Plane sharpening advice needed

[TRITON]

Sharpen knives with a steel.

Just a minor point there J. You don't sharpen knives on a steel, you hone them.

 

[tibi]

What's a micro back bevel ?

It is the bevel that is created by the ruler trick on the flat side of the blade.

 

[tibi]

Assuming you do the grind at 240 and 25 degrees, add a secondary bevel at 27 with the finest diamond hone - just a small one - skip the rest of the hones except for the finish hone - the others are a waste of your time.

Use a guide or something to get a feel for this, but add a tiny third bevel on the chinese stone you have there at around 32 degrees.

When you get your loupe, confirm that you see nothing but the finest scratches at the edge. Strop lightly on the strop and nothing more.

The chinese stones are notoriously slow, unless they're compressed agate, and then they can be coarser than 10k grit (I have one of each type - the natural ones are drastically different - but too slow for practical use to follow a 1200 grit diamond edge without steepening the angle a lot.)

You have only two things really to consider - is the geometry of the final bevel about right, and then, can you ensure visually that the fine scratches get all the way to the edge and is the edge damage free.

There is no mystery other than that - your loupe will help you.

Sellers pitches this method with a gaggle of plates and just honing right up the line, but few people get the fine scratches to the edge with no damage, and most steepen the edge in the process - bad practice. Your objective is to get the edge finished in as little work as possible and have it resistant to damage in use. Anything else is dumb. What paul teaches is a beginner's method, but you don't want to be a beginner for more than a very short period of time. The loop is your key in seeing what you're actually getting done (a small hand scope is also a decent idea - the ones that are about 15 pounds on ebay) and halving your sharpening time and getting a better result- both in sharpness and durability. You won't need the loupe for long - just until you get the feel of things.

You'll also probably quickly get to the point where you're grinding and finish honing at angles separated far enough that you don't need a guide for anything.

Hello David,

thank you for your advice. Yes it is an agate stone. I am waiting for my loupe, but they have send me a wrong one (3-8 x only), so I need to wait for a replacement (30-60x). I think that the loupe and good light will help me the most. I can only feel the burr on the edge with the diamond stones, but that is probably not enough, so loupe will help me see, if I do not get rid of all the burr or I do not meet the edge or some other issue.

 

[tibi]

dump the ruler trick, by the way. It's also a beginner's trap. when you work the back of a tool, put your fingers where you want the stone to work the metal but leave the tool flat on the stone. If you're coming up short when you can see the scratches on the back, you may want to first work the back on something faster, but even a 1200 grit diamond hone is coarse. A broken in fine india stone is nice for this as it requires little maintenance.

My old blades are slightly bent, they are not perfectly straight. That is why ruler trick helped me avoid a lot of flattening.

 

[Adam W.]

The ruler trick is ?

 

[D_W]

My old blades are slightly bent, they are not perfectly straight. That is why ruler trick helped me avoid a lot of flattening.

I think over time, the ruler trick will cost you time, and when I've tested plane irons, a 0.5mm ruler, or even a 1mm ruler cannot remove edge wear on a dull plane iron without being ground back far enough that it grows.

You're better off if you gradually work the backs flat and then discard the ruler trick - make yourself an iron holder to work the irons if needed, that's my suggestion. If a stone is too slow to do the back work without the ruler trick, it's probably too fine to be practical (the SP 13000 waterstone comes to mind - great to make a tiny very highly polished bevel, but it takes about 30 seconds of continuous use on the back of a tool with directed finger pressure just to remove routine wear - not even considering potential damage or deep scratches).

In terms of the agate stones, they don't really leave a burr because they're not cutting fast enough to leave one. That's something you can take advantage of, but not great if you're removing considerable scratches.

But, when you get the loupe, it will really tell you what you need to know and you can adjust from there.

Part of the reason most sharpening advice on forums fail is the same reason most people fail with the sellers method - nobody can tell what the problem is without seeing it. On a shaving forum, I read all kinds of goofiness about microchipping, and so on and so forth until goading half of the people there to buy a microscope. Razor honing is different, done less often, but has to be done deliberately. Most people with problems have created geometry where the finish stone isn't touching the edge ,and they blame something else - and then a small scope will rat them out and suddenly most of the "defective razors" and other anomalies go to the wayside. Rule number one is the edge has to be finished and damage free, #2 is geometry - everything else is far behind. with a 25 degree bevel, you'll never get damage past the last bevel, so there's no need to do lots of work in the steel above the last bevel. If you find the agate is too slow or difficult to fully finish an edge later, send me a PM with what you have available locally and i"ll make a suggestion. There are a lot of natural stones (like the cretans coming out of greece) that are about half as fine and 8 times as fast, and should be not-so-expensive in continental europe. They can be stepped up to an optical polish with simple honing compound, and they do a great job finishing the backs of tools because they're fine, but fast enough.

 

[D_W]

The ruler trick is ?

propping up a flat-backed tool to make a very shallow secondary bevel on the back so a fine abrasive will work at the tip of a tool. It's a bit of a trap, but useful for beginners to get the feel of a sharp edge.

