Are buffing wheels directional?

Status
Not open for further replies.
T

Terry_Dodson

Joined
Jul 10, 2002
Messages
839
I have a 6" bench grinder
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39797

and wanted to replace the stone wheels with buffing wheels to help remove scratches from blades and polishing handles. So i removed the stones, went to Harbor Freight and got 3ea. 6" Spiral Cotton Buffing Wheels
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=39405

And i also got some of the black compund since it said:
Polishing compound for hard metals, used for almost any steel–from steel plates to alloyed steel.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96779

Now once i put the buffing wheels on, started the motor, and let it get up to speen then touched the compund to the buffing wheel it started pulling out threads and only clumped the black compund into one small area on the wheel. Some of the threads standing out of the wheel are over 2" long. So i cut them and tried again. Same thing. So i tried another buffing wheel and the same thing. So are the buffing wheels directional or am i doing something wrong? How do you prep a new buffing wheel?
 
To answer your question. No. You are doing everything right. Anything that is directional usually has arrows on it. Your buffing wheels are a little out of round, this is normal. Since nothing on a buff wheel is within a few thousands or even a 1/16 of inch. It is nearly impossible to make it run true, don't try it that is not challenge it truly cant be done LOL. The buffing wheel is just running out of round, that is why the compound is showing in only one spot. It will wear in quickly.
 
Last edited:
It is normal for buffing wheels to shed threads when you start, especially cheap ones. That is how you get a soft surface that conforms and holds compound.

First advice which you will probably ignore, don't use a buffer for knives unless you have experience using one.
second advice which you will probably ignore, don't use that grinder for a buffer for knives unless you have extensive experience buffing dangerous objects on a less powerfull buffer
third piece of advice which you will probably ignore, don't use soft wheels on that grinder for buffing knives unless you REALLY know what you are doing
Fourth piece of advice you are probably going to ignore, unless you REALLY know what you are doing, if you insist on buffing knives on that grinder with 6 inch soft wheels, wear an apron made of 1/8 or thicker steel which covers you from the bottom of your goggles to your steel toed shoes and kevlar gloves

buffers turn knife blades into sharp projectile weapons, that grinder has a surface speed of at least 18 feet per second, which geometry can enhance for launch velocity. A sharp point penetrating skin requires less force than most people have instruments sensitive enough to reliably measure.
The amount of energy stored in a blade flying at 18+ feet per second is much higher than that. If you do not understand how buffing wheels work, you sholdn't be applying them to knives until you have been tutored by someone with experience.
No offense,
I work with buffers every day, and besides the knifemaker, they are the most dangerous tool in the shop

-Page
 
sunshadow said:
It is normal for buffing wheels to shed threads when you start, especially cheap ones. That is how you get a soft surface that conforms and holds compound.

First advice which you will probably ignore, don't use a buffer for knives unless you have experience using one.
second advice which you will probably ignore, don't use that grinder for a buffer for knives unless you have extensive experience buffing dangerous objects on a less powerfull buffer
third piece of advice which you will probably ignore, don't use soft wheels on that grinder for buffing knives unless you REALLY know what you are doing
Fourth piece of advice you are probably going to ignore, unless you REALLY know what you are doing, if you insist on buffing knives on that grinder with 6 inch soft wheels, wear an apron made of 1/8 or thicker steel which covers you from the bottom of your goggles to your steel toed shoes and kevlar gloves

buffers turn knife blades into sharp projectile weapons, that grinder has a surface speed of at least 18 feet per second, which geometry can enhance for launch velocity. A sharp point penetrating skin requires less force than most people have instruments sensitive enough to reliably measure.
The amount of energy stored in a blade flying at 18+ feet per second is much higher than that. If you do not understand how buffing wheels work, you sholdn't be applying them to knives until you have been tutored by someone with experience.
No offense,
I work with buffers every day, and besides the knifemaker, they are the most dangerous tool in the shop

-Page
Click to expand...

Well said! Thank you for reminding us How dangerous Buffers are. THEY ARE
THE MOST DANGEROUS TOOL IN THE SHOP.
 
Thanks guys. And thanks for the warnings. i had used buffers a long time ago when i was learning lapiday, but that was years ago. I do not remember any of the wheels i was using then doing what these are doing. I thought it may have been the Black compund. I had never used it before and it seems more like tar than the white i am used to using. I do try to be as safe as possible when doing anything knife related.
 
Richard j, I think that sticky would do the most good pinned at the top of the Shop Talk forum, oh yes, and I think it's a darned good idea.

-Page
 
I want to get a buffing wheel but, you guys are making me scared to try it. Is it really THAT dangerous if you hold the knife with a death grip?
 
DustinHall said:
I want to get a buffing wheel but, you guys are making me scared to try it. Is it really THAT dangerous if you hold the knife with a death grip?
Click to expand...

