Nathan the Machinist
KnifeMaker / Machinist / Evil Genius
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Feb 13, 2007
- Messages
- 15,741
Ever wish you could have some of the delicious delicious stropping compound that we make here at the shop? The magic compound with multiple championship titles on it including the current national and world Bladesports cutting Championships.
I have tried about every kind of strop, buff and mold polishing compound out there and finally made my own.
Here are my thoughts on the matter.
Most stropping compound is some form of an oily paste or (worse) wax based. I have found these to have some disadvantages. Particularly when temperature control is important and you can't just turn up the speed to make up for their mediocre cutting ability due to the heat generated. If you're stropping like me, with relatively low pressure at low speeds, these don't get the job done very well and they often leave a mess on the blade that new knives can't ship with.
There was a stropping compound called Hand American, Chromium Oxide that I really liked. It went on as a goo and it dried into a non-oily friable powdery film that did a great job. Unfortunately they don't make it anymore. They do make a "heavy concentration diamond spray" and it does work and I've used a ton of it. It is $22 for two ounces and it contains 10 carats. My diamond spray is $50 for one ounce, and it contains 25 carats.
My shmoo is 50% alcohol by volume and dries quickly without any oil or sticky residue. It can be used on a new strop but it can also be used on an old strop on top of oil or wax. It comes in a spray bottle so it can be sprayed as a mist, leaving behind 98% diamond and a 2% that acts as a binder, and nothing else. There is a lot of diamond and it builds up in tiny high concentration droplets that, once dry, wear down and expose fresh diamond as you strop. This gets you a screaming sharp edge, quickly and without heat.
The main advantage to my shmoo is that it dries quickly, works quickly and leaves no residue. The main disadvantage is that it does tend to clog. Therefore, it is important to always shake your spray before using it because particles can sink to the bottom, which can clog your spray if too many go through at once.
For best results:
Shake well
The bottle ships half empty. The extra space in the bottle allows you to effectively shake and mix the compound before use.
Spray the compound on your strop, applying an even spray until your strop is about 50% white with diamond. There will be overspray. You will waste some. Such is life.
Do not spread it out or rub it in. You want the little droplets to dry in place. Let it dry for about 5 minutes before use.
Put the cap back on. It will dry and get corked up if you don't.
If your spray gets clogged you can crack the bottle open a little bit and then apply compressed air to the spray exit. This will usually dislodge whatever traffic jam of diamond particles that are clogging your spray back down into the bottle.
These ship with a spare spray bottle. You can fill the spare bottle with soapy water and spray that through your nozzle. This will often clear it.
If it stays clogged, you will need to use the spare sprayer.
I use my spray bottle several times a week and I don't get a lot of clogs. But, if you let it sit a long time without use it can start to be a problem.
Your spray should not sit months at a time without being shaken. The diamond will eventually fall out of the emulsion and it could, eventually, cake up enough that it won't go back into a mixture.
Through experimentation, we have found that a mix of grit gives us the best cutting edge. Without divulging what exactly we're doing (Bladesports is very competitive), I will say that most of the particles are very fine but some are fine. This is a key difference between sharpening a knife and polishing an optically perfect SPI A1 mirror finish mold cavity. A few fine scratches in your mirror finish make it cut better. This is good for your knives but may be too toothy for shaving. (You tell me, I don't know)
We will have this available on our website soon and they can be added to knife orders immediately or you can contact Jo to place an order.
Edit to add: to answer a question I just got. No, this is not just diamond powder and alcohol. I've tried that. And soap. And detergent. And everything else. Diamond powder clumps up and also drops out quickly. Getting this much diamond to mix properly and stay in a suspension that adheres to the strop but doesn't leave a residue build up or get sticky was a challenge that I eventually figured out.
I have tried about every kind of strop, buff and mold polishing compound out there and finally made my own.
Here are my thoughts on the matter.
Most stropping compound is some form of an oily paste or (worse) wax based. I have found these to have some disadvantages. Particularly when temperature control is important and you can't just turn up the speed to make up for their mediocre cutting ability due to the heat generated. If you're stropping like me, with relatively low pressure at low speeds, these don't get the job done very well and they often leave a mess on the blade that new knives can't ship with.
There was a stropping compound called Hand American, Chromium Oxide that I really liked. It went on as a goo and it dried into a non-oily friable powdery film that did a great job. Unfortunately they don't make it anymore. They do make a "heavy concentration diamond spray" and it does work and I've used a ton of it. It is $22 for two ounces and it contains 10 carats. My diamond spray is $50 for one ounce, and it contains 25 carats.
My shmoo is 50% alcohol by volume and dries quickly without any oil or sticky residue. It can be used on a new strop but it can also be used on an old strop on top of oil or wax. It comes in a spray bottle so it can be sprayed as a mist, leaving behind 98% diamond and a 2% that acts as a binder, and nothing else. There is a lot of diamond and it builds up in tiny high concentration droplets that, once dry, wear down and expose fresh diamond as you strop. This gets you a screaming sharp edge, quickly and without heat.
The main advantage to my shmoo is that it dries quickly, works quickly and leaves no residue. The main disadvantage is that it does tend to clog. Therefore, it is important to always shake your spray before using it because particles can sink to the bottom, which can clog your spray if too many go through at once.
For best results:
Shake well
The bottle ships half empty. The extra space in the bottle allows you to effectively shake and mix the compound before use.
Spray the compound on your strop, applying an even spray until your strop is about 50% white with diamond. There will be overspray. You will waste some. Such is life.
Do not spread it out or rub it in. You want the little droplets to dry in place. Let it dry for about 5 minutes before use.
Put the cap back on. It will dry and get corked up if you don't.
If your spray gets clogged you can crack the bottle open a little bit and then apply compressed air to the spray exit. This will usually dislodge whatever traffic jam of diamond particles that are clogging your spray back down into the bottle.
These ship with a spare spray bottle. You can fill the spare bottle with soapy water and spray that through your nozzle. This will often clear it.
If it stays clogged, you will need to use the spare sprayer.
I use my spray bottle several times a week and I don't get a lot of clogs. But, if you let it sit a long time without use it can start to be a problem.
Your spray should not sit months at a time without being shaken. The diamond will eventually fall out of the emulsion and it could, eventually, cake up enough that it won't go back into a mixture.
Through experimentation, we have found that a mix of grit gives us the best cutting edge. Without divulging what exactly we're doing (Bladesports is very competitive), I will say that most of the particles are very fine but some are fine. This is a key difference between sharpening a knife and polishing an optically perfect SPI A1 mirror finish mold cavity. A few fine scratches in your mirror finish make it cut better. This is good for your knives but may be too toothy for shaving. (You tell me, I don't know)
We will have this available on our website soon and they can be added to knife orders immediately or you can contact Jo to place an order.
Edit to add: to answer a question I just got. No, this is not just diamond powder and alcohol. I've tried that. And soap. And detergent. And everything else. Diamond powder clumps up and also drops out quickly. Getting this much diamond to mix properly and stay in a suspension that adheres to the strop but doesn't leave a residue build up or get sticky was a challenge that I eventually figured out.
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