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robo hippy robo hippy is offline
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Default PING Robo Hippy re shear cutting

Well, a standard scraper will do the same thing. To get the glassy
smooth finsh, the gouge will work better because you are rubbing the
wood with the bevel and in effect, burnishing it (at least that is my
current theory which I reserve the right to change in the future if I
find out it doesn't work like I think it does now). You can get shear
and scraping cuts with both gouges and scrapers. If ground on the same
wheel, then you should get the same finish. Well, in theory that is. I
tried the gouge shear cut with the handle down and the blade up on my
bowls a lot, and never got the shiny cut that I would get with the
gouge rubbing the bevel. The same on the inside of the bowl. I have a
friend who uses a 'whisper cut' with a scraper on the inside of his
bowls for the final cut. By whisper, only the tinyest of shavings are
taken, the kind that hang in the air like 3 micron dust particles.
Well, I started trying it and it worked as long as my clumsy hands
didn't get too heavy. I started using the gouge more in a shear angle
and got a better cut. It still never looked as shiny as the rubbed
bevel cut. Once while spinning a bowl backwards to feel for tearout, I
notices very little with a freshly sharpened gouge. I couldn't feel it
when turning in the direction the bowl was spinning while turning. I
tried the same thing with a shear scraper cut, and got the same thing.
I also tried it with a shear gouge cut, and again the same thing. The
only real difference that I can find is in whether I am doing more of
a roughing cut rather than a whisper cut, and of course having a sharp
tool. This cut seems to be able to be used as a push or pull cut
regardless of whether you are on the inside or outside of the bowl.
For scrapers, I prefer the inside, or rounded off to the left side of
the gouge, and a 3/8 thick by 1 1/4 wide (I like big heavy tools).
Just roll it onto the side at about 45 degrees, and just barely touch
the wood. This is a clean up cut, not a stock removal cut. You need to
raise a good burr, and I do this with an 80 grit wheel, and push the
scraper into the wheel with some small amount of force, not just kiss
the surface. I also use a diamond stone to remove the old burr before
putting a new one on. I have tried the burnishers (hand held triangle,
and yes, I can push hard enough to raise a burr this way with the
triangle burnisher, but not with the round ones) without liking it as
much as the burr from the grinder. I currently have some bowls drying
that have been totally turned using a scraper (I turn green to final
thickness, and let them dry and warp before sanding and finishing). I
will sand them out this week, and see if the actual surface is any
smoother than the ones I was getting from the gouges. I can get a
satisfactory finish cut with a gouge on the outside of the bowl, but
the inside is never as good. Some days I do better than other, but the
inside always gives me fits.
robo hippy

On Jan 21, 1:40*pm, "TomNie" wrote:
One last thing I should probably add is that this problem started when I
started undercut edge bowls.

"TomNie" wrote in message

...

Robo
You answered the Oland Tool post with a shear cut remark.


I'm anal about a smooth, flowing finish but a find the scraper is not that
easy to just slide through a continuous cut. This could be my inexperience
trying to use that way. Further, since it's flat, I find it awkward to
bring up enough for a shear cut.


So, I'm thinking of a way too expensive tool at Klingspor's that has a
removable curving plus flat cutter attached to a stout round bar that has
some 1/4" flat on it. Seems this could be maneuvered a lot easier.


Your thoughts? Or anybody else's?


TomNie