Setup for Sharpening with Sandpaper of Film

[Tim Andrews]

Hello All,
I’ve come up with a slight tweak of the sandpaper method for sharpening that might be of use to someone else. I’ve been using double-stick 3M films from Lee Valley attached to a 12” square marble tile with good results, with one frustrating problem. The adhesive works so well that it takes forever, and a lot of elbow grease, to scrape off the old sheets when it’s time to replace them.

The first attempt was to simply tape the sections of film in place, not using the double stick surface, with duct tape. This was OK. The biggest problem was the thickness of the tape didn’t allow my chisels or plane blades to lie completely flat when flattening the back of the blade. Also, the tape sometimes didn’t hold well.

The solution that worked for me was to buy some 4” x 12” glass tiles from HD that are completely flat. A pack of 6 cost $14. I cut the 8 1/2×11 sheets of film into thirds, which fit perfectly on the tiles. I tried using Gorilla Tape, which seems to work slightly better than duct tape. Plus, with the 4” wide tiles, it can wrap it around the bottom for a more secure connection. The heaviest film curls slightly on the edges, but flattens out when using it. The tiles have some sort of backing which works well to keep them in place when sharpening. The tiles store easily, and you can pull out just the finest grit or 2 for touch ups while you work.

Hope this proves useful for someone else.
Cheers,
Tim

[Phil Mueller]

Tim, I’ve been considering the 3M files on glass as well. Just curious, did you try like goo-b-gone or other solvents to remove the paper?

[Andrew Pitonyak]

I thought that most people glued this stuff down. I am unsure how they removed it when it was time to put in another one; which is why I am posting here... to find out.

[mike stenson]

I thought that most people glued this stuff down. I am unsure how they removed it when it was time to put in another one; which is why I am posting here... to find out.

I use 3m 45 (the lowest tack I can find, and the same stuff I use for gluing templates to wood) to glue paper to glass for lapping, it'd work the same for sharpening. I totally ignore the instructions and just spray the sheet, and then apply while still wet. Cleanup is generally only some all purpose cleaner and a rag, I'll clean it with glass cleaner before applying.

[Tim Andrews]

Andrew, the 3M films are self adhesive. Some people use sandpaper that needs to be glued.

Phil, the hard part for me is getting the film off, before any type of solvent can be used since they don’t penetrate the film. I have to use a putty knife and lots of effort. Once the film is off, the residue isn’t a problem.

I’m engaged in a conversation elsewhere, and one gentleman replied that his sheets peel off easily, which surprised me. The only logical explanation would seem to be the surface to which the film is adhered. I’m waiting for responses, but I suspect that he is using plate glass, while I was using a glossy, smooth marble tile. The glass might be a slicker surface. I’ll post an update when I find out more.

[mike stenson]

Andrew, the 3M films are self adhesive. Some people use sandpaper that needs to be glued.

Phil, the hard part for me is getting the film off, before any type of solvent can be used since they don’t penetrate the film. I have to use a putty knife and lots of effort. Once the film is off, the residue isn’t a problem.

I’m engaged in a conversation elsewhere, and one gentleman replied that his sheets peel off easily, which surprised me. The only logical explanation would seem to be the surface to which the film is adhered. I’m waiting for responses, but I suspect that he is using plate glass, while I was using a glossy, smooth marble tile. The glass might be a slicker surface. I’ll post an update when I find out more.

Glass is, indeed, a smoother surface and would clean easier IME than a polished stone

[David Carroll]

I've moved onto diamond plates, but I used to use granite tiles and various types of self adhesive abrasives. I used a wide painter's window scraper that has a long handle and a 3-inch wide blade (replaceable). It took some effort, but it was quick work to remove the paper/film when worn.

DC

[Andrew Pitonyak]

Wow, that was a lot of good information fast.

