Why buff knives?

M

Mahoney

Joined
Mar 8, 2006
Messages
866
After reading in the forum about yet another buffer accident, I thought I'd ask a question that's been on my mind for a few months.

Why do knife blades have to be polished? I can see the reasoning for polishing "Art Knives" but why polish a "user" much past what can be done on a sander? Most of that nice shiny finish will be lost when the first serious edge thinning is needed, if it's not already a bit scuffed up from use.

What about other surface finishes like bead blasting? Do people not like/buy "dull finish" blades? Is it just tradition or is there another reason why knives are polished?
 
The main reasons for polishing are, reduced corrosion, easier cleanup and general appearance.

Buffer accidents, while they can be deadly, are usually the result of improper technique and lack of hands on training.

My worst was last year when I let a customer put me in the position of working on a piece that I had already decided was unsafe. I started to work on it while angry and I nearly died from the results of the accident.

George
 
Good question, for some reason I get lured to the dark side and decide to do a polish, thankfully the experence is so miserable I do not attempt for quite a while longer. I must say that after shifting to sewn wheels I have very little grabbing but there is always a chance for a mistake. I hope I learned my lesson for a long time and will not be in the darkness for a while.
 
Same with handles, I quit buffing them after my close call....so they're not as shiney....I can live with that.
 
george tichbourne said:
Buffer accidents, while they can be deadly, are usually the result of improper technique and lack of hands on training.

George
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Care to expound on this George? What is considered proper technique when using a buffer?

Not trying to highjack this thread but why don't we work on putting a list of do's and don'ts for buffing!:eek::D

I can add this much if you are putting an object into a bind to reach an area, you are more than likely to get the object snatched from your hand!

If you buff above the center point on your wheel you risk having it snatched from your hand, (when using a grinder for a buffer I have removed the guard and moved behind it to lessen chance of having the object snatched from my hand & if it goes it goes away from me)!

In my opinion loose wheels are worse to snatch an object than stitched wheels!

Slower speed is safer that high speed when it comes to buffers
 
At one time, I thought that I had to buff every knife I made to a mirror polish.

While I agree with George on corrosion resistance and general appearance, I found that a "REAL USER" is going to get scratched no matter what finish it has on it.

I take pride in my "fit-and-finish", but my finish now is a hand-rubbed 600-800 grit finish. It still gets scratched up with use, but is mighty pretty when the customer receives it.

Again, I agree with George about proper technique and/or lack of training with a buffer. I "buffed" automobile paint finishes for over 30 years with both electric and air operated hand-held buffers. I learned many lessons the hard way with those darned things.

Now, if a customer ask for a mirror polish, I suggest he try another maker. Been there...... done that..... and have scars to prove it.

Just my $.02

Robert
 
So far the reasons cited are reduced corrosion, easier clean-up, and appearance.

I can't argue appearance, some people like shiny, some don't. My preference is a finish that can take a bit of wear and still look good.

Reduced corrosion is a non-issue with stainless blades, but this might be a reason to buff carbon steel. In theory, rust would have less "foothold" on a polished blade. If rust started however, I would prefer the hand rubbed 600-800 grit finish Robert Dark mentions. It would be much easier for me to repair and blend out the rust spots into the rest of the blade. The 600-800 grit finish might hold wax better than a mirror polish and have an advantage in rust resistance. This could bear some testing.

Easier clean-up is an area where the polished blade could have an advantage. You could fit more bacteria in an 800 grit scratch than a 2000 or higher grit scratch.
 
I have a 3/4 hp 1800 RPM Baldor that I have owned for over two years and never set up because I am afraid of the thing.:eek: With that said, I recently discovered that a 6 inch Home Depot buffing wheel in a decent hand drill will buff/polish up ivory and wood just dandy as long as I have finished it well with sand paper. yeah, it is a bit more work than going straight to the buffer, but I get to keep all of my digits and it looks better than even a 4000 grit polishing paper finish, at least on the ivory. As for my buffer, I will eventually use it, but probably on a very limited basis. Someone suggested a while back that if I plan to use it to buff a blade, I should try screwing the blade to a piece of 2 x 4. The thinking was that if you launch a 2x4, it will be moving a lot slower than a blade and it is unlikely to stab you. Haven't tried that yet.
 
I've buffed a few knives, but won't do it anymore. I've never had any safety issues, I just don't like the look of a mirror polished blade. The blades that I have buffed scratch so easily that I don't think it's worth the effort. I generally prefer a satin, tumbled or bead blast finish.
 
I never have cared much for a mirror polish on a blade and like Robert a 600 to 800 grit hand polished finish suits me just fine. We have a couple of Baldor buffers and on occasion will use them, but most all of our knives carry a hand polished satin finish on the blade. To me it just looks better.

