Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Aug 20, 2004
- Messages
- 37,722
I have had a lot of emails and PMs about buffers lately, so I though it would be a good time for a discussion.
There are many pros and cons to buffers. The biggest Pro is they will bring a properly sanded surface to a shine quickly. The biggest con is they can tear a knife out of your hand and throw it quickly. These topics have been discussed at length and i suggest using the search engine to look at the past opinions on the subject.
With all the "most dangerous tool" and other talk, the fact is that most knife and machine shops that do any amount of work have a powerful buffer. The thing that makes it a dangerous tool is 50% setting it up right and 50% using it wrong.
Buffing in a Knife Shop:
There are three main things knifemakers buff - blades, hardware (guards, etc.) and handles.
I am not a fan of buffed blades beyond a quick pass on each side of the edge after sharpening to polish off the burr. I will leave the buffing of blades to a mirror polish for others to discuss, as it is the most dangerous use of the buffer.
Most hardware is small enough and non-sharp, so buffing is a good way to get it smooth and shiny. Remember that buffing is a polishing procedure and will not take the place of proper sanding.
Handles are where a buffer is a valuable tool. It will take a nice looking sanded handle and make it shine. It will polish ivory, and stag to a lovely glow. The trick is not over-buffing and avoiding any heat build-up. This is where speed will come into play.
SAFETY:
There have been many threads about buffer safety, but the biggest rules are
1) Buff in a clear space free of clutter and obstacles.
2) Buff with your elbows in and feet apart.
3) Wear protective clothing - long sleeves and a leather apron at a minimum. Wear a face shield or other face/eye protection. Wear dust/breathing protection.
4) Pay attention to the buffing task and do not have distractions around you.
5) Do not have pets and children in the shop when buffing.
6) Do not buff when tired,or when you have been drinking.
Here are some comments I made in replys recently:
A buffer is not necessary, but is very useful. Unfortunately, most people use one that is too fast, and is set up improperly. The best setup for amateurs is a 1/2HP 3Ph motor and VFD running a buffing arbor and turning 6" wheels. The arbor should be on a raised stand and not directly on the workbench surface. There should be at least 12" of clear space past the buffing wheels in all directions. A free standing pedestal is the very best setup.
The big 1HP buffers with 12" wheels are not for novices. They should only be used mounted on a rock solid pedestal.
Hand sanding will replace a buffer. The use of the 3M polishing papers can achieve a very smooth and fairly shiny surface. They go from 400 grit to 8000 grit. However, they won't get the glossy look a buffer will on some materials. Since that glossy look isn't permanent on a user, the slightly less shiny hand buffed finish is quite acceptable.
The biggest problem with people using buffers .. especially on blades and fittings … is not sanding sufficiently before buffing. The surface should be a perfect 800 grit or better before buffing. For a mirror polish blade, the blade should be scratchless at 2000 grit before buffing.
The alternative is a smaller and lower powered buffer. A 1750 or slower RPM 1/4HP motor with dual shafts and a pair if tapered spindle shaft adapters (L & R) used with 5" or 6" wheel is very tame. You can stop it with your hand if needed. I have one made from a 1/6HP 1050RPM motor that works great on handles.
The small hobby size jewelry buffers are good for handles and fittings:
https://www.ebay.com/itm/Jewelry-Po...=16349376628452bf3e821745472285ac50fc50d38e5d
The combo units are also good, and can do a few other tasks:
https://www.ebay.com/itm/110V-Upgra...899497?hash=item260da86ee9:g:rAkAAOSwgPBb0Vap
Of course, you can get a 3 phase grinder and add a VFD - This is a good option for the non-DYI flks or those with a big shop.
https://trugrit.com/product/3-4hp-1800-rpm-3ph-buffer-3-4-shaft-334b-54-lbs/
Here is my advice on designing and building a knifemaking buffer from scratch:
1) Buy a 3 phase 1750RPM motor around 1/2HP It could be as low as 1/4Hp for a small shop or as big as 3/4HP for someone doing more buffing and using larger wheels. TEFC is great, but even an open frame buffer will work fine if you vacuum and blow it out every now and then. While a 3500RPM motor will work, the chance of running it too fast is always present.
Power should be 120 or 240VAC. Get a cheap VFD to run it. This is a task where the normal Chinese VFDs work well. Depending on your google-fu and scrounging skills, this can run from free to $100.
