Kylun,
If you are taking the material down too much, I would consider a much finer grade of sandpaper. And/or possibly reconsider your technique.
.... not trying to sound too critical or judgemental here... just making some assumptions. Bear with me.
Try at least 400 grit and maybe 600-800 grit or higher. You can usually find 600, 800, 1000, 1500 and 2000 grit sandpaper at auto stores.
Most of the big box hardware stores won't carry over 400 grit since you don't usually use them for woodworking.
I would think 600 - 800 would be sufficient. 400 grit might be fine enough, but 400 will probably still leave the G10 a little dull.
I would think the 400 could just be lightly used to knock off any pricklies and follow with 600 - 800 to buff it up a little more.
If you can't find 600 - 800 grit or higher, you might try 400 grit followed with 0000 steel wool (????). Or just try 000 wool followed by 0000 wool (????).
I am pretty confident you shouldn't need 1500 - 2000 for G10 or micarta.
1000 grit .... not likely needed, but maybe preferred (???).
1500 - 2000 grits will "start" to put a mirror finish on steel. You shouldn't need that much polish. Plus, the finer grit papers at an auto store cost more than the common grits at the big hardware store. I would probably recommend either not purchasing over 800 grit or purchase and don't open unless you feel you need to and then return if you don't use. I have some for when I want to polish certain materials. But, I think it is expensive. I don't like paying for it.
* Steel wool is cheap.
Also, when sanding detail and small contours, I find it is better (for me) if I rip small pieces about 1" - 2" and just sand with the tips of my fingers or side of my thumb. Same with steel wool. I don't use the whole pad for detail work. I just rip small pieces.
If you are sanding the whole handle all at once, especially if using 150, 220 or even 320 grit paper, you will likely be "Re-Shaping" the handle.
* Based on your description of the pricklies, I would think you would only need to focus your sanding efforts in the grooves. I would think this would be a common area for "fuzzies" or in this case "Pricklies" to happen. It is easier to sand and polish the more exposed areas. Those grooves are cut with carbide cutters on a CNC machine, then I am sure the Busse/Swamp Rat crew goes over the handles with some sort of wheel or belt sander or buffer. The raised areas probably just got cleaned up more and the grooves just got missed a little. The fix should be easy enough with the right tools and technique.
400 grit would probably fall in the middle of reshaping vs. smoothing and polishing.
I would think steel wool would actually work well with G10. For pricklies on G10, I am guessing that 000 followed with 0000 would work very well and steel wool is cheap.
3M and some other companies make buffing wheels and pads as well out of various synthetic materials with abrasives embedded in the material.
I know many people are using the Scotch-Brite buffing wheels for micarta and steel. I think they can be used with a drill. But, I am not familiar enough with the various grits on those type of wheels. You would probably have to do a search for Scotch-Brite, a little trial and error or somebody else would need to post.
I have been meaning to try the Scotch-Brite wheels. I am sure they would be great for many different uses on steel and various handle materials. I just can't advise on the different grits.
Off of the top of my head, I think the following sandpaper grits and steel wool grades are about alike:
00 steel wool pretty close to 320 - 400 grit sandpaper
000 steel wool pretty close to 400 - 600 grit sandpaper
0000 steel wool pretty close to 800 - 1000 grit sandpaper
Here is a decent link explaining 3M pads, wool and paper grits and uses:
http://academic.evergreen.edu/projects/biophysics/technotes/fabric/finish.pdf
I am guessing a little here, but I think a material that might buff micarta might actually dull G10 because of the difference in material charactieristics. You might need one grit finer for G10 compared to micarta (????).
I have two of the G10 models and I have not been able to find any issues with pricklies. All of mine are very smooth.
I would think it would be very easy to remove little pricklies from G10. So, my explanation may be overblown and probably took me at least 5 times longer to type than it would take to remove the pricklies, but I hope it helps.
Good luck.
Sorry to hear you are having issues. I love my G10.
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