Has anyone attempted to sharpen a scraper in the reverse direction, in order
to raise a burr?

Walter H. Klaus

Actually, Walter, it is fairly common to sharpen a scraper backwards or
upside down or whatever way you wish to espress it, in order to raise a
larger burr. Just incline the grinder table to about 10 to 20 degrees off
the parallel and go to it.

--
God bless and safe turning
Darrell Feltmate
Truro, NS Canada
www.aroundthewoods.com

"Walter H. Klaus" wrote in message
...
Has anyone attempted to sharpen a scraper in the reverse direction, in
order to raise a burr?


It'll give a coarser, presumably longer-toothed burr than conventional face
up, but it carries a couple of disadvantages with it. First, it'll be gone
sooner, second, while it's there, it'll be aggressive as hell. Might also
take a bit more of nose down to engage your burr. Lot of talk about
"negative rake" scrapers in other places right now. Must have been an
article somewhere recently. With a small reverse grind near the upper
surface, they should be more stable than the conventional grind - some bevel
to stabilize - making it easier to take a thin broad scrape rather than
"shear" presentation with its thin narrow.

Since a smooth edge scrapes as well as a rough one, if not better on fine
work, why not go burr-less? Then you hone only.

I bought a round nose scraper from Packard and the instructions that came
with it advised sharpening it backwards/upside down. The results work fine
for me when taking those final light cuts.


"Walter H. Klaus" wrote in message
...
Has anyone attempted to sharpen a scraper in the reverse direction, in
order
to raise a burr?

Walter H. Klaus

I bought a round nose scraper from Packard and the instructions that came
with it advised sharpening it backwards/upside down. The results work fine
for me when taking those final light cuts.

I watched Eli Avisera sharpen his that way.

I bought a round nose scraper from Packard and the instructions that came
with it advised sharpening it backwards/upside down. The results work fine
for me when taking those final light cuts.

I watched Eli Avisera sharpen his that way.

Right. It causes a burr to form, which does the scraping. The other way to make
a burr is to form one using a burnisher. Scrapers remove wood by... scraping,
not cutting.

Thank you for responding.

Walter H. Klaus


"Walter H. Klaus" wrote in message
...
Has anyone attempted to sharpen a scraper in the reverse direction, in
order to raise a burr?

Walter H. Klaus

Hi there

I think we are comparing apples with oranges here, the problem is with
the different metals, they do not behave the same under the same
conditioning, some will flow better than others depending what and how
much other metals are in the steel we have.

Almost all the tool steels are developed for the metal industry, and
cutting metal is a lot different than wood.

So rather than going into the metallurgy and guessing what is in your
steel, and how it might behave, I would say try to grind the tool first
the normal way, and than another way, compare and go from there, my
experience with my scrapers is it takes 2 seconds to sharpen and 2
seconds to get them dull again, I don't turn off my grinder if I want
to get a fair surface, and take longer between sharpening if I have to
just get some bulk out of there.

As for the negative rake on scrapers, it works a lot like holding a
scraper with it's nose down steeply, but without getting the tool
jammed between the tool rest and the wood, or as using a scraper
freehand in the 7 o'clock positioning to cleanup the outside of a
turning, just makes for a less dig in prone scraper, thats my take on
it.

Have fun and take care
Leo Van Der Loo

"Dan Bollinger" skrev i melding
m...
I bought a round nose scraper from Packard and the instructions
that came
with it advised sharpening it backwards/upside down. The
results work fine
for me when taking those final light cuts.

I watched Eli Avisera sharpen his that way.

Right. It causes a burr to form, which does the scraping. The
other way to make a burr is to form one using a burnisher.
Scrapers remove wood by... scraping, not cutting.


(dare, dare not, dare, dare not; oh ****)
I would think that to be right, - if they are sufficiently dull.
I sharpen my scraper (yes, I have only one) to a bevel of
about 80 degrees, and finish the flat side with a diamond hone.
It cuts off hairthin shaves with almost no breakage of fibers
in the problem spots when presented to the wood like
a cutting iron.

I would think, also, that the metal of your scrapers would
have to be rather soft to form this burr you are talking about?

BjarteR

(dare, dare not, dare, dare not; oh ****)
I would think that to be right, - if they are sufficiently dull.
I sharpen my scraper (yes, I have only one) to a bevel of
about 80 degrees, and finish the flat side with a diamond hone.
It cuts off hairthin shaves with almost no breakage of fibers
in the problem spots when presented to the wood like
a cutting iron.

I would think, also, that the metal of your scrapers would
have to be rather soft to form this burr you are talking about?

BjarteR

I have seen some 'scrapers' sharpened to 60°, but then its no longer a scraper,
but a chisel, isn't it? I know of others who remove the burr like you. Still
other who remove the burr caused by grinding only to put a burr back on with a
burnisher. We know from your description that you are using the tool to scrape,
and not to cut, by your description of how you hold the tool (handle tilted
upward slightly). Grinding produces burrs regardless of the metallurgy. The
size of the burr depends on how your present the steel to the stone.

Dan

On Wed, 3 May 2006 19:00:00 -0500, "Walter H. Klaus"
wrote:

Has anyone attempted to sharpen a scraper in the reverse direction, in order
to raise a burr?

Nope. But I do see a pronounced burr grinding them the "standard" (if
there is such a thing) way.

But if you're looking for a sharper tool for the finishing cuts, I'm
still a really big fan of a carbon steel scraper. They don't stay
sharp nearly as long as a fancy HSS one, but boy do they shear fibers
smoothly- and they're cheap. I'd worry about a ragged burr from
stretching the metal by sharpening upside down, and my inclination is
to go with the metal that gets sharper if I want a smoother or more
agressive cut.

Then again, there are no set rules for any of this. Give it a try,
and let us know how it works.