Sharpening a handplane's iron. Anyone?

S

Squashfan

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Jun 6, 2012
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I know people on here sharpen plane irons. Any tips? I got mine hair popping sharp and it does OK. Working on learning the adjustments, which is definitely part of my problem. I started with the fine side of a Norton India stone then went to the cheap Arkansas stone follow by black compound on a buffing wheel. I can't remember if I hit it on the white wheel or not. I did a little reading and a handplane expert said start with a dead flat stone and flatten the back of the iron. I omitted both these steps. But I am not sure how necessary a flat stone really is when you know how to sharpen properly.
 
Totally flat stone not that important, flattening the back of the iron is. Minimize any microrounding of the apex as you finish.
 
Woodworkers who sharpen chisels get all hung up about having a TOTALLY flat back on the chisel and really go to some rather extreme measures to try to make that happen. I seem to remember reading some procedure that was 10 or 12 steps and the first 8 were all about getting the back flat. I can understand why you'd want the back flat, but I would think it wouldn't matter beyond a certain point.

More on topic though: Why would a VERY flat back on a plane iron matter? The back of the plane blade never touches the work. It only touches the inside of the plane. Maybe the first 1/4 or 3/8" of the plane is going to touch wood. As long as that part is flat, I think your job is done. Unless I'm missing something.

On the other hand, I'm not a very skilled woodworker, nor do I use planes. I mean, I've used planes but only a few times. So what the heck do I know?!? :)

Brian.
 
Take a look at David Charlesworth's (i think that's the guy's name) "the ruler trick" as regards plane iron backs. Chisels are a totally different animal since the back is used to register against the work or a jig to cut precise joinery--for this you NEED an absolutely flat back. In a plane, the sole is the contact surface, and it should be absolutely flat. If you need information about plane setup, check out fine woodworking. I think they have a mandatory plane tune up article every 2 or 3 issues *eye roll*
 
Also, the angle is fairly critical. My bench plane is set at 30°, I have another plane that is meant to be run bevel side up and needs to be set at 26-27°, no higher.

A slight bit of convex is all you should tolerate, any more and it can seriously degrade performance in my experience.
 
The entire back doesn't need to be flat but the first 3/8" from the edge does need to be to have a properly formed edge. The bevel can be flat, convex, hollow doesn't matter as long as it's straight and even
 
I should have mentioned that this is a bevel up plane. Which means the back rest on that piece just behind the mouth. I can't think of the word. Anyway, thanks for the help!
 
drfreemlizard said:
Take a look at David Charlesworth's (i think that's the guy's name) "the ruler trick" as regards plane iron backs. Chisels are a totally different animal since the back is used to register against the work or a jig to cut precise joinery--for this you NEED an absolutely flat back. In a plane, the sole is the contact surface, and it should be absolutely flat. If you need information about plane setup, check out fine woodworking. I think they have a mandatory plane tune up article every 2 or 3 issues *eye roll*
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I'm a professional woodworker and furniture maker. Drfreemlizard is right, the Charlesworth 'trick' as I've always called it is the way to go. Additionally, the entirety of the back of the plane iron should be reasonably flat, as it is what registers against the plane's 'frog' or the plane bed. If you can, work the bevel on your stones up to at least 8000 if not higher, and then STAY AWAY from the buffing wheel, you'll just round the edge. Add a micro-bevel with a few additional passes on your finest stone by raising the angle you're holding the blade by 1-2 degrees, if you want. Not mandatory, but I like it.

I apprenticed in the UK under a crotchety old bugger who would make sure I had the chisel backs dead flat. At the time I hated it and couldn't understand why, but perfection with your tools leads to perfection with your work.
 
It's pretty redicoulus to think that keeping the "flat" side flat is not important. It is! if one used a tool like this as a career they would understand.
As mentioned, 8k grit or more.
You can get a jig from a good hatware store to use on stones. I have a homemade jig I use on a 2" belt grinder. I do intervals with wet stones that are marked as "af" absolutely flat.
 
I think a big deal is made of sharpening many tools, razors and wood working tools being at the top of that list.

I usually finish Chisels and Plane blades on a Shapton Pro 5k, I feel it takes a highly experienced wood worker to use an edge in the 8k+ range and actually notice the difference.
 
I personally take the micro-bevel to 8k on a Shapton ceramic, but that's just what I have. The primary bevel stops on the purple stone (5000?). I'm a big fan of micro-bevels on chisels because of how often I'm touching them up, just makes it a lot faster.

I have an acquaintance who takes everything to 30,000. He's insane, and I can't guess how long it takes him. However, his chisels are fiendishly sharp.
 
I have a bunch of dmt plates I use. My method is similar to Mr. Sellers

[video=youtube;vvTcReENk9g]https://www.youtube.com/watch?v=vvTcReENk9g[/video]
 
Jason B. said:
I think a big deal is made of sharpening many tools, razors and wood working tools being at the top of that list.

I usually finish Chisels and Plane blades on a Shapton Pro 5k, I feel it takes a highly experienced wood worker to use an edge in the 8k+ range and actually notice the difference.
Click to expand...

I have to agree with you here. I ain't gonna knock anyones way of sharpening but how did they sharpen planes back in the day? I have a book that belonged to my grandfather, which I had forgotten about, that was written back when they still used planes daily. They hollow grind the bevel on a wet stone grinder, follow it up with an oil stone and a lether strop. Wonder how it worked?

I would love to hollow gring my iron and chisels. It would be a much better grind for micro beveling.
 
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