What's your favorite fine grit PSA roll sandpaper (for sharpening)

[John C Cox]

Hey guys,

I am looking for suggestions for fine grit sandpapers for sharpening duty. I want PSA sandpaper that comes in rolls.. Realistically, I am not looking for $2,000/roll lapping films.

Looking for 600,800, and 1000... I would really prefer something I can buy on Amazon... And I want something that mostly releases easy without too much scraping and lacquer thinner..

[Patrick Chase]

Hey guys,

I am looking for suggestions for fine grit sandpapers for sharpening duty. I want PSA sandpaper that comes in rolls.. Realistically, I am not looking for $2,000/roll lapping films.

Looking for 600,800, and 1000... I would really prefer something I can buy on Amazon... And I want something that mostly releases easy without too much scraping and lacquer thinner..

All of the PSA sandpaper lines that I use (Mirka, 3M stickit, Klingspor) top out at 500# or so.

I think that the issue there is that when the particle size gets down that small the thickness/profile variations of the paper substrate itself become significant. That's why we only see super-fine abrasives in films, compounds, and stones.

[Bob Glenn]

I use the black silicon carbide wet/dry sand paper on a piece of float glass. I keep a spray bottle of water to spray on the glass then put the paper on. Surface tension keeps the paper in place during sharpening. Available to 2000 grit in most auto stores. BTW, I move the blade side to side, rather than back and forth on the sand paper when sharpening. With wet paper you can see when the edge is in contact with abrasive.

[steven c newman]

About the same here, except the 1K -2.5K paper gets laid right on top of the 600 Medium India stone, and the oily film on the stone keeps the paper from sliding....K.I.S.S.

ps: they also sell 3,000 grit paper right beside the pack of assorted papers I buy....

[steven c newman]

Beginning to think that SMC should start a separate forum.....just for sharpening threads....Hmmmmm?

[John C Cox]

I used to use the SiC automotive paper in the past stuck down with a bit of water. Even rinsed it off and dried it back out when it wasn't spent... Meh. I want something I can stick down.. And the 3M spray goo is often globby, but mostly just too "forever gooey"...

I did see some AlOx roll lapping film that wasn't too expensive ($40/roll or so) that runs up to about 3,000 grit... Any opinions about that stuff?

[Patrick Chase]

Clarifying my previous reply: The OP asked about "PSA roll" paper, so the answer I gave was based on that.

If we're talking about non-PSA sheets then yes, SiC is available to much higher grits. I suspect that there are two reasons why SiC papers are available to high grits while similarly graded AlOx is only available on film backings:

1. SiC is friable, so any substrate thickness variation may "self-correct" via abrasive breakdown.
2. Wet-and-dry papers are mostly used for sanding out finishes, and for that purpose they're generally used with a flexible backing of some sort which reduces the importance of uniform thickness. In contrast AlOx is more commonly used for metalworking, where rigid backings are more common and thickness variation is a big issue.

One other thing to keep in mind is that SiC breaks down pretty quickly (as noted above, it's highly friable) when used on hard steels. That can be a positive thing if you're dealing with HSS and nothing else will work, but it also means that the economics of SiC paper vs AlOx film aren't as favorable to the paper as they may appear based on cost/sheet. The film will last quite a bit longer on most steels. FWIW I'd go with the film (and I keep some on hand to give out to friends getting started with hand tools).

[Rob Luter]

I use the 3M films available at TFWW and have been really pleased. Go with the multi packs.

[Patrick Chase]

I use the 3M films available at TFWW and have been really pleased. Go with the multi packs.

Lee Valley also sells the Al-Oxide films in a wider range of grits than TFWW, though TFWW's prices are a bit better for the ones that they both sell: http://www.leevalley.com/us/wood/pag...29&cat=1,44047

For reasons I outlined in a previous post I generally prefer Al-Oxide for metal work.

[Rob Luter]

Lee Valley also sells the Al-Oxide films in a wider range of grits than TFWW, though TFWW's prices are a bit better for the ones that they both sell: http://www.leevalley.com/us/wood/pag...29&cat=1,44047

For reasons I outlined in a previous post I generally prefer Al-Oxide for metal work.

Thanks for the tip Patrick. I'll check those out.