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Forum topic by steve posted 367 days ago 1755 views 0 times favorited 59 replies Add to Favorites Watch
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steve

337 posts in 596 days


367 days ago

.

-- steve/USA


59 replies so far

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TobyC

461 posts in 478 days


#1 posted 367 days ago

So you want a war! Just kidding, I pretty much agree as long as the part at the edge is flat, and the back doesn’t have a twist or a concavity.

-- Cigarettes and squirrels are completely harmless until you put one in your mouth and light it up.

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steve

337 posts in 596 days


#2 posted 367 days ago

Agree…it has to be a “true” use-able tool to begin with…
I flatten all my irons, chisels, but I don’t over anal-ize it.

-- steve/USA

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steve

337 posts in 596 days


#3 posted 367 days ago

Getting used to a war on every post.
People (in General), not all want to fight. Ha! I admire the guts, but relax…it’s mostly a My shop/Your Shop Opinion, jeez…be cool, :)

This is a Forum…a forum of opinions…onions…lettuce, let us be civil! :)

-- steve/USA

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realcowtown_eric

288 posts in 540 days


#4 posted 367 days ago

Not to argue, but there are applications and there are applications.

Some of which will tolerate a touch of back bevel, and indeed function better with that…
I think of my adzes, where the mere touch of a back bevel allows the “wedge to ease itself up and out, instead of digging in.

The simplistic description of a wedge that steve describes implies that there are equal forces on both sides, but we all know there ain’t…maybe a mere 1/10th of a mm on one side, but an inch or two on the other side. The physics of a simple wedge cannot apply without considering the forces directing that force.

OTOH, if yer paring edge banding off of a panel with a 1/32 veneer, yer back better be absolutely flat.

And if you have to pare a 1/4 mm off of a tenon on an expensive antique undergoing repair, you want to be certain that the first chisel you use has the same characteristics of the one you pick up next, and will cut the same. Easiest to do if the back is flat on each and every chisel. OTOH, you might be able to fuss around with variably sharpened chisels trying to find the one that will follow a flat…till you found one that worked.

Besides, when yer sharpening the chisels, how do you figure out how much out of flat the bottom is, so as to take off the wire edge.

I however appreciate and understand where yer coming from steve, some of my carving tools, adzes, and particularly the power carving tools have a deliberate back-bevel (unflattness) to allow them to defect up instead of down….And when I’m rehabbing old tools, sometimes I just do the best I can, and hope for flatness in future rehabs. There is a law of diminishing returns, and sometimes you just have to accept a less than perfect , but perfectly usable result.

Eric in Cowtown.

-- Real_cowtown_eric

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steve

337 posts in 596 days


#5 posted 367 days ago

I am simply saying “I” am not SO ANAL about a flat back.
I wish I had the time back for deleting this.
So, I will not watch it no more…have at it.

-- steve/USA

View Bernie's profile

Bernie

414 posts in 1440 days


#6 posted 367 days ago

All my chisels have a flat back – never touch the back except for stropping to get the burrs off. Most of my chisel work involves cutting off tenons to the flat surface or cleaning out dado cuts etc… If I encounter work that needs to be done with a beveled edge, I flip the chisel over and use the beveled side. But whatever you do with your chisels or however you want to sharpen them is OK with me. As the old saying goes… “there’s more then one way to skin a cat”.

-- Bernie: It never gets hot or cold in New Hampshire, just seasonal!

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planeBill

467 posts in 1012 days


#7 posted 366 days ago

Hell, I just flatten about a 1/4” or so behind the edge and mine work fine. I may stray a bit further but all Im ever really concerned with is just behind the “0” point, call it good..

-- I was born at a very young age, as I grew up, I got older.

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TCCcabinetmaker

925 posts in 957 days


#8 posted 366 days ago

eh that’s just one arguement for worrying about flat… truth is it has to do a bit with sharpening to, a chisel isn’t as sharp without a flat line to hone to.

-- The mark of a good carpenter is not how few mistakes he makes, but rather how well he fixes them.

View Tony_S's profile

Tony_S

416 posts in 1686 days


#9 posted 366 days ago

??

You make a post that you know damn well is going to be controversial…..

”…So I’m sure this post will ruffle some feathers with flat back worshipers ”

One person ‘slightly and politely’ disagrees with you…and you snatch up your chisels and stomp off?

”I wish I had the time back for deleting this. So, I will not watch it no more…have at it.”

Bizarre to say the least…..

-- "The trouble with people idiot-proofing things, is the resulting evolution of the idiot."

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richardwootton

1094 posts in 558 days


#10 posted 366 days ago

Tony I was thinking the same thing. Looked like someone was hitting the bottle (not to mention any names) when that post came to life! I’m not judging, just blindly speculating… ;)

-- Richard, Hot Springs, Ar -- Galoot In Training

View lj61673's profile

lj61673

231 posts in 1002 days


#11 posted 366 days ago

Steve, the reason the back of any blade needs to be flat has nothing to do with a “wedge” or “geometry” or arguing.

It has everything to do with sharpness. Two points intersecting cannot produce a sharp edge if one of them is not flat. Simple. It’s just a physical fact.

So, while you are certainly entitled to your opinion, know that making statements that refute scientific fact does not constitute “thinking outside the box”.

Having said that, do whatever YOU thinks works for YOU. Be safe and enjoy….

View 8iowa's profile

8iowa

1489 posts in 2364 days


#12 posted 366 days ago

Since it takes two surfaces to make an edge, I flatten and polish the back, but no more than about 3/8 to 1/2 inch. This is also my procedure on plane irons.

Lately, I’ve been sharpening the bevels at 25 degrees and then applying a slight micro bevel. This makes it easier to quickly “dress up” an edge by hand while I’m working.

-- "Heaven is North of the Bridge"

View Fred Hargis's profile

Fred Hargis

1651 posts in 1096 days


#13 posted 366 days ago

“Steve, the reason the back of any blade needs to be flat has nothing to do with a “wedge” or “geometry” or arguing.

It has everything to do with sharpness. Two points intersecting cannot produce a sharp edge if one of them is not flat. Simple. It’s just a physical fact.”

That was always my understanding….it was tied to the sharpness. Same with plane blades.

-- I long for the days when Coke was a cola, and a joint was a bad place to be (Merle Haggard)

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planeBill

467 posts in 1012 days


#14 posted 366 days ago

That’s basically what I was saying. It just needs to be flat just behind the edge so you can achieve the theoretical ) 0 radius edge. Take a look at Japanese chisels, there is only a small amount of flat surface in front of the ura and behind the cutting edge.

-- I was born at a very young age, as I grew up, I got older.

View DocK16's profile

DocK16

1139 posts in 2689 days


#15 posted 366 days ago

Sorry but your premise for a flat back as being a reference for choppin and paring is wrong from the start. Fred and lj have it right it all about sharpness and the meeting of two edges. If your back isn’t flat your tool will never be as sharp as it could be. Like Fred said, no argument just fact.

-- Common sense is so rare anymore when you do see it, it looks like pure genius.

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