2) Buy/make a buffer head. They are an arbor with a pulley in the middle. You want one in 3/4" diameter with a long shaft that puts the ends at least 6" away from the housing/bearings. The pulley is in the center. Some have a 3 groove pulley for speed change, but that isn't needed when using a VFD. A hardened and precision shaft is a must. These run between $50 and $150. Klingspor carried a wonderful one for $109, but I don't see it on their website right now (call or email them). Shop Fox makes the same arbor for $140:
https://www.grizzly.com/products/Shop-Fox-Buffing-Assembly/W1681
3) You need a pedestal for a grinder. It can be a stack of 2X8s to raise the grinder up off a low bench at least 12", but a dedicated free standing pedestal is best. You can build something from 2X4s using screws and glue and screw/bolt it to the wall, weld one up with a truck rim as the base, or buy one. The $50 pedestals at HF are sort of flimsy, but will work on a small buffer.
4) Room - You need clear room behind and below a buffer. At least 24" behind and 12" below are the minimum. More is far safer. A buffer on the shop floor takes up a 36X48" space
Buffing Speed:
I am one who prefers a slower buffer to a faster one. Most buffing I do is at 1750 RPM or less, often around 750 RPM. On some woods and ivories, I buff at 300 RPM.
Buffs:
There are many types of buffing wheels (buffs for short), and they all have their uses. I would suggest a new person start with a 50-60 ply 5" or 6" coton buff. If you are really cautious, start with a 4" buff.
Buffing Compounds:
There are hundreds of types of buffing compound. For handles, use matchless white or matchless pink. These eave the least compound on the handle. Watch buffing around bolsters and pins, as the metal will make a dark streak and darken the buff.
Clean up buffing compound on handles and blades with denatured alcohol and a clean soft cloth or paper towel.
Metal can be buffer with red rouge or green chrome. Avoid getting these on handles as the may stain the wood/ivory.
TIP - Tape off the metal when buffing handles and tape off the wood when buffing metal. Those sheets of decorative colored dot stickers can be put over pins to prevent streaks on light color wood.
Basic Cleanliness:
Clean the buff with either a buff rake or a buffing against large bastard file.
Use only one compound type on a buff if possible. It is OK to use white and pink on the same wheel, but don't use chrome and white on the same wheel. Store buffs in labeled zip-lock bags.
Vacuum up around the buffer. If putting a vacuum port to catch dust, it should be directly below the wheel and at least 6" away from the wheel.
If using an open frame motor, vacuum it and blow it out every week or so.
I am sure many others will have different methods and opinions, but this will get the conversation started.
There are many pros and cons to buffers. The biggest Pro is they will bring a properly sanded surface to a shine quickly. The biggest con is they can tear a knife out of your hand and throw it quickly. These topics have been discussed at length and i suggest using the search engine to look at the past opinions on the subject.
With all the "most dangerous tool" and other talk, the fact is that most knife and machine shops that do any amount of work have a powerful buffer. The thing that makes it a dangerous tool is 50% setting it up right and 50% using it wrong.
Buffing in a Knife Shop:
There are three main things knifemakers buff - blades, hardware (guards, etc.) and handles.
I am not a fan of buffed blades beyond a quick pass on each side of the edge after sharpening to polish off the burr. I will leave the buffing of blades to a mirror polish for others to discuss, as it is the most dangerous use of the buffer.
Most hardware is small enough and non-sharp, so buffing is a good way to get it smooth and shiny. Remember that buffing is a polishing procedure and will not take the place of proper sanding.
Handles are where a buffer is a valuable tool. It will take a nice looking sanded handle and make it shine. It will polish ivory, and stag to a lovely glow. The trick is not over-buffing and avoiding any heat build-up. This is where speed will come into play.
SAFETY:
There have been many threads about buffer safety, but the biggest rules are
1) Buff in a clear space free of clutter and obstacles.
2) Buff with your elbows in and feet apart.
3) Wear protective clothing - long sleeves and a leather apron at a minimum. Wear a face shield or other face/eye protection. Wear dust/breathing protection.
4) Pay attention to the buffing task and do not have distractions around you.
5) Do not have pets and children in the shop when buffing.
6) Do not buff when tired,or when you have been drinking.
Here are some comments I made in replys recently:
A buffer is not necessary, but is very useful. Unfortunately, most people use one that is too fast, and is set up improperly. The best setup for amateurs is a 1/2HP 3Ph motor and VFD running a buffing arbor and turning 6" wheels. The arbor should be on a raised stand and not directly on the workbench surface. There should be at least 12" of clear space past the buffing wheels in all directions. A free standing pedestal is the very best setup.
The big 1HP buffers with 12" wheels are not for novices. They should only be used mounted on a rock solid pedestal.