Yes,
especially since most people get half horse or 1 horse monsters running at 3400 rpm and put 6 or larger inch diameter soft wheels on them which will grab and launch a blade. The buffer in the SAC metal shop at RIT had a piece of steel embedded in the floor under it that had been cut off safe and left as a reminder after it planted itself.
If you are going to approach a buffer with a knife, make sure you can stall that buffer with a blunt piece of metal in an easy grip, always keep the piece in the lower quadrant of the wheel, never tip the top of a piece into the wheel NEVER TIP THE POINT UP INTO THE WHEEL
the wheel will still grab things and try to rip them out of your hands


-Page
 
I'm a newbie, I can't say anything with the weight of experience that the smiths here haven't already said. I can recall some events with just a Dremel and a 1" cotton wheel that I have personally escaped. Just a tiny dremel has taken a blade from my careless hand. Not enough force to embed steel in a floor, but more than enough to maim. Even with a firm solid grip, it can steal control of the blade if used wrong.

The most sobering mistake I made was touching up a knife handle with a lanyard attached. The wheel caught in the cord and turned an 8 1/4" piece of razor sharp O1 into a spinning finger eater. I triple checked to make sure I had all my digits and wasn't leaking blood everywhere.

The thought of 1/2 hp or more and the leverage of a big wheel is truly scary to me.

Gene Martin told me a story about the late Bob Engnath, and slicing the bill of his cap off with a flying blade. Maybe he'll happen along and share it in full with us.

Walter
 
Last edited:
1750 RPM buffers are much safer. Small buffs are safer than large ones-they have less surface speed.
 
Hard buffs safer than soft Keep the tight corners, edges all on the down ward side of the wheel. Even a slightly rounded spine should never have the wheel turning into it when it contacts. Pay extreme attention at all times when buffing. Don't buff anything with sharp blades. Buff first sharpen later.
 
Everything above is correct. I'll add:
Don't use a tool for what it isn't designed to do. A 6" bench grinder, is not the same as a 6" buffer. The shields are gone on a buffer, and they should run at 1700-1800RPM not 3400. The shaft size on a buffer is larger,generally,too.

Forget HF and cheapo buffs. Get a quality buff that is designed to buff and polish metal. They may still throw threads in the first use, but will be last much longer.

As Page pointed out, professional goldsmiths and silversmiths polish all day long. I use tiny polishing wheels .25" wide on a 28,000RPM ,1/4HP flex shaft up to a 12" wheel on an 1800RPM 1HP floor buffer. I treat them all the same. You have to develop an instinctive thought process about the item (blade or ring) being polished and where the edges are, where it is pointed, and what will happen if it grabs.

No matter what you do, sooner of later a piece will grab the buff ( this is part of why they are considered so dangerous). At work I have had rings ricochet off three walls before coming to rest in another room. I have had knives come around the wheel and slap the back of my hand. I have had objects totally destroyed by the impact of their striking the floor or wall.......Does this happen every day - NO.....but when it happens (and it will) it is potentially disastrous.

Wear a good heavy leather apron when polishing. One that goes up to the neck area.
Wear face/eye protection.

Wear gloves designed for polishing (often called metal handling ,or polishing, gloves). I know this goes counter to the advice given by many against working on rotating equipment in gloves. This is another place where buffers are very different from other tools. The object being polished/buffed needs to be firmly gripped and your hands will often be rubbing the wheel. You can usually spot a jeweler by the black fingertips on his thumbs and forefingers. The snug fitting polishing gloves ( I get them by the gross at a safety store as metal handling gloves) allow you to hold the metal and get in where the work is being done. A glove will not snag a spinning buffing wheel, but it can snag a tapered spindle or a threaded shaft end. The way to avoid those problems is to keep your hands away from the areas, and to remove the potential snag points. A rubber crutch tip will fit on a shaft end and make it much more knife and glove friendly. A piece of rubber tubing will screw on the end of a tapered spindle.

NEVER polish a sharpened knife. The only time a sharp knife should be taken to a buffer is the two or three passes to remove the wire in final sharpening. This takes skill and understanding, and should not be done by those without a good bit of buffer experience.
A knife being buffed to polish it should not have had the edge sharpened yet. A slap on the back of the hand with a non-sharp knife stings....a slap with a sharp and polished edge will cut to the bone.

Some mathematics (Page already covered velocity) :
The wheel is spinning at 1800RPM (or, God forbid, 3400RPM). This means it makes thirty revolutions in one second. That translates into one revolution in 33.3 mili-seconds. That is much faster than the speed needed to snap your fingers.
So....a blade that snags the buffer and comes around will be back at your hand in 33.3 mili-seconds.... think you got reflexes that fast????? If you are lucky ( an inaccurate term) the blade will be ripped out of your hand and hurled away from you. If you are unlucky (a very accurate term) the blade will be back at you before you realize it has left your hand.