 

[D_W]

I have separate advice for knives, but I'll leave it out of here. it's kind of the same principle, except you don't need to do much grinding on knives. Your loupe will come in handy there, too.

 

[Jacob]

Just a minor point there J. You don't sharpen knives on a steel, you hone them.

I sharpen mine.

 

[tibi]

The ruler trick is ?

Please ask @David C . He is the best to explain this topic.

 

[Adam W.]

I suspect @tibi that you're just making it far too complicated for yourself and getting your knickers in a twist.

Could you not just try a medium stone to raise a bur, polish it off with a fine stone and give it a strop, and see how you get on?

 

[Jacob]

I suspect @tibi that you're just making it far too complicated for yourself and getting your knickers in a twist.

Could you not just try a medium stone to raise a bur, polish it off with a fine stone and give it a strop, and see how you get on?

Spot on. Too many stones and too many ideas just makes it more difficult.
But to get back to the problem - to plane rough oak which has been out in the garden for years you need a scrub plane, or even an adze, to get the surface cleaned up enough to plane.

 

[Adam W.]

Indeed, but any old plane with a curved iron will do, or does one require a special n' dedicated scrub plane ?

Hmmmm, I wonder.....

 

[Ttrees]

Maybe I misunderstood you, but I was thinking that you are talking about lowering the honing angle on the green stone, not having the stones of equal height. What benefit would give me having the stones of equal height with the green stone?

I was going to ask if you were getting a burr on the diamond hones, which I see you have been.
That's a large part of the answer to this question IMO.

Don't know how good my edges would be if things were the other way round, as you can see my sharpening station is pretty high.

Tom

 

[Jacob]

Indeed, but any old plane with a curved iron will do, or does one require a special n' dedicated scrub plane ?

Hmmmm, I wonder.....

I base it on my experience with an ECE scrub which does the job really well. Small - about the size of a 3, single iron narrow blade 33mm, tight camber with radius 25mm.
Small means light weight which is good as it's an energetic process, tight radius means deep narrow cut and also means you don't need a wider blade as you'd never get the full 33mm width of cut anyway.
The idea is to remove material fast and deep so you are into the cleaner wood quickly.
It's also very easy to sharpen freehand on a medium stone and it doesn't matter if there are a few nicks as you are only doing rough planing anyway.

 

[Adam W.]

Yes, they're very good. I have a Lie-Nielsen one too, but don't tell anybody.

 

[Woody2Shoes]

Yes, they're very good. I have a Lie-Nielsen one too, but don't tell anybody.

I always feel very productive when I use my (LV) one...

 

[tibi]

Spot on. Too many stones and too many ideas just makes it more difficult.
But to get back to the problem - to plane rough oak which has been out in the garden for years you need a scrub plane, or even an adze, to get the surface cleaned up enough to plane.

I have a Pinie wooden scrub plane, similar to ECE, but less expensive. I have been using it on the oak to remove initial dirt and stones. But the problem is that once I get the board almost flat and I need to make minor adjustment, the blade just will not cut and just slides on the surface. If I increase the cut, it digs in. The surface is clear of dirt at this point. So the issue must be in the sharpness. Once I sharpen, I can make a few passes, but then it stops cutting again. I should be able to get a conitnuous shaving once the wood is flat, but I do not get any shaving, unless I use a freshly sharpened blade.

 

[Jacob]

What is your actual planing set up like? Are these big timbers On a bench? Maybe you need something in between scrub plane and jack e.g. a jack with a very cambered blade?

 

[D_W]

what you describe is either a dull blade or lack of clearance (probably the latter).

Dullness ultimately will create a lack of clearance (and when I get blades from people who use the "sellers method", they always either have lack of polish at the tip, or lack of clearance, or both).

As you mention that you have a 1k/4k waterstone, i have an experiment for you while you wait for your loupe.

grind at 25 degrees with the 240k diamond hone (if you're using a guide - I think you said you were), use your guide and iron for a full minute on the finest diamond stone to make sure the grind scratches are 1200 grit.

Then, work the back of something flat (this should be done with something flat if you have an iron that is) that this is being done with on the 4k grit waterstone side, and then put the bevel of the tool on the waterstone, lift it only a very small amount and pull it 5-10 times, being careful not to roll it steeper. Work the back lightly on the waterstone again and then pull it once at the same angle on your strop.

work it briskly on your pants or palm then (something with no abrasive), and then check sharpness. It should shave hair easily on both sides (something shaving hair only on one side is incompletely sharpened or hasn't had the burr removed).

If that's sharper than the agate edge, then you know you have issues.

a 1200 grit diamond hone (no matter how much someone tells you otherwise) will not create a finished edge and the wire edge is a bear to remove. If you do as paul does and take it off on a leather strop, you're just creating a half dull profile already as both sides will be rounded.

Charlesworth's method is far better for a beginner as it delineates each step better and you can take what you learn from it and run with it freehand later.