Things I have learned about grinding and Finish Sanding

J

Jellis11

Well-Known Member
Gentlemen, most of this is probably second nature for the majority of you, but I just wanted to share some of the things I have learned through trial and error and of course from a lot of you over the last month with some of the new guys like myself.

GRINDING:
1. Go SLOW and take your time when grinding bevels: The first few blades I ground, I couldn't figure out why I couldn't get a straight bevel to save my soul. What I discovered is that I was trying to grind too much, too fast. I was moving from left to right (or right to left) entirely too fast and creating a horrible smile shaped bevel. When I stopped being scared of my machine and more comfortable with what it could or couldn't do, I would make myself take a nice, slow draw from plunge to tip, holding just a wee bit longer at the plunge, and again the tip and WOW! I started cutting straight bevels! This is not a fast process either (working the bevel down) Just take it slow and make corrections as you go.

2. After making a predetermined "stopping point" for my bevel, I have started bringing my pre HT grind just short of this. At this point it doesn't have to be perfect, but I get as close to that as I feel comfortable with. After HT the steel is obviously harder and more difficult to grind which makes closing in on that predetermined line much, much easier to control and cleaner!

3. Just my personal preference...I have found it easier to hand finish my flats before my post HT grind. This has allowed me to clean up any stray sandpaper marks that may have found their way onto my bevel. Speaking of hand finishing....I struggled with a final finish until I discovered that I was NOT speeding up the process when jumping from 220g to 400g or 400g to 1000g. As soon as I began to use as many increasing grits as possible, (ie: 220-320-400-600-800, etc) my finish immediately began to improve.

4. With my initial post HT grind, after taking the finish to around a 320g I was finding that I was leaving a few "voids" or "divits", so obviously I wasn't getting a nice even grind all the way across. So I would take a marker and color in the low spots and flaws, back down in belt grit and concentrate on those areas...the marker ink was an easy way to make sure I was hitting where I needed to.

I don't want to write a book here, and again, I'm guessing most of you already know all of this...but my game has gotten so much better lately and these are some of the things I struggled with. I just wanted to give back and throw some of this out there for my fellow new guys.

Please feel free to agree, disagree or add to as you feel necessary....In this hobby I think it is important to keep learning!

Thanks for looking!!
 
There will be a lot of those Ah-ha moments! I think things sort of clicked for me at about the 15th knife or so, but then at about 30 even more clicked. As I made more and more, I noticed my hand finishing (fixing) time got a little less and less. As you get comfortable you can experiment more with different kinds of belts and grinds and that will open your eyes even more. I've been kind of out of the game for a while now due to building a shop, so I'll probably have to relearn a few things when I get started back.
 
Those are all excellent points/advice!

As I read the post, I was having flashbacks to nearly every student I have ever taught.....the vast majority of "beginners" think that because the grinder is a "power tool", it can be made to "work" as fast as an individual wants...and even though I try to verbalize the opposite, until an individual realizes that a belt will only remove a given amount of materiel on each pass, it's often confusing.

So much of learning how to grind has to do with each person understanding/realizing that the grinder is a stationary object, and that ANY body movement/motion has a cause and effect. Those "voids or divits" you mentioned are simply a very slight pressure difference applied, either in/out, or side to side, and are generally caused by the edge(s) of the belt(s). The words I use to describe it are "pressure" and "torque".... I've found that if I can relate the meanings of those two words, as it applies to grinding a blade, then it makes a student's life my easier.

What it all boils down to with grinding is that each successive "pass" is to "fix" the previous one, and training yourself to interpret what actions caused whatever "mistakes" your eyes see. I often tell people that a day at the grinder is more mentally exhausting then any other operation we as knifemakers perform...... I've come to the conclusion that if, at the end of a day at the grinder, you're not mentally drained, your missing something....and likely have some blades that you wish looked better. :)

Often times I suspect newer grinders feel like we are blowing them off when we tell them "practice, practice, practice", but that's exactly what it takes to develop the skills necessary to understand what action(s) causes what effect(s).
 
Agreed!!! Especially about the grinder being a stationary object and every move or tweak has a result. I found that my stance had a huge impact on the results as well, so I moved my "catch/sludge" bucket to a spot on the floor where I almost have the put my feet in the same spot every time I step up to the grinder.
 
I would like to include that it is a necessity to remember to tuck your elbows into to the sides,
as uncomfortable as that position is for me, it is by far the best advice I ever got! And once you do
it a few times, you will remember to tuck those elbows! I think this tip is what Ed was eluding to.
Having a stationary machine like a grinder, it is imperative that you tuck your elbows in and any
movements you make, are with your entire body! This will fix your dips and most all beginner boo boo's!
I'm not sure if I'm explaining this well enough so if anyone else, Ed or anyone that can verbalize this
better than I can, I'd appreciate it! I know I too often try to explain something and have to apologize for
writing so much, it got to the point where I had certain individuals complaining to me about how long
my posts were, which is why I haven't been posting for a long time now. Even though I was just trying to
help other makers, it still felt like a kick in the gut! So I just backed away, and hoped I got better with my posts,
so with this in mind, anyone if you can say what I'm trying to say any better please do,
Thanks, Rex
 
I completely agree! I think when your elbows are locked to your sides, you are pretty much on point both vertically and horizontally allowing for much less movement in the "wrong" direction.
 