I've been thinking about getting some of the super fine abrasives, but I'm not sure I really need them just a question of want

[Tom M King]

The 9x12 Granite Surface Plates, that Woodcraft sells on sale several times a year, hold sandpaper in place just fine with only water splashed on the surface. No glue needed. The plate is kind of heavy if you need to move it around though. I have a couple sitting on my sharpening sink drainboard, so no worries about moving. Using wet-or-dry paper, the wet used sheets just get pulled up, rinsed off, and left out to dry. The 9x12 is plenty large enough to use a whole sheet at the time.

[Mark Daily]

I use 3M repositionable spray adhesive. After using up a sheet of sandpaper, just peel it off and put a new one down. No need to remove the adhesive.

I can use any kind of sandpaper which is cheaper than PSA paper.

[Rob Luter]

I use the PSA version of the 3M film on glass that's been mounted on MDF. The blocks are sized to take 1/3 of a sheet. Heat them up a bit with a hair dryer and they come right off. A little Goo Gone and a paper towel cleans up the glass just fine.

425119

[George Yetka]

I started on the films on a piece of tempered glass.They cleaned off very easily. But I didnt have great results so I switched to diamond(didnt love that either. enjoying wetstones)

I used a razor blade only for cleaning off the surface of the glass. a fresh square razor blade took film and glue. I was using the films from lee valley as well.

[Tim Andrews]

Thanks for all the great responses, this site is a wealth of information from members who are willing to share. When I'm back home today, I'm going to try adhering a piece of film to one of the glass tiles that I bought from HD, and see if that peels off easier.

Rob, nice idea on the hair dryer. You don't think my wife will mind if a bunch of sawdust blows out when she starts using it, do you? :D

[Jim Koepke]

I can use any kind of sandpaper which is cheaper than PSA paper.

How fine of a grit can one purchase in standard sandpaper? A local automotive supply store carried as high as 2000 on my last visit a couple of years ago. My copy of The Grand Logarithmic Grit Chart puts that at about 7µ for ANSI bonded abrasive sheets. The 3M sheets have grit particles as low as 0.1µ. The seven micron size grit particles can produce a very usable edge.

For rougher work a granite slab with abrasive PSA from rolls works well. It is a bit difficult to remove at times. As Rob suggests, a heat gun or hair dryer is helpful. A wide putty knife also helps. Depending on the adhesive paint thinner may also be of help. Try different solvents sparingly to find which works best for your PSA.

One last thought. If the spray adhesives work well, could they be sprayed on the PSA backing? How about a sheet of mylar or even card stock? The PSA sheets could then be set down on a surface that can be replaced easily.

jtk

[Andrew Pitonyak]

How fine of a grit can one purchase in standard sandpaper? A local automotive supply store carried as high as 2000 on my last visit a couple of years ago. My copy of The Grand Logarithmic Grit Chart puts that at about 7µ for ANSI bonded abrasive sheets. The 3M sheets have grit particles as low as 0.1µ. The seven micron size grit particles can produce a very usable edge.

I have purchased higher, but do not remember off hand how high without checking my stock of paper. I see 3000, 5000, and 7000 readily available for wet / dry automotive use. Amazon sells 5000 grit from 3M. No idea what that is in Microns.

[Kyle Iwamoto]

I used water like Tom. You guys who glue them down, must have plates for all the grits?
I've since invested in stones, since IMO sandpaper is pretty costly, because they don't last too long, and repeatedly replacing the sheets adds up slowly. A good stone set while pricey, on the other hand, should last a long long time.

[Tim Andrews]

Kyle, thanks for chiming in. I was using water stones but got tired of having to flatten them, so that's when I decided to try this method. You're right, the expense of replacing sandpaper/film adds up. I'm thinking about getting a 2 sided diamond stone, and just using the finer films for honing. I just got a leather strop and honing compound, and that will be my last step no matter which method I end up using down the road, it's awesome.

