Radiused strops

These are new products and are in limited supply for now. I only have one prototype mold with one cavity for each of the four radii, 3″, 6″, 9″, and 12″. I am looking for feedback on these to know if there are any changes I should make or if there is enough interest to make production tooling. They are all the same thickness as the Matrix stones, .25″, and consistent enough that you don’t need to compensate if swapping strops or even different radius strops. The radius strops can be used to sharpen or even reprofile knives with coarse emulsions, but take at least 3 times longer to do so compared to using Matrix stones. I know sharpening with strops is off the beaten path, but for recurve knives they do have some significant advantages over stones. The biggest is that they hold their shape for a long time as this resin is very low wear, I can’t see any wear on the two strops I have used with coarse abrasives. Next is they are all identical enough in thickness that you don’t have to compensate when switching strops, even if they are a different radius. They are easy to clean and quite resistant to contamination. I have been using one strop for 80 to 5 micron emulsions, cleaning well between grits, and a second strop for under 5 micron emulsions with good results. When I reprofiled a knife with 80-micron diamonds quite a few crystals were embedded in the resin, but many did come out when going through the grit progression, so they kind of self-clean, and didn’t cause any problems until I got down to 5 and especially 1 micron emulsions.

This resin will darken quickly if exposed to direct sunlight and does not like to be stored with mineral oil on it so clean them well before storing. I have been using 91% isopropyl alcohol to clean with and have seen no ill effects. Soap and water would work well too.

I don’t advise using tapes with the strops since I worry about them sticking too well and possibly delaminating the resin when pulling the tape off. This is unlikely, but I have better and less expensive resins to use, and will be making some soon. A nice middle ground between stones and strops.

Below are the strops I have been using to show how little they wear. The strop on the left is a 12″ radius strop that has about 3000 strokes with 80 micron diamond and a few more thousand strokes with other grits, the 80 micron diamond is certainly the hardest on them. The slanted line in the middle is following the tool marks in the mold and the closest to wear on this strop. The shiny areas mean no wear. The middle strop has sharpened 10 knives using 5 to 80 micron abrasives. The wear along the sides and middle is from dressing them with 240 grit aluminum oxide to clean up some repairs, same for the right strop, which I have only used sub 5-micron abrasives on. Both the middle and right strops are the worst seconds I have made so far, which is why I picked them for my own use. As you can see, both flat strops don’t show any wear in the middle, where we typically see stones wear when used on guided sharpeners. Also, none of the issues that make them seconds have caused any performance issues when sharpening knives, so rest assured, my second quality strops work just fine. This video shows reprofiling and sharpening a recurve knife to show what it looks like.