A bead blasted finish to look right needs to be applied over a fairly well finished blade or the scratches will show through. It is not a cover up. It does cause the blades to rust more easily and shows scratches really well.
 
Hmathews said:
I never have cared much for a mirror polish on a blade and like Robert a 600 to 800 grit hand polished finish suits me just fine. We have a couple of Baldor buffers and on occasion will use them, but most all of our knives carry a hand polished satin finish on the blade. To me it just looks better.

A bead blasted finish to look right needs to be applied over a fairly well finished blade or the scratches will show through. It is not a cover up. It does cause the blades to rust more easily and shows scratches really well.
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Craig Camerer has a neat way to reduce the corrosion factor. He bead blasts the blade and then etches it. I had a fighter with that finish and it looked almost like a really fine Parkerizing job.
 
Why not just wrap electrical tape on for handles?
If you are going to be a knifemaker, you should be able to do any metal finish.
Buffers are dangerous, if you aren't careful. So are drill presses, red-hot steel, grinders, and most of the other stuff in your shop.
 
Bill DeShivs said:
Why not just wrap electrical tape on for handles?
If you are going to be a knifemaker, you should be able to do any metal finish.
Buffers are dangerous, if you aren't careful. So are drill presses, red-hot steel, grinders, and most of the other stuff in your shop.
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Amen to that Bill!!!!!!!!!!!!
 
Bill DeShivs said:
Why not just wrap electrical tape on for handles?
If you are going to be a knifemaker, you should be able to do any metal finish.
Buffers are dangerous, if you aren't careful. So are drill presses, red-hot steel, grinders, and most of the other stuff in your shop.
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I would say that if I am going to be a knifemaker, I should be able to do any metal finish that I am comfortable with or that I want to do. If I don't like or am not comfortable doing polished finishes, there's absolutely no reason I have to do one. Period. Saying that I should be able to do any metal finish is like saying any surgeon should be able to perform any surgery. We all have our niches we fall into, and there is nothing wrong with that diversity. I do respect and admire those rare makers who can do absolutely anything with excellence; I'm just not one of 'em. :D

That being said, I completely agree with what I think is the premise of your statement: if you are going to use a tool, know how to use it properly and safely.

--nathan
 
You guys should consider the polishing cloths that 3M makes. You can get great finishes with them although you just have to do it all by hand. However the bright side is you don't have to worry about losing your life while making a knife.
 
Why not just wrap electrical tape on for handles?
Click to expand...

Because handles like these are more fun. But if you like electrical tape, go ahead and give it your best shot. I spent 30 years in the communication business and we used tons of electrical tape. I found the 3M brand held up the best and would recommend it highly. :D

390250973.jpg


380333458.jpg
 
Hmathews said:
Because handles like these are more fun. But if you like electrical tape, go ahead and give it your best shot. I spent 30 years in the communication business and we used tons of electrical tape. I found the 3M brand held up the best and would recommend it highly. :D

390250973.jpg


380333458.jpg
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Holy Hat those are BEAUTIFUL!

:thumbup:

-Page
 
Those carved handles are beautiful, and the carved blade's not bad either...wow, stunning

OK, I said corrosion resistance would bear testing so I started an unscientific test. I took a 10" Bowie out of the armory that had some sheath corrosion on one side of the blade. The blade is "'finest' polished Chinese unknown alloy steel". I polished the clean shiny side of the blade with Maas polish, degreased the blade with acetone, and used masking tape to divide the blade into 4 zones. Two of the zones got sanded with 800 grit paper until there was a uniform scratch pattern and degreased again, and then one sanded and one polished zone both got a coat of Renaissance wax. I left drops of "pure" Los Angeles tap water (typical Ph 7.6) on the blade in all 4 zones for 24 hours.

The results: The unwaxed polished and 800 grit zones corroded significantly and about equally under the drops. The real difference came in the waxed zones. The 800 grit zone with wax had about 50% less corrosion than the unwaxed 800 grit zone. The waxed polished zone had the least corrosion, a small spot about 1 mm dia., and a faint ring.

My conclusion; if you are going to keep wax on a carbon steel blade, a polished blade is probably better. YMMV, this was just a test in the shop, not a perfectly controlled environment, etc. But it's not too hard a test to try on your own.

I admire the skill it takes to produce polished finishes, but I see them so often on knives that are just going to get beat up that I wondered why? Why take the time and risk? So now we have one situation where a polished finish is better but a satin finish may be just as good in a lot of other situations.
 
Mr. Matthews, You made my point perfectly! Beautiful work!
BTW- what kind of comms? I was in Paging and 2 way for many years.
 
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