Polishing question

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Maddogfl
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Polishing question

Post by Maddogfl »

I have been polishing on a 1/4 hp motor salvaged from a dead drill press, using a 6" wheel directly attached to the motor shaft, using green compound. I am only getting about 2700 ft/min so it is taking some time to get results, but eventually I get moderate results. I just salvaged a 1/2 HP motor from an old treadmill, (running at 1725 rpm), and I am thinking about directly attaching a 12" wheel, bringing the speed up to around 5400 ft/min. I am trying to determine if I want to go through all of the trouble to add pulleys to gain speed or will my results at 5400 ft/min suffice?
ea42
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Re: Polishing question

Post by ea42 »

I run all my buffs at 1750 RPM, never faster. The higher the RPM's the more heat you produce, plus you'll wear away softer material to the point of gouging before you realize what happened. Not to mention how dangerous a super high speed buff is if that knife or blade happens to get away from you.

Try going to black compound rather than green if you have heavy scratches, then switch to green or white once you have them polished out.

Eric
Maddogfl
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Re: Polishing question

Post by Maddogfl »

ea42 wrote: Fri Nov 05, 2021 1:02 am I run all my buffs at 1750 RPM, never faster. The higher the RPM's the more heat you produce, plus you'll wear away softer material to the point of gouging before you realize what happened. Not to mention how dangerous a super high speed buff is if that knife or blade happens to get away from you.

Try going to black compound rather than green if you have heavy scratches, then switch to green or white once you have them polished out.

Eric
Thanks Eric. I was reading about minimums of 5500 to 7000 ft/sec. That is what made me ask the question. It is all new to me so I don't have a clue.


Most electric motors that I deal with are standard at 1725 rpm. Work that out and you come with far lower numbers than what I was reading, meaning that you would need a huge polishing wheel, or gearing (in fact pullying) up to get to 7K ft/sec. I am going to put the 8" wheel directly on the 1725 rpm motor and see what happens. I have plenty of cheap knives to experiment with. I am like you though, it sounds scary to run a cloth wheel at supersonic speeds....I got smart and glued an old leather belt on a discarded grinding wheel as an experiment. The first time I used it I discovered that the glue I used wasn't good enough, about 90% of it came undone. The damn thing beat me half to death before I could hit the off switch. ;)

Steve
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Nev52
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Re: Polishing question

Post by Nev52 »

I also have a question on polishing. After sanding the bolsters what compound do you start out with? I have tried white and green but sometimes I can't get small scratches out. Also, what do you polish the handles with?

Thanks
Nev
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btrwtr
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Re: Polishing question

Post by btrwtr »

Nev52 wrote: Thu Mar 10, 2022 1:08 pm I also have a question on polishing. After sanding the bolsters what compound do you start out with? I have tried white and green but sometimes I can't get small scratches out. Also, what do you polish the handles with?

Thanks
Nev
This would depend on what grit you are using for sanding. Using 340 or 400 grit I can usually get good results with my buffer on a loose unsewn muslin wheel with pink no scratch compound. The buffer motor speed and wheel size also make a difference. I find it necessary to alternate the angle of contact often to keep the bolsters from streaking. Sanding out to 600 grit it is much easier to get good results. The finer the grit the easier the buffing. Cross sanding between grits is a good idea. My buffer is home made using a 1750 rpm 1/2 HP motor belt driving a 10" wheel. I use this same setup for handles.
If I have seen further it is by standing on the shoulders of giants.

Wayne

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Jeffinn
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Re: Polishing question

Post by Jeffinn »

I use a 1750 rpm buffer with black magic compound for most of my bolster and handle polishing.
Like Wayne said, sanding to a finer grit will give better results. I sand my bolsters with 220 grit, 400 grit and 600 grit before polishing. I occasionally use 800 grit under certain circumstances. I have most of the different colored compounds I just seem to have the best results with black magic. Pink no scratch is good as well.
Jeff
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Nev52
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Re: Polishing question

Post by Nev52 »

btrwtr wrote: Thu Mar 10, 2022 2:38 pm
Nev52 wrote: Thu Mar 10, 2022 1:08 pm I also have a question on polishing. After sanding the bolsters what compound do you start out with? I have tried white and green but sometimes I can't get small scratches out. Also, what do you polish the handles with?