[Tom M King]

I don't use sandpaper for sharpening irons, or chisels, but it comes in handy for other things, like jointer knives, and odd stuff that won't fit on the stones, but you still want flat.

[Phil Mueller]

My problem is my diamond plates aren’t even close to flat. Not sure if that was the way they came (didn’t check at the time), or it’s occurred from wear. I’m at a point to either replace and/or try something else. The 3M films on glass seems like a nice way to go because they don’t require the soaking or flattening (I really don’t like the mess that comes with wet stones and I don’t have a sink or source of water in the shop).

[Jim Koepke]

I don’t have a sink or source of water in the shop

My source of water in the shop is a milk jug and a spray bottle. For soaking a small plastic storage container.

jtk

[Tim Andrews]

Woo-Hoo, I think my problem is solved! It looks like the reason that the film was sticking so badly was entirely based on the marble tile I was using. Even though it looks and feels completely smooth, with a glossy finish, apparently it is nowhere near as slick as glass. I’ve attached a piece of the self adhesive film to one of the glass tiles from HD, and it adheres nicely but I can still easily lift up a corner and start to peel it off. I could never do that with the marble, it would take lots of scraping with a putty knife. I still like the idea of having each grit on its’ own 4x12 tile, so for now I’m sticking with them.

Phil, I’m no expert, but I’ve read that many of the earlier and/or less expensive diamond stones have flatness issues. This may not apply to you, but it seems that if you go that route you need to buy a high quality stone, and those will stay flat. I’m sure others here can offer some more insight.

[Tom M King]

I had a diamond stone that worked for a while. Now it's under about 45 feet of water, joining other stuff that proved to be only good enough to see how far you can throw it.

[Günter VögelBerg]

They cost a but more, but for me a granite machinist plate was a good investment and serves a multitude of uses.

[Tom M King]

The 9x12 from Woodcraft used to be on sale several times a year for $26 or 7. I'm not sure what they go for now. I bought a couple of them. One is flat to .001MM, and that a smooth hump in the middle.

[Phil Mueller]

Tom, good one. If I was near a lake that is probably where mine would be as well.

[David Bassett]

The 9x12 from Woodcraft used to be on sale several times a year for $26 or 7. I'm not sure what they go for now. I bought a couple of them. One is flat to .001MM, and that a smooth hump in the middle.

2" x 9" x 12" surface plate is in the February Sale Flyer for $30.

[Mark Daily]

According to this test done by Wood Magazine, sandpaper wears out very fast, 5-7 minutes of sharpening. Interesting..

https://www.woodmagazine.com/file/8769/download?token=ka5vzPeb

[Rob Luter]

According to this test done by Wood Magazine, sandpaper wears out very fast, 5-7 minutes of sharpening. Interesting..

https://www.woodmagazine.com/file/8769/download?token=ka5vzPeb

The 3M Abrasive film I use lasts for many months. I got the multi pack last time and that was 3-4 years ago.

[mike stenson]

The abrasive material used would change how long things last. A lot, actually.

[Andrew Pitonyak]

The abrasive material used would change how long things last. A lot, actually.

Last night, I was ripping through 3M and Norton sandpaper for flattening the back of two plane blades. I was able to very quickly use up the sand paper, but it was not diamond film. One of the blades took significant work to flatten the back and I stopped when I was about 1/4" inch of flat and shiny from the tip of the blade for part of it. There a hollow in the back center it seemed. Some brand new planes that have been sitting there waiting to be setup for user. The #7 plane took significant work to flatten the back of the blade.

https://sawmillcreek.org/showthread.php?234851-Identifying-hand-plane-made-in-India

4.5 years later, I am working on the #6 and the #5. When finished, the #7 worked great. Will now see how well the #6 and #5 work when I am done.

Flattening the back always seems to rip through my sandpaper, though. I have not actual sharpening with it in a while so I cannot comment on that. I expect flattening to be more brutal on the sand paper than sharpening.