- 3M 415N 320 Grit Sandpaper (No longer manufactured, superseded by 426U)
- 3M 426U 320 Grit Sandpaper (Single Sheets)
- 3M 405U 500 Grit Sandpaper (6 pk)
- icro-Mesh™ Ultra-Flex Regular (also Here)
Places to Buy: Various online places, including eBay, StringsByMail, and Amazon, as well as various brick and mortar outlets such as Autozone, Walmart and others.
Size/Count: Single-sheets, 20, 50, 100, Variety packs
Guarantee: No, as these are consumable products
My Rating: 10/10
- Silicon Carbide is what makes up the ‘grit’ of the sandpaper and is ideal for general purpose sanding on wood, metal, plastic, dry wall, fiberglass, glass, and ceramic. Aluminum Oxide is a good alternative sandpaper material though it is less sharp and wears faster; in industrial applications this might be a problem, but for our usage, not so much.
- Stearate coating and open coat construction minimize loading (which means the dust of whatever you’re sanding doesn’t remain ‘stuck’ between the particles, thereby clogging it)
- A-weight paper provides flexibility for finishing contours and angles making it easy to get around and under the fingernail edges. Sandpaper paper weights are given in letters, ‘A’ being the thinnest paper, ‘B-weight’ being slightly thicker, and so on.
- Paper sheet is easily sized according to the task (with a scissors). This is also true for sandpaper brands which have rubberized or padded paper backings.
- 9″ x 11″ sheets divided into quarters fit most hand-sanding blocks I’ve also seen it sold in rolls and disks but these usually have an adhesive backing to attach to sanding blocks or electric sanders; something which you might do better to stay away from.·
Pros & Cons:
- Pros: The 3M 415N 320 Grit is the silicon carbide sandpaper I’ve used for years now, and it works perfectly for polishing the edges of fingernails; all important if you use your nails for fingerstyle guitar playing.
- Cons: But…if you noticed, the stuff is near impossible to find online because 3M no longer makes it. Online places sometimes (rarely) sell the sheets in bulk packs (50-100 pcs) but as you’ll need, at most, just a couple of 9″ x 11″ sheets – since you’ll be cutting them up into 1-inch squares – it’s not cost effective to buy in bulk. You might come across unused old-stock at auto body shops or wood-working/finishing places, but pretty much, according to a 3M representative, 415N has been replaced by the 426U sandpaper.
- Price: Even the 426U sandpaper comes in bulk packs at $50-$70 per pack and so it’s still not cost effective in my opinion. Better to try eBay and the other alternatives mentioned at the top of the page.
Recommended? I still have most of one sheet left of the 3M 415N, and because I use small 1″x1″ squares, it will probably last me another 10-20 years, which at my age, is most likely the rest of my life. But if I ever do need to replenish my supply, I’d probably look for the 426U at eBay (though the shipping’s high), or the 405U from StringsByMail. The 405U is 500 Grit, but from what I’ve heard, it works great.
I also have to add that I’ve never tried grits close to 320 – the 220, the 180, for example – though I’d lean more towards the finer, higher grit number if possible; 300’s and up.
It would also worth looking into the very popular Micro-Mesh products made by Micro-Surface Finishing Products. These grit surfaces range between 1500 and 12,000 (!) and would be interesting to try out. 12,000 seems almost fine enough to rub out scratches in your guitar finish, but don’t quote me on that.
Anyhow, that’s my assessment, and though it can take a little looking around it’s well worth the trouble it might take, though your local music or autobody supply store might have some of these items just right there behind the counter.
You never know.
If you ever need a hand with something or have any questions or comments, feel free to leave them below.
Fingers On Strings
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