Thread: Unicorn in depth article

Hi David. Just read your Woodcentral article and have just purchased a cotton wheel. Ready and raring to go. Do you think the green Veritas compound will be okay? Other options are a no name green and a no name red.

Veritas green is good, other green is probably good as long as the price is not really high. Really high price bars may be pure chrome ox...too slow.

Red could also be pure iron oxide...too slow.

Thanks for preserving with this - I am soaking it up and having limited success.

I don't think I am getting it quite as sharp as when I hone with a stone and strop. But it does seem to last.

Still making sense of it all and working on consistency. You make it look easy in the videos - I' don't. But I will persist.

Thanks

Glenn

Planes (if they're really fully buffed) will have a very slight loss of that stupid keen sharpness at the outset, but in anything less than ideal planing, they'll make up for it in edge toughness.

For chisels, this is kind of like using the cap iron. What's right on the cap iron isn't a specific setting or number, but rather what's in between two "wrongs". you know to set it further away if it jams up and leaves a rough surface, and closer if it's not mitigating tearout. Between there's a comfortable range.

For chisels, with the buffer, you just have to find the feel where the chisel holds its edge better (if it doesn't, then more buffing is in order) and also where it's not harder through the wood (if it's harder through the wood and holding an edge well, then there's probably too much buffing).

I haven't been doing it for long, but experimentation has given me a lot of reps. Last weekend, I Planed a bunch of junk pine here with knots in it, and that also gave me a lot of practice. I think in squaring four 4x4 posts, I had to sharpen 8 times. Fortunately, that's only about 15 minutes, but those reps improve things. It just happens.

Every project isn't just a project, but a chance to apply this stuff and have an interesting diversion in the middle of the work (and a quick diversion, so it doesn't get in the way of getting things done). As I was planing this junk wood with the cap iron set, the shavings just flow over the side and lay on a jointing peg and the vise. Eventually, the pile gets too heavy at one end and falls down into this waterfall of pine shavings.

https://i.imgur.com/3EbmGfx.jpg

https://i.imgur.com/LrywSSt.jpg

It was really pleasant, even if the wood is junk (each 7 foot post will only have about $5.50 of wood in it - the knots are uncanny hard and the wood is definitely not).

David,

I'm on the cusp of unicorning a plane iron.

I'm... scared for my edge... but kind of excited.

The chisel I unicorned... it is still sharp. I don't feel I need to do anything to it?

Originally Posted by Cgcc

David,

I'm on the cusp of unicorning a plane iron.

I'm... scared for my edge... but kind of excited.

The chisel I unicorned... it is still sharp. I don't feel I need to do anything to it?

I guess eventually the chisel may get dull and you may not notice it occurring since it happens slow.

Only my lowest quality chisels have needed much attention in a shop session. The others, I haven't pushed to failure - they get hot in use rather than getting dull, and I'm guessing that's just the bevel rubbing its way through the wood as the chisels cut.

If it's been a while since you've sharpened a chisel, you can go through the steps (which will always involve completely removing the prior uni-bevel) and see if it feels much sharper.

That's the danger of all really long wearing tools - they can get dull so slowly you don't really notice. That's not much of a real danger, though!!

For plane irons, depending on which method you use (I called them 1 and 2 in my article), start with less buffing, and get the iron into the backbone of the wheel rather than taking things lightly. Experiment with speed in the wheel and feed as evenly as you can back and forth. Look at the edge after "less", and if the wire edge is still there, give it another pass. If the wire edge is removed, then it's ready for a go. On a full speed buffer, it feels kind of rough on the end of a tool, but it's really not - anything you manage to do to the iron can be honed off in a minute for another try.

Wilco. Will report back.

This all deserves more attention.

No worries - if it works well, then everyone who has luck with it tells a person or two and it spreads on its own.

There's a chance it may be in a print magazine here (but that's not my bag - I don't like paywalls. A few others are distilling parts into a shorter article and may see if it can be pitched to pay some of the ongoing expenses at wood central. And I think that's fine as long as it doesn't infringe on the long article being up for free).

For chisels, it works so well that I think it'll spread like a slow virus.

Hi Dave. Just had a go and WOW! Improvement is obvious. I will need to keep practising, like any skill. I removed the whole guard from that side of the grinder and I'm basically holding the chisel underneath the wheel, horizontal to the table.

I'm having good results except for end grain. For end grain I still need to finish on a stone and hone.

I expect its just me - so I'll keep on experimenting.

Cheers

Originally Posted by Fluddman

I'm having good results except for end grain. For end grain I still need to finish on a stone and hone.

I expect its just me - so I'll keep on experimenting.

Cheers

End grain Jacaranda ..



.. and Jarrah ...



This is a 25 degree bevel with a unicorn profile.

Regards from Perth

Derek

If I understand this correctly, this is essentially a convex bevel?
I have just tried this method out on my plane blade on one of my difficult to set #5 in that I can't get the blade to behave if I set the cap iron too close, so as a compromise, I set cap iron about 1mm away.
And I thought it would be a candidate to try out a convex bevel (unicorn?). I grind the primary bevel to 30° on a half-speed grinder, then hone it on my Tormek at 30~31° or thereabout, and then polish it with a 4000g Japanese wheel with a 33° secondary bevel. Finally buffed it on the Tormek leather honing wheel with Autosol at 40~45°.
I tried it on some very knotty cypress pine and I was very surprised how crisp it cut. I think it's very interesting, certainly worth giving it further thought, and experiment with different cap iron settings.

Originally Posted by derekcohen

End grain Jacaranda ..



.. and Jarrah ...



This is a 25 degree bevel with a unicorn profile.

Regards from Perth

Derek

Awh you're just showing off!

But nice work!

Thanks for the write up.

Maybe Im stupid or its been a long day - on your table the Figure #6 - less is "sharper' correct? (less no. of strikes required to complete the test).

Its interesting to see that on the unicorn bevel the japanese and iles mk2 did as well as the pmv11 but with better edge retention.

I know you said the narex chisels are no good in your video - where do you think they would sit compared to the ones in your test?

The youtuber woodbywright did a chisel test and the cryogenic narex chisels came out on top, beating the veritas pmv11 too. Here they are:

Robot Check

Also, can you describe the kitchen knife technique? Do you just go straight to the buff it its sharp but not sharp enough or do you need to use a stone first?

Last question Have you seen the technique where people use an MDF wheel charged with buffing compound in their grinder? What are your thoughts on that?