Need Advise, Flattening a Plane Iron or Chisel Back

[Stew Denton]

Hi All, I have been working on flattening the backs of plane irons and chisels, and have been using DMT diamond stones, and also sandpaper on a flat surface.

David mentioned self stick Mirka gold sanding rolls for flattening plane souls, and I have found it on Ebay, but it is a little pricy. Still, usually you get what you pay for. I have a large granite dead flat plate, but am thinking about a smaller one that I could use inside on my desk.

Because of our recent car wreck and rehab from the injuries, I wear out fairly quickly standing up working in the garage, even if only doing relatively light work, and the garage is not heated so being inside appeals. With the smaller block I can set at a chair at the desk which will be easier on me. I do have to be careful though, because I have a 20 lbs weight restriction for the time being, and am being careful to not go beyond that 20 lbs.

The question is, how do you get the sandpaper off when it is shot? I have read that it can be soaked with paint thinner or mineral spirits, and the mineral spirit will soak thru the paper, and the adhesive will give up after a bit.

Secondly does the Mirka Gold stand up to water, so that you can use water on it like you can wet or dry sandpaper for a lubricant?

Any other advise on using it or flattening a plane iron or chisel back relatively quickly will be appreciated. To this point it has been a very time consuming pain to get each one done. At least they only have to be done one time each.

Finally is any other sandpaper also good, that costs less than the Mirka? (If the Mirka is actually cheapest in the long run, I will go with it.)

Thanks and regards,

Stew

[Chuck Hart]

Get yourself a can of spray adhesive spray the block and attach the paper. It comes off easily and you don't have to use the expensive brands. The PSA adhesive on many of the self sticking sandpaper is tough to get off but if you heat it up with a hair dryer or even an old iron it comes off quickly. This way you buy whatever paper you like.

[Kees Heiden]

The problem I always have with sandpaper is dubbing of the edges. When I step from the sandpaper to the flat stones, it looks like I have to start over again. Another problem I have with sandpaper is that it dulls very quickly.

Lately I have started to use loose silicon grit on an old floortile. I use 80 grit. First this works very fast. Second, when the grit breaks down too much it is easilly replenished. If I don't replenish, the grit breaks down in smaller parts, giving a smoother result towards the end of this cycle. And last but not least I seem to get a lot less dubbing. It is a messy proces, so better done outside. Anyone know if this stuff is bad for the vegetation in the garden?

Probably this will wear my floor tile concave after a while, but I have plenty more.

[Joe Tilson]

Just had a thought: We are trying to get away from using sand paper on wood, but we need it to sharpen the tools we are using to keep from using it. Help!!

[ian maybury]

On spray adhesive. Do you mean the low strength varieties like Spray Mount Chuck?

+1 that heat is usually a good bet to shift pressure sensitive adhesives (stickers too) - get them good and warm and it will often peel off in one go. Works well on my disc sander anyway where the aluminium holds the heat nicely. Presuming it's not going to crack up due to the heat or anything a surface like your granite or glass sounds like a good idea in the event of residue being left - it should make scraping any residue off with a blade very straightforward. Probably not so easily heated though...

[Dave Parkis]

If you use spray adhesive, make sure you follow the instructions about letting it get good and tacky before pressing it in place. If you put the sand paper down while the glue is still "wet", it ain't coming off too easy at all. That's a mistake I only made once

[Judson Green]

Stew, the glue sticks available at craft stores might be an alternative to the spray glues mentioned if you're hoping to do this inside and not have to much of a mess. And I'd imagine a little heat would release it.

I've used a technique I learned of from Derek's site, but not for the bevel I only use it for flatting the backs. Clamping the paper, down stretching it as you clamp it.

Also keep a magnet near. If you sweep your work area with a magnet wrapped in a paper towel or newspaper cleaning up the fines will be easy peasy.

[Warren Mickley]

Just had a thought: We are trying to get away from using sand paper on wood, but we need it to sharpen the tools we are using to keep from using it. Help!!

Believe it or not, we worked wood long before there were Mirka Gold and spray adhesives. Granite surface plates are not found in historic woodworking inventories; bench stones are fully capable of doing this work. It took less time in the 18th century because most guys were not constantly getting new sets of chisels and new plane irons.

[Sean Hughto]

Warren, I wonder if you have an insights as to something I've always wondered about. I mostly use vintage chisels, and have examined plenty more at flea markets and so forth. I've almost never come across one that looked like the prior owner had done much of anything to flatten the back. Now I suppose 99% of the chisels out there were not owned by sophisticated users in cabinet shops, but certainly most everyone back then had a lot more everyday skill and knowledge about sharpening stuff. Any thoughts as to why back flattening (of chisels - and plane blades for that matter) doesn't appear to have been sop in the 1850 to 1930 era?

