Razor sharp or with a burr ?

[BlackbuttWA]

After a heap of reading & watching Youtubes I have a question.

Skew chisels are very sharp with a honed cutting edge.

If the Negative Rake Scraper (NRS) is really a Skew chisel with a new name why is it many people say sharpen the NRS with a burr ?
I have noticed that this opinion is usually from USA sites & a few from the UK.

BTW....I have just shaped my skew with a radius cutting edge. It is terrific. IMHO

Cheers
Col

[China]

Never heard of that, I sharpen to a edge

[Richard Hodsdon]

If you have a look at Steve Jones "Mr Woodturner" on Facebook honing is unnecessary. He uses his skew straight off the grindstone. A pink 100 grit I think. An he is very professional. I don't hone my skews scrapers and they work. Al Stirt takes off the burr and turns the edge to get a consistent "burr" for his shear scraping . So I guess you it depends on what you want to do.

[NeilS]

I periodically go back to the grinder and use unhoned after that without a burr.

In between I raise a burr with a diamond hone. I might do this a half a dozen times before returning to the grinder.

The burr is more fragile and doesn't last as long, but is quick to reestablish and get back to scraping again.

Eventually a regrind is needed to maintain an acute angle.

There are no rights or wrongs with this, IMO, just preferences.

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[Skew ChiDAMN!!]

I've found that on the timbers I tend to turn (almost all Aus. HW) the burr disappears so fast that I may as well not have bothered raising it in the first place. Ditto with honing... the advantages gained by a honed edge are often shorter-lived than the time spent honing!

So I rarely bother and generally use my tools straight off the wheel.

Except for occasional finishing cuts where I am only cleaning up the surface, not shaping. Then a honed skew or burred NRS can make a real difference... and even then it depends heavily on the type of timber and crankiness of the grain. :shrug:

It doesn't take long before you learn which timbers prefer which type of approach; there is no universal method.

[Paul39]

I do what Skew does. Agreed, every timber is different, some even within the same bowl. I sharpen my flat top scrapers upside down, so I get an automatic burr, to get a negative rake I tilt down. With some timbers for the last finishing cuts, I sharpen upside down then hone off the burr with a piece of 320 grit flat on the lathe bed, taking the very lightest cuts.

Spindles are tool handles I make for myself, they ain't gonna hang in the Louvre.

[tony_A]

There's a thread running on Sawmill Creek at the minute covering sharpening of scrapers, particularly NRS. This may be one of the US sites to which the OP refers but it covers several aspects of his questions.
https://sawmillcreek.org/showthread.php?264955-Scraper-Questions

I only use a NRS for final very light finishing cuts to remove tool marks and torn grain. Also use shear scraper technique for torn grain but I don't quite have the tool control and still tend to leave fine ridges. When using the NRS for fine finishing cuts I want a fresh burr so it gives a clean cut and makes super fine wispy shavings. Don't get many passes with it but as the burr disappears the tool starts to tear the grain in the places with torn grain and I find I have to push harder to get it to cut.
Shear scraping also works on the burr on the tool. I find that I can use a burnishing rod to raise the burr on the scraper several times between grinds. Burnishing is quick and saves tool steel, particularly when you only get a couple of passes.

Tony

[dai sensei]

The burr lasts less than 5 seconds on our timbers. I do however hone my neg raked scraper and my bowl gouge when I am attacking difficult tear out timbers

[NeilS]

I only use a NRS for final very light finishing cuts to remove tool marks

...

When using the NRS for fine finishing cuts I want a fresh burr so it gives a clean cut and makes super fine wispy shavings.



Ditto

Different story if you are using a scraper to shape (I don't myself), in which case spending time raising a burr will be counter productive.

Contrary to the view of some 'purists', shaping with scrapers is a legitimate turning method. The old pattern makers all used it. I just find for myself that shaping with a cutting technique easier on my arms and shoulders than a heavy scraping technique.

PS - a burr turns a scraper into a cutting tool. But that is a topic that requires more explanation than is appropriate here.








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[glen.kempster]

I've found that on the timbers I tend to turn (almost all Aus. HW) the burr disappears so fast that I may as well not have bothered raising it in the first place. Ditto with honing... the advantages gained by a honed edge are often shorter-lived than the time spent honing!

So I rarely bother and generally use my tools straight off the wheel.

Except for occasional finishing cuts where I am only cleaning up the surface, not shaping. Then a honed skew or burred NRS can make a real difference... and even then it depends heavily on the type of timber and crankiness of the grain. :shrug:

It doesn't take long before you learn which timbers prefer which type of approach; there is no universal method.

I find the same thing.

Aus hardwoods murder a burr and give little reward for a honed edge. It's straight from the grinder for me too.

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