Basic hollow-grinding technique

[Kelly Carlson]

You certainly picked a tough design for your first hollow grinding attempt - but the results are spectacular! Very, very nicely done.

[Bob Sigmon]

Thanks for the compliments but it still needs a lot of work!

This is the first stub tang knife that I have done so I have to figure out the whole handle thing. We'll see. . . . . .

Bob Sigmon

[hammerdownnow]

Gene, you sure are a crotchity ol' coot. I too have spent many a wasted day drifting in the backwater eddies of that endless river called de-Nile. These guys here, who so graciously share there years and years of trial and error experience, not to mention the time, effort and expence of those who have traveled to learn from the old masters are not just trying to lead you down the garden path.They have takin me, in one short year and set me down twenty years ahead. How can i every repay them except mabe pay it forward. These are not (except for me) amatures theorizing on what might work, but the cream of the crop of the custom knife making community coming together to share the love of the art. This is a nice place, with nice people Sure, it is true, you can make a knife with anything from a rock to a CNC, but, nothin beats a belt sander 2x72 for ease of use, repeatable results, fast change of grits, affordability. When it all boils down, I am sure you will come to that conclusion yourself. But, that is not why i started writing this. I wanted to say thanks for that link. I could imajine jaws dropping as mine did when i saw the stuff they offer. 30 inch contact wheels, 132in. belts, water cooled platens! Wow! (Did you see those Rob) Truely a super grinder! With the bolt ons they offer (backstand idler) and a contact wheel you could spruce up your little 4x36 into a serviceable unit. Thanks again, I have added that site to my "drool" folder. Roc link as follows http://www.uselectricaltool.com/products.html
p.s. hey dennis, these things would really keep the dust off your pillows,eh? I havent found prices yet,bet they cost a pretty penny.

[Gene]

You're welcome. . . .

I guess? :confused:

Gene

[hammerdownnow]

Gene, any new thoughts on what you are gonna do? I cut up my two belt sanders to make a big one and haven't got them back together yet. I have not been able to grind for a month and it is killing me. All i ever made before finding this forum was fillet knives from old band saw blades being careful not to over heat them. Since then i've learned to heat treat, and have located sources for materials, what type of steel to use. one thing no one has mentioned to you is the forum has recently moved,in jan. i think. http://pub42.ezboard.com/bcustomknifedirectoryforum Sorry it just came to me that there is a longer history of discussion there. I refer to it often. No wonder you could'nt find much on the subject of grinders. lol. Good luck and see ya in a couple weeks when you finally emerge from that fountain of information. Bye, Roc/Hammer

[Gene]

Thank you Roc -

I'm gonna TRY hollow grinding with the 8" bench grinder.

If that absolutely will not work, I'm jury rig an 8" contact wheel on my mickey-mouse little Sears 4 x 36 belt grinder. I'll lose the platen, but I can buy a new second 4 x 36 with another platen for only $119, so that makes my total investment still $539 less than the next alternative belt grinder.

Yeah, I know all about de Nile. Two years ago my wife and I hads to cross the Nile River seven times in one day, driving around going into prisons in "darkest Africa". No fun at all.

Cheers!

Gene

[hammerdownnow]

Gene, take a look at these.http://www.grizzly.com/products/item...693120&DS_ID=1 G1015. they are pretty cheap and some have reported starting out and continuing with them for many years. Several sourses here make upgrades,like the slowdown wheel Rob Frink makes at: http://www.beaumontmetalworks.com/ He is a nice guy. He will gladly help with anything. He has a page of homemade grinders people have sent pics of. I bought a contact wheel and platen from him. He is johnny on the spot and the quality of his work is top notch.

[C L Wilkins]

Originally posted by Gene
Thank you Roc -

I'm gonna TRY hollow grinding with the 8" bench grinder.

If that absolutely will not work, I'm jury rig an 8" contact wheel on my mickey-mouse little Sears 4 x 36 belt grinder. I'll lose the platen, but I can buy a new second 4 x 36 with another platen for only $119, so that makes my total investment still $539 less than the next alternative belt grinder.

Gene,
I, along with many others, started out there as well. I figured I had more time than money. I found out later that if I would have listened to a number of folks (not unlike some of those that have replied to this thread) that have been there before I would not have experienced as much frustration either and would have been money ahead. I had two different grinders before I "broke down" and bought something that was actually useful. The first was a 4X36, the second was a 2X48. I now use a variable speed 2X72 and I flat grind.

I am sorry to say that I doubt very seriously when everything is said and done that your total investment will be $539 less. As you can see from above, I was of the same mind at one time.

By all means, try the 8 inch bench grinder if you so desire. Just don't hurt yourself. If you have a 4X36, give flat grinding a try. Just be careful.