[Bill White]

Just an opinion.
Most shops were staffed by folks who worked and were paid by the volume of work that they produced. These shops were building in volume and created quality products for general public consumption.
The workers "cared" for tools with methods that would allow them to bang out quantity and so did not adhere to the somewhat obsessive attraction of the "perfect edge" that some of today's woodworkers desire.
In my shop, sharp is as sharp does. Yes I have wet stones, a Makita water sharpener, strops and honing compound, but I don't spend hours on each cutting tool achieving surgical edges.
Not being snarky. Just working wood.
Bill

[Warren Mickley]

Sean, you just can't imagine the low quality of work that was done 40 and 50 years ago. Even the old men who thought they were preserving traditional work were at a low level. I remember seeing an old man about 1976 working at a historic site and there was a trying plane on his bench. I asked him if he knew how to use the plane, "I've used it all my life". "What do you do to adjust the iron in and out?" "You can't adjust it, you have to take out the wedge and start over". In many cases there was a disdain for fineness and skill.

You can still see this kind of craftsmanship on videos. A guy will sharpen a chisel on a grey wheel, then hold the back against the side of the wheel. Then it is "razor sharp". Or sharpen the chisel on a combination SiC stone, sharpening the back on the medium side. Just really sloppy> Even tool collectors and dealers often sharpen tools this way. And because carpenters continued to use hand methods long past the furniture makers, most chisels you find were used by carpenter, handyman, home owner. This is especially true of socket chisels.

So probably some chisels you have seen were flattened on the back, just not to the fineness a craftsman would expect today.

[Jim Koepke]

The workers "cared" for tools with methods that would allow them to bang out quantity and so did not adhere to the somewhat obsessive attraction of the "perfect edge" that some of today's woodworkers desire.

Maybe it actually was the worker and not the tool that was depended upon to do fine work.

Today people expect the tool to do the work and if it fails there must be something wrong with the back of the blade, the angle of the bevel or the tool steel itself.

To the OP's inquiry of how to do this with his current restrictions, my PSA paper likely takes more than 20 lbs of pulling to remove it from my hunk of granite.

Using a spray adhesive might make for less work at the time of removal. A putty knife is also helpful.

This is a rather messy prospect for inside the house kind of work. The only thing that gets sharpened inside the house here are the kitchen knives. Then it is only some touch up on a fine diamond stone. Not sure if a coarse diamond stone is any good for flattening the backs of blades.

jtk

[Pat Barry]

You can still see this kind of craftsmanship on videos. A guy will sharpen a chisel on a grey wheel, then hold the back against the side of the wheel. Then it is "razor sharp". Or sharpen the chisel on a combination SiC stone, sharpening the back on the medium side. Just really sloppy> Even tool collectors and dealers often sharpen tools this way.

So probably some chisels you have seen were flattened on the back, just not to the fineness a craftsman would expect today.

In today's world though, its like we expect to be able to shave using the back of our chisels as a mirror. In reality we probably only need the 1st half inch of the backside to be flat and the need for polish is very questionable.

[Steve Friedman]

The problem I always have with sandpaper is dubbing of the edges. When I step from the sandpaper to the flat stones, it looks like I have to start over again.

I eliminated the dubbing problem on sandpaper with two things. First, I use the 3M Gold PSA sheets, which use A-weight paper. The combination of very thin paper and thin PSA adhesive produces very little "give" to dub the edge. The other thing is that I use the technique that Deneb Puchalski illustrates in one of the Lie-Nielsen YouTube video. You abrade the blade across the sandpaper, making sure the edge goes slightly beyond the edge of the paper. No dubbing.

Doesn't solve the cost factor, but 80 grit sandpaper is the quickest thing I have found for flattening backs.

I find that the adhesive on the 3M Gold paper comes off the granite easily with no residue. If you're not using PSA paper, try the stuff from the craft store that's meant to be repositionable - like the adhesive on the back of Post It notes.

Also, when flattening back with sandpaper, I use it dry. Neater than using it wet. Just keep a brush nearby to clear the mess off the paper periodically.

Steve

[Bob Woodburn]

[QUOTE=Any other advise on ... flattening a plane iron or chisel back relatively quickly will be appreciated. To this point it has been a very time consuming pain to get each one done. At least they only have to be done one time each.[/QUOTE]

Stew, I mean no disrespect. Rather I imagine you are beginning your personal search for the grail of the near perfect edge.

I suggest you read the link below. Actually, I mean, read and study each sentence a few times as you think about the full argument that is offered in this link. It is an elegant argument about the folly of thinking that flattening the back is useful and especially that doing it "one time" gets you anywhere.


http://www3.telus.net/BrentBeach/Sharpen/wireedge.html