A wise China man once said, "you must become one with your grinder grasshopper." I believe for one thing you have to be in some kind of "mood", if something is bothering you or your pissed off about something it's not a good time to grind, there's been times I was just about to put a hollow grind on and said to myself...you know, I'm just not in the mood to do this and I think if I do anyhow I'm likely to screw something up, so I just did something else at the time.
speaking of hollow grinding, I once walked up to my wheel to do a grind wearing sneakers...yes, I know all about the safety aspect, right away I noticed just that one inch difference from wearing steel toed work boots changed my stance in front of the machine, strange, but that one inch made a difference...maybe it's just me. I always wear those work boots grinding, it's obviously safer too!

One thing that sticks in my mind is something I've heard a couple times over the years, and that is people bragging about how fast they can grind a knife, the first maker I heard say that forgot to add that his disc grinder had a custom reticulating arm that swiveled to either side of the disc, his small crowd was amazed....that's ridiculous, there is no race with time...usually. I enjoy my time at the wheel, the clock stops for me. it's creation time. it's not the time it took you, it's what your finished product looks like.

The same China man also said...if you don't have the time to do it right the first time, you'll certainly have time to do it over.....grasshopper !
 
Great tip!! Every new maker (or old) needs to check this out!

Jellis11 said:
Agreed!!! Especially about the grinder being a stationary object and every move or tweak has a result. I found that my stance had a huge impact on the results as well, so I moved my "catch/sludge" bucket to a spot on the floor where I almost have the put my feet in the same spot every time I step up to the grinder.
Click to expand...


WHAT A GREAT TIP TO SHARE!

JELLIS11,
Without realizing it, I did the same thing without paying attention WHY I did it!
I just knew my slag bucket was in the way for my feet to be where I needed them to be!
So, what I had to do was move my bucket forward of the grinder, but
Where the sparks were barely making it into the bucket, I had to do several tests,
to make sure I still hit the bucket while I few missed the target, the majority of the sparks
went inside it. Which allowed me to place my feet in a specific spot every time.

Now I've had to deal with a bad knee since I was 22, (I'm 51 now) which sometimes causes me serious problems,
primarily, when bad weather is coming AND when I'm grinding longer blades, especially the chopper
sized blades that I so love to make, sometimes, I've had to stop grinding and try again later,
The reason I included this is because it is a perfect example of what you were saying.
Every time I made a sudden kind of drop-jerking motion, it left a gouge in the blade!
Every time without fail, it made an area that had to be fixed..., somehow! There have been times,
when I first started, that the gouge would be so bad that it could not be fixed, and that was before
I read about this technique, as for where I learned it, what I do recall was reading one of the books
published by BLADE, I want to say is one the 4 everyone starts off with, not that I can recall the name
of it, it wasn't 50 DOLLAR KNIFE SHOP, I do recall that, I want to say it's either Wayne Goddard or Bob Loveless,
that emphasized tucking the elbows in and using a swaying motion, where you DON'T MOVE YOUR ARMS!!!
Only your body! The only thing I remember about foot placement was to get your feel about shoulder width
apart and then work from there, to get comfortable, it stills seems like good information, as you MUST BE COMFORTABLE!!

I'm speaking from my own experiences, if you aren't comfortable and are grinding in pain, it will eventually show up in your blade! It happens to knife makers all the time, but the vast majority of them won't admit any pain caused by knife making, whether it be an old injury that grinding made flair up, or if it's just Arthritis getting worse due to how
rigid you have to keep your body, most definitely a skill you want to learn while younger versus OLDer!
Because being in better shape makes everything much easier, but getting the right information is imperative!
That is just one of the great things about this site, as we freely share our knowledge, for all the Newby's,
(I still feel I'm a Newb, myself, and I've been involved in this a while!) One of the BEST resources you kind find
is in the archives, just use the "Advanced Search feature in the right corner on most all the screen on Knifedogs!
Any question you have has more than likely, been asked, and answers are already waiting for you!
Now I'm NOT saying to NOT ask any question you want, but the guys that are always there answering questions
tend to be appreciative of those that do their homework!

I hope this helps everyone, that is seeking knowledge, surely nobody will complain about how long this post is,
... then again, some people will just COMPLAIN BECAUSE THEY HAVE TO COMPLAIN ABOUT SOMETHING!
SORRY ABOUT THAT, I just can't understand why someone would complain about ME trying to help someone else.
It's utterly ridiculous!I guess the old saying goes, "You can make some of the people happy some of the time but
you can't help all of the people all of the time!"Sounds about right to me!
Thanks, Rex
 
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Thank you sir! I'm glad that I could help someone out! I think its important to always be learning, not only in knifemaking but all aspects of life.

I'm not sure who said it, but to quote: "Watch, listen and learn. You can't knw it all yourself. Anyone who thinks they do is destined for mediocrity"
 
This is a great post. Thanks again. I discovered trying to grind while tired or really not feeling into it the grinding suffers. It's just easier to put the balde down and find something else to do for a while.I have two blades I started yesterday and the bevels were turning out pretty good. I decided to try to finish them today. I had a late night. I just ended up grinding an uneven bevel on one blade so I set it aside and did the same thing on the second blade. I started chasing the bevels and the grinds started to look worse. So I set the blades aside and took a ride on the four wheeler with girl friend and puppy. Got back and grilled some steak. Relaxed now but I have to work tomorow. I'm glad I stopped grinding the baldes can wait.

Jake
 
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