Thanks
Nev
This would depend on what grit you are using for sanding. Using 340 or 400 grit I can usually get good results with my buffer on a loose unsewn muslin wheel with pink no scratch compound. The buffer motor speed and wheel size also make a difference. I find it necessary to alternate the angle of contact often to keep the bolsters from streaking. Sanding out to 600 grit it is much easier to get good results. The finer the grit the easier the buffing. Cross sanding between grits is a good idea. My buffer is home made using a 1750 rpm 1/2 HP motor belt driving a 10" wheel. I use this same setup for handles.
What brand is the pink compound. Also, can you tell me where I can purchase it?
Thank you
Nev
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Nev52
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Re: Polishing question

Post by Nev52 »

Jeffinn wrote: Thu Mar 10, 2022 6:41 pm I use a 1750 rpm buffer with black magic compound for most of my bolster and handle polishing.
Like Wayne said, sanding to a finer grit will give better results. I sand my bolsters with 220 grit, 400 grit and 600 grit before polishing. I occasionally use 800 grit under certain circumstances. I have most of the different colored compounds I just seem to have the best results with black magic. Pink no scratch is good as well.
Jeff
Jeff,
Are you using black magic the car polish?

Nev
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Jeffinn
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Re: Polishing question

Post by Jeffinn »

No, it’s black magic polishing compound.
Jantz has it: https://knifemaking.com/collections/pol ... lack-magic
Jeff
Hey … it’s a pocketknife for gosh sakes. I’m not selling the Mona Lisa….Bullitt4001
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btrwtr
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Re: Polishing question

Post by btrwtr »

Nev52 wrote: Fri Mar 11, 2022 1:26 am
btrwtr wrote: Thu Mar 10, 2022 2:38 pm
Nev52 wrote: Thu Mar 10, 2022 1:08 pm I also have a question on polishing. After sanding the bolsters what compound do you start out with? I have tried white and green but sometimes I can't get small scratches out. Also, what do you polish the handles with?

Thanks
Nev
This would depend on what grit you are using for sanding. Using 340 or 400 grit I can usually get good results with my buffer on a loose unsewn muslin wheel with pink no scratch compound. The buffer motor speed and wheel size also make a difference. I find it necessary to alternate the angle of contact often to keep the bolsters from streaking. Sanding out to 600 grit it is much easier to get good results. The finer the grit the easier the buffing. Cross sanding between grits is a good idea. My buffer is home made using a 1750 rpm 1/2 HP motor belt driving a 10" wheel. I use this same setup for handles.
What brand is the pink compound. Also, can you tell me where I can purchase it?
Thank you
Nev
Here is a link to Texas Knifemaker's Supply that shows the pink compound. There are other places that sell it as well.

https://www.texasknife.com/vcom/index.p ... c893317539
If I have seen further it is by standing on the shoulders of giants.

Wayne

Please visit My AAPK store https://www.allaboutpocketknives.com/catalog/btrwtr
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Nev52
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Re: Polishing question

Post by Nev52 »

Thanks Men ::handshake:: I will check it out.

Nev
Folgore1

Re: Polishing question

Post by Folgore1 »

i get alot of comments and questions how do you get your knives sooooo awesome looking lol , i use a green compound first then i use a pink (no scratch) compound and have had awesome results , been using this combo for around 20+ years now.
i get the compounds from K&G they come in huge bars about a foot long and 3 inches thick , they make 2 different greens so i bought both , one of them they guarantee is the best green compound on planet earth or your money back no questions asked it is sum bomb stuff works great ::tu::
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