What should you do???
Think ahead and plan the handling of the blade to limit the possibilities of the blade snagging ,.........and limit the possibility of it coming toward you if it does,....and limiting the damage if it does come toward you.


Now I'll give you one of my famous metaphors:

Buffing and polishing knives is like sex..........
Most people start out doing it by hand.
You are warned about the risks.....and somehow that made it more desirable.
Millions of people (in the case of knife buffing, maybe thousands) do it all the time with no problems.
You hear lots of stories ( usually uncorroborated ) from people about how great they are at it.....as well as how big and powerful their equipment is.
Both are taken up by totally inexperienced people who usually have no idea what they are doing. They are often get advise from people with little or no experience. They rarely heed the warnings of older and more experienced people.
Both become easier and more comfortable with practice. There-in may be the danger of becoming lax in preparation and protection.
The results are usually pleasing, but failure to use protection and planning can result in bad experiences....and yes, people have died from those mistakes.
The results were not usually as great as everyone led you to believe they would be.
As you get older and more experienced, you take it for granted.
As you get older and more experienced ,it take you a lot less time.
As you get older and more experienced, it is less exciting.
As you get older and more experienced you realize you have more control when you do it by hand.
All the above probably won't stop one person from trying either sex of buffing.

Stacy
 
I set my buff wheels up on an arbor run via v-belt. Found that I don't need that blinding speed/power.
 
The key word here is "spiral" or more importantly how you interpret it.

There are two definitions......The first is a continuous spiral row of stitching from the center of the wheel to the centre to the edge of the wheel going around the wheel many times before reaching the edge. This is called a "spiral sewn" wheel.

The second is several rows of stiching in arcs from the center to the edge but never going completely around the circumferance...This one more correctly called an "arc sewn" wheel.

A spiral sewn wheel can operate in either direction.

An arc sewn wheel gets bumpy if rotated in the wrong direction. The correct direction is that where the outer ends of the arcs are backward to the direction of rotation. If the ends of the arcs are pointing forward in the direction of rotation the wheel tries to come apart and feels bumpy when rotating.

Any buff mounted off center will accept compound only on the high spot and thus indicate an off center condition.

George
 
you can mount a blade flat to a board and buff the blade a little safer than holding it by hand. just make a couple of holes in the tang and screw it to the board. make sure it is tightly secured and keep the edge down at all times. you can even put a screw along the outside edge of the handle for added stability.

i'm posting the link to the safety sticky again for thoes that might not scroll up to read http://www.bladeforums.com/forums/showthread.php?t=614065
 
Last edited:
WEAR A RESPIRATOR AND GOOGLES ! AND FACEMASK IF YOU CAN HELP IT !

I learned how to buff on a 6" Ryobi buffer which ran at 3450RPM. At the time, i wanted to buff the junk/black off my blades after they came out of the kiln wrapped in stainless steel foil.

Buffing anything is all about the angle you hole it at...The buffer is less likely to be able to grab anything if you have more less surface space on it. (unless it's a knife edge! Then that is all wrong)

When buffing the flats of a blade, I always stand behind the buffer and hold the blade at approx 10 o'clock and the wheel is turning away from me with the edge also away from me.

If possible, you want to find a buffer with the slowest speed possible. Less likely to grab your knife, ring, etc and will not remove metal as fast if you are using a cutting compound.

Jantz Supply (IMO) has good wheels. A grinder doesn't have much clearance between the two wheels.

Personally I use a JET 10" Buffer running at 1725RPM which is better than 3450...but again, I wish I had a variable speed one.

Having something thrown out of your hand via the buffer is like something being thrown out of a Tornado !
 
What Richard mentioned is about the safest way to buff, and is a good way to start for anyone the least bit uncomfortable working with powered buffers. One word of caution when using this method. Avoid applying too much pressure to the wheel, as this will result in the orange peel affect on the steel.

Go easy, and apply buffing compound often. Use an old hacksaw blade to rake the buffing wheel as it spins, and apply the buffing compound to the spinning wheel. Applying compound often helps keep your work cool and cuts a buff faster, and reduces the chances of orange peel.

If there are still scratches and they don't readily buff off, then go back to the grinder and repeat that step, and then try buffing again. Just be patient when it comes to buffing.
 
most important, DONT TRY MAKING ANYTHING HOME MADE!!!! unless you really want to be an entrant for a darwin award :rolleyes:. buffing blades with an upswept tip are the most dangerous kind of blade shape to buff along with double edge daggers. use caution when sharpening daggers with the paper wheels. the tip area is most important to be cautious around with daggers.
 
Status
Not open for further replies.
Back
Top