

Gene - What hp is the grinder that you ordered?

[mike koller]

Craig and Will,

Are the jigs you all use the same size as you want the ricasso?
Mine is,lets me work on the shoulders in the coarser grits with out moving it.

[Schuyler]

Hey Gene,

Don't let all these naysayers convince you that you can't grind blades with a bench grinder and stone. Let me tell you it can be done, if you want to hard enough, and it sounds like you really want to. Desire is half the battle. These other wimps just like shortcuts. In actuality, you don't even need any power tools! Got good files??

I know, because I did it. 20 years ago for the first knife I ever made. Hollow ground 3/16 x 1", 4" dp pt hunter, 01 tool steel. Still have the proof. Now, having said that...and having the benefit of experience doing it both ways (vs belt grinder), I wouldn't do it again! (but don't get discouraged). Determination is good.

If you are determined, I would probably start with something a little thinner than 1/4" in the interest of time. Some other factors:
-The stone will remove material a lot slower than a belt.
-It will run hotter and you will just have to dunk it more in
your handy water bucket.
-It will probably vibrate, or bump more, as the stone is not
balanced as true as a contact wheel.
- You can't get near as good a finish as with belts, so will have
to be content with a rough finish, or spend a lot of time
sanding by hand to achieve a smooth finish.

Something else to consider is that you won't be able to work normal handle materials with the stone either, so you will spend much more time hand shaping the handle. Certainly not insurmountable though.

If you are determined, I urge you to go for it. No better way way to figure it out than by doing it. And, I guarantee, you'll be proud of that first knife when your done too!

Now, let me tell you a little secret- before I even finished that first knife, I saw the error of my ways and bought a belt grinder!!

Good luck.

[C L Wilkins]

Originally posted by mike koller
Craig and Will,

Are the jigs you all use the same size as you want the ricasso?
Mine is,lets me work on the shoulders in the coarser grits with out moving it.

Mike,
Mine isn't. I use the file guide as just a "guide" for the plunge. I only use it when I have a "straight" plunge. When I am doing a plunge with a radius I leave it off the blade.

I have seen a couple of folks that will place the file guide on their blades and use a chain saw file and cut a "radius'ed" plunge first and then grind the blade. What I do is just wear out both edges of the belt with a scrap piece laying around and I am able to get the belt to roll with it running off the side of the platen if that makes sense.

Craig

[Gene]

Thank you very much for your advice, Bob and Schuyler!

Bob, the grinder is 1 hp and made in the USofA. My new Sears Craftsman drill press and 4 x 36 belt sander were made in China, and are shameless junk. My family and I lived over there in the awful PRC for six months!

I'm checkin' into the foot-operated rheostat, Bob.

I thought I was a hero, Schuyler, doin' my hollow grind on a bench grinder - MAN, I can't imagine you doin' a hollow grind with files - WHEW - you get the Golden File Blade Award For the Determination of the Century!

And yeah, I'll be happy with a rough finish and a lot of hand sanding! But I HAVE to do this hollow on the grinder!

No, this isn't my first knife. My I made in '41; this is my third knife, but first hollow grind.

And yeah, Schuyler, I ALREADY "see the error of my ways" (in NOT springin' for a 2 x 72 belt sander), but - bein' a typical selfish wife Dorothy figures I can do it on the bench grinder - dumb female!

Thanks for all your great help!

Gene

[Bob Sigmon]

Gene,

I'm still searching for foot controls that can handle the amperage of the 1hp grinder... I'll let you know what I find.

Bob Sigmon

[Gene]

Did any of you ever experiment with a water-cooling system on your bench grinders? A little water container up over the grinder, with a pet-cock and tube, allowing a little water to drip on the wheel - with a catchment system under the wheel?

Gene