Hand sanding will replace a buffer. The use of the 3M polishing papers can achieve a very smooth and fairly shiny surface. They go from 400 grit to 8000 grit. However, they won't get the glossy look a buffer will on some materials. Since that glossy look isn't permanent on a user, the slightly less shiny hand buffed finish is quite acceptable.
The biggest problem with people using buffers .. especially on blades and fittings … is not sanding sufficiently before buffing. The surface should be a perfect 800 grit or better before buffing. For a mirror polish blade, the blade should be scratchless at 2000 grit before buffing.
The alternative is a smaller and lower powered buffer. A 1750 or slower RPM 1/4HP motor with dual shafts and a pair if tapered spindle shaft adapters (L & R) used with 5" or 6" wheel is very tame. You can stop it with your hand if needed. I have one made from a 1/6HP 1050RPM motor that works great on handles.
The small hobby size jewelry buffers are good for handles and fittings:
https://www.ebay.com/itm/Jewelry-Po...=16349376628452bf3e821745472285ac50fc50d38e5d
The combo units are also good, and can do a few other tasks:
https://www.ebay.com/itm/110V-Upgra...899497?hash=item260da86ee9:g:rAkAAOSwgPBb0Vap
Of course, you can get a 3 phase grinder and add a VFD - This is a good option for the non-DYI flks or those with a big shop.
https://trugrit.com/product/3-4hp-1800-rpm-3ph-buffer-3-4-shaft-334b-54-lbs/
Here is my advice on designing and building a knifemaking buffer from scratch:
1) Buy a 3 phase 1750RPM motor around 1/2HP It could be as low as 1/4Hp for a small shop or as big as 3/4HP for someone doing more buffing and using larger wheels. TEFC is great, but even an open frame buffer will work fine if you vacuum and blow it out every now and then. While a 3500RPM motor will work, the chance of running it too fast is always present.
Power should be 120 or 240VAC. Get a cheap VFD to run it. This is a task where the normal Chinese VFDs work well. Depending on your google-fu and scrounging skills, this can run from free to $100.
2) Buy/make a buffer head. They are an arbor with a pulley in the middle. You want one in 3/4" diameter with a long shaft that puts the ends at least 6" away from the housing/bearings. The pulley is in the center. Some have a 3 groove pulley for speed change, but that isn't needed when using a VFD. A hardened and precision shaft is a must. These run between $50 and $150. Klingspor carried a wonderful one for $109, but I don't see it on their website right now (call or email them). Shop Fox makes the same arbor for $140:
https://www.grizzly.com/products/Shop-Fox-Buffing-Assembly/W1681
3) You need a pedestal for a grinder. It can be a stack of 2X8s to raise the grinder up off a low bench at least 12", but a dedicated free standing pedestal is best. You can build something from 2X4s using screws and glue and screw/bolt it to the wall, weld one up with a truck rim as the base, or buy one. The $50 pedestals at HF are sort of flimsy, but will work on a small buffer.
4) Room - You need clear room behind and below a buffer. At least 24" behind and 12" below are the minimum. More is far safer. A buffer on the shop floor takes up a 36X48" space
Buffing Speed:
I am one who prefers a slower buffer to a faster one. Most buffing I do is at 1750 RPM or less, often around 750 RPM. On some woods and ivories, I buff at 300 RPM.
Buffs:
There are many types of buffing wheels (buffs for short), and they all have their uses. I would suggest a new person start with a 50-60 ply 5" or 6" coton buff. If you are really cautious, start with a 4" buff.
Buffing Compounds:
There are hundreds of types of buffing compound. For handles, use matchless white or matchless pink. These eave the least compound on the handle. Watch buffing around bolsters and pins, as the metal will make a dark streak and darken the buff.
Clean up buffing compound on handles and blades with denatured alcohol and a clean soft cloth or paper towel.
Metal can be buffer with red rouge or green chrome. Avoid getting these on handles as the may stain the wood/ivory.
TIP - Tape off the metal when buffing handles and tape off the wood when buffing metal. Those sheets of decorative colored dot stickers can be put over pins to prevent streaks on light color wood.
Basic Cleanliness:
Clean the buff with either a buff rake or a buffing against large bastard file.
Use only one compound type on a buff if possible. It is OK to use white and pink on the same wheel, but don't use chrome and white on the same wheel. Store buffs in labeled zip-lock bags.
Vacuum up around the buffer. If putting a vacuum port to catch dust, it should be directly below the wheel and at least 6" away from the wheel.
If using an open frame motor, vacuum it and blow it out every week or so.
I am sure many others will have different methods and opinions, but this will get the conversation started.