Oh, by the way. In a prior post you mentioned something concerning the "unusual nomenclature" concerning the use of the term "grinder" for a belt "sander". These can and may be the same machines, HOWEVER a belt "grinder" is used on metal and a belt "sander" is used on wood. A belt "grinder" usually has a higher belt speed than a belt "sander". It is just the opposite for a metal cutting and wood cutting bandsaw. The metal cutting bandsaw has a slower blade speed than a wood cutting bandsaw.

Craig

[Gene]

Thanks for kind recommendations, Craig, but I already knew all that - everybody does.

We all know it's dumb to hollow grind on a bench grinder, and of course you're right, if I had any brains at all, I'd buy a new $1600 BM3 or some such - like you and all the rest of the pros.

But I don't WANT that, Craig.

I WANT to hollow grind this knife on my 8" bench grinder. And I WANT to water cool it slightly.

Just for fun.

And just because most everyone says I can't.

I love a challange. That's why I've already hollow ground the swedge on this same blade - ha ha - with a $15 hand-held electric drill and a 40-year-old bastard cut round file! Wait 'til you see - it's beautiful!

Kinda' like my "new" forge, which just arrived a couple of days ago. An old beat-up, rusted out, hand-crank coal forge! Ha ha and you can't even buy coal here in the state of Florida - I've got to mail order it from Minnesota. How dumb can I get - right?

It's the way I WANT to go.

I'll send you a picture of this knife when it's all finished.

Thank you again very much for your help.

Gene

[hammerdownnow]

Gene, here is a pic of a knife i made on a 4x36. I tried to copy the top knife. It was worn out so i looked a pic for the blade shape. Go ahead, have fun, experiment. It is all about the enjoyment. You need not spend a lot on a grinder. The grizzlys are only 350.95 delivered. I am not a grizzly dealer. I don't even own one. Remember, you asked for advise on grinders. Like i said before, my grinders are cut up waiting for me to put em together. The only way i can throw sparks is with the disk sander off one of them...lol. Here is some more advice. I also have a half built forge, and from what i've learned here it is better, cleaner and easier to use charcoal. I saw some rib cook off guys that had some "real" charcoal that comes in 25 pound bags. It wasnt brickettes it was un- even chunks like you see in the homemade stuff. How bought postin some pics of that swedge you ground? Everyone here loves pics! Later, Roc

[C L Wilkins]

Have fun, Gene!

Now, you've been talking about this ever since the 9th of September, what's the hold up! Lets see some sparks!

Craig

[Gene]

I was afraid you'd ask, darn you Craig!

The holdup is, I only had one teeny old 6" bench grinder, and that is too small a radius for the hollow grinds on this blade, but that cheap little grinder doesn't even pull its 6" stones adequately, let alone 8" ones. And I needed a tougher bench grinder for other reasons also. . . .

So I ordered a nifty 1 hp JET 8" grinder from California. Good quality stuff, made in the USA, unlike the Sears Chinese junk tools I've bought. Must have weighed around 60 pounds.

But the dummies at UPS - like they do with about every other shipment I receive through them - utterly destroyed this massive piece of steel. They had to have thrown it off a five story building!

So the company on the other end is sending me a new unit, and UPS is going to pick up this one they demolished!

In the meantime, I'm working on the warthog handle, guard, bolster and butt plate for this big Persian Fighter.

Plus I'm working on the California Bowie I'm making by stock removal for one of my sons. It's almost ready for heat and cold treat.

Plus I'm running our ministry around the world.

Thanks again for your help!

Gene

[Gene]

The old Cone-loc was a handy tool, and I know some guys who did a lot of hollow grinding with them. But they went out of business.

Now there's a newer and better tool just like the old Cone-loc!

Check it out at http://www.contenti.com/products/abrasives/310-650.html

Cheers!

Gene

[Gene]

We discussed using water cooling for bench grinders and such....

RAM SUPPLY www.ramweldingsupply.com sells a really terrific MIST COOLANT SYSTEM for bench grinders, belt sanders and such. Really cool:

Really works!

It has a little magnetic attachment which rigs anywhere, with an adjustable nozzle which sprays a fine mist of coolant on your grind stone or belt.

The unit sells for $71.25, and you can use their M16 Liquid Coolant, at $15 a gallon, or your own tap water.

Nifty.

Gene

[Ray Rogers]

Mist coolant systems are pretty neat. I use one on my mill and on the surface grinder and consider it essential to have one on these machines. I don't know that it would really be all that useful on a belt sander but it certainly could be used to good effect if you are going to try grinding on a bench grinder.

At the risk of saying the obvious, anyone considering a mist coolant system should be aware that you will need a compressor to use it. There are many different mist solutions on the market and the heavier ones which remove the most heat will require a pretty good compressor. A tiny, thin spray isn't going to remove much heat.

Another thing to consider is the mess they make. Even half a gallon of plain water sprayed around while you are grinding makes a considerable mess when mixed with steel grit and stone particles. I have to use a push broom to get the crap out the door, then a lot of paper towels for machine clean up, followed by a liberal dose of WD-40 to prevent rust on the machines.

Worth thinking about....