grinding after heat treating

S

Sammy Mickel

Joined
May 11, 1999
Messages
61
Ed Fowler posed a interesting topic in his book about heat treating your blades thick or oversized. I know he was talking about forged blades at the time. I'm making a blade with o-1 and am ready to try this on a stock removal. I've left the blade a little thick and rounded the cutting edge, or where it will be. My concern is will I over heat the blade in final grinding. Does anyone have any experince with this or any helpful advice?

------------------
 
Sammy, get yourself a 4-5 gallon bucket. Put some dishwashing liquid in it and fill it with water. When you're working the blade, anytime it starts gettin hot, dip it to cool it. Also, fresh belts cut cleaner and better and will help reduce heat. The soap will make the grinding dust settle to the bottom so it won't get on the blade and end up scratching your blade, especially during the finer grinding. There is also a type of spray on cutting fluid I've heard about on the knifelist that MSC sells. It will supposedly reduce heat and make your belts last longer by spraying it directly onto the belt. I don't recall the name unfortunately. Hope this helps! Take care! Michael

------------------
"Always think of your fellow knife makers as partners in the search for the perfect blade, not as people trying to compete with you and your work!"

 
The simplest way is to go by the heat that builds up as you grind. If the blade starts to feel warm, dunk it into a coffee can full of water.If you grind until the steel changes to a dark or blue color, you have damaged the microstructure of the steel.Polishing this discoloration (burnt ) area away will get you back to undisturbed structure.This applys only if you have a small area of "burnt" metal,not if half the blade has changed color.We polish hundreds of metallurgical samples for microscopic examination every week and a slight burning will not cause a change in microstructure beyond a few thousands deep. Cleaning up the discolored ares will almost always be enough. NOTE-this does Not mean that you can grind until the blade turns red hot,only dark or blue. Just go by your sense of feel. If it starts to get warm, dunk and cool and everything will be fine.
 
how bout' mist coolant spray, and water proof belts? anyone ever tried it? heck i might try, just now thought of it.
 
dont know how you are grinding your blades, but the secret is a variable speed belt sander and holding the blade with your bare hands...along with the bucket of water as above.

------------------
http://www.mayoknives.com


 
Thanks for the ideas as for the belt sander, I'm just starting out and using th one at where I work. To make things worse we only have 80grit belt. But I've found that if I take our orbital sanders, which we have 180-320grit, and angle them and feather the blade I can get scrathes from the 80 grit pretty well. From there I can hand rub or buff but I'manxious to try an acid etch. One day I'll have my own tools but the extra work now will make me appreciate them that much more. Anyway I'll let you guys know how it turns out maybe even include a picture if I can. Thanks for the help.


------------------
 
you'll always apreciate machinery if you do stuff by hand first. i've been hand fininshing my blades since the beggining, not becuase of my belt sander, i just think it looks better.
 
Sammy,

Use your bare hands, don't wear gloves, and take your time. As soon as you feel the material becoming even a little too hot, dunk it in the water. Using alot of patience will both, provide you with valuable experience as well as saving you a broken heart. I can't tell you how many times I have completely ruined a nice blade by convincing myself I was in a hurry. They say some things a best learned the hard way, but I hope to try to steer you around some of the miserable mistakes I have made. Burning the heat-treat out of my blades is so aggravating that I now grind all my blades outside, in the cold, barehanded, with a big bucket of water handy.

Sam
 
actually heating is not problem for me I use a dremel moto tool, change bits as needed but then my other hand is always on the blade and tell if it is getting warm, water works well to cool. what do you use to quench when hardening?
 
I plan on using a mixture I either read about in "BLADE" or here on the forums. It's a combination of vegatable oil and wax. The way I hear it you want to heat it around a 100 deg. I may be wrong but I'm going to try it any way. If I get time I'll do it tommorow or saturday. This is my first experience with 0-1. It's a whole lot better than the air hardend tool steel I started off with. I'll post my results.

------------------
 
You must log in or register to reply here.
Back
Top