Behavior of the dull (?) blade (bevel up vs. bevel down?)

[Paul Chapman]

Thanks Richard - some sanity at last :lol:

Cheers :wink:

Paul

 

[woodbloke]

Thanks Richard - some sanity at last :lol:

Cheers :wink:

Paul

Fabulous...a good read as always :wink: :lol: - Rob

 

[Mike H]

I don't believe it, what a palaver!

I have just been to touch up a blade that I blunted a bit this afternoon.

Including making sure the plane was perfectly adjusted, (LN 5 1/2), I just timed it at 2 minutes 40 seconds!

Most of the time was taking off and putting back, about 30 seconds on 2 grit sizes and a quick flat back.

We live in complicated times!

Mike

8)

 

[Derek Cohen (Perth Oz)]

Well I commend Adrian for discussing his experiences and raising his concerns on this forum. It takes a great deal of courage to admit when one does not understand something, and I respect him for doing so. There are members here who are being less than helpful, in fact downright rude and discouraging. Do you believe that your disparaging remarks will further Adrian's (or other readers) knowledge in any way, or motivate them to risk posting their questions on the forum?

The issue that Adrian raised is an extremely important one, and I emphasise this for those that lack the insight to recognise what this thread has been about. It is not simply about "sharpening" a dull blade. It is about what happens at the bevel when you use a BU plane blade.

There has been much theoretical analyses and too little practical investigation in this area to date. While some may argue that this endeavour is only for those with an enquiring mind, and that one should just use the plane, it is the results of enquiry that produces the fruits we serve up in the workshop in the way of improved methodology.

We need guys like Adrian around here. I think that some of you owe him an apology.

Regards from Perth

Derek

 

[Paul Chapman]

Blimey, Derek, get down off your high horse :wink: The original question has been more than adequately answered and explained, although after five pages of opinions it's probably quite difficult to find now......

Going round in ever-decreasing circles is not helpful, IMHO.

Cheers :wink:

Paul

 

[woodbloke]

Derek - your input on all matters on the forum is highly valued by myself and others, but these sorts of theoretical threads examining the minutia surrounding sharpening and honing etc simply do my head in. I know that you'll probably say ..."We'll don' t read them then" but I do, unfortunately.
At the end of the jour, the process ain't difficult and as has been said countless times hereabouts, we all need to find a way that works for the individual...if one doesn't, try something else that does and get planing wood.
No disrespect was intended to Aidrian (I did say my post was in jest) but after two threads and five pages I'm losing the will to live.

I'd be a lot more interested to see exactly what Adrian is trying to achieve with the timber - Rob

 

[bugbear]

I'd be a lot more interested to see exactly what Adrian is trying to achieve with the timber - Rob

He's just trying to get it flat (he said so in his first post).

I think the least helpful advice I've ever seen on sharpening was "just rub it on the stones until it's sharp, then use it"

BugBear

 

[Ikisumu]

Yeah I agree it went quite far. The scientific part especially. On the other hand, sometimes common sense needs to be supported by uncommon approaches.

If someone has a problem in something I see as clear thing as a Finnish vodka, the best way to start solving it is to make him write a list of things and methods he uses, in detail. If it is still not clear, make him chop down the listed details even further.

It's essentially his challenge and he needs to do his own part of his homework by himself. If the problem is real, the reason will eventually appear at least by trial and error. If not, I will personally start to think the poster is either a common troll, or he is really one of those very rare guys who really should have no business with tools and sharp edges whatsoever. However I think member Adrian is neither.

I have followed various discussion threads in different forums where some guy seems to be quite coherent all the way, but still nothing seems to work. Finally after several posts (and picking and whatnot) it was revealed that all of the stages of the work were conducted in proper order, but then one or two of those stages were taken a just bit too far or was done insufficiently, anyway just enough to ruin the entire thing. A beginner guy had no touch-feely on the thing at all, only tried to just follow some method.

I think member Adrian has/had problem with this that he just honed his microbevel way too far. A microbevel is indeed something like a 30 ... 500 micron wide region at the edge. Making this takes really only a few pushes, some tens of seconds maybe and that's it.

An uncommon sense is quite common after all, isn't it.

Samu

 

[Derek Cohen (Perth Oz)]

Paul wrote:

Going round in ever-decreasing circles is not helpful, IMHO.

Paul, we cannot have you getting dizzy. You'll do yourself a mischief! So just don't read the posts


Rob wrote:

these sorts of theoretical threads examining the minutia surrounding sharpening and honing etc simply do my head in. I know that you'll probably say ..."We'll don' t read them then" but I do, unfortunately.

Rob, this type of compulsive behaviour is treatable. In the meantime, just don't read them

Regards from Perth

Derek

 

[bugbear]

(I wonder if Jacob is reading this, and wanting to "contribute")

BugBear

 

[woodbloke]

Rob, this type of compulsive behaviour is treatable. In the meantime, just don't read them

Regards from Perth

Derek

Derek, you're spot again...it's called retirement :wink: - Rob

 

[adrian]

The issue that Adrian raised is an extremely important one, and I emphasise this for those that lack the insight to recognise what this thread has been about. It is not simply about "sharpening" a dull blade. It is about what happens at the bevel when you use a BU plane blade.

Many people clearly don't recognize this, but Derek has it right. The question was about why these planes seemed to behave so differently. And the various answers have clarified my thoughts and given me ideas for things I might try to further my understanding.

It's essentially his challenge and he needs to do his own part of his homework by himself. If the problem is real, the reason will eventually appear at least by trial and error.

Trial an error, completely undirected, is a slow way to learn. I'd prefer to at least limit the scope of trials by using the knowledge of others. And when it comes to understanding things that happen at a microscopic level, perhaps it's not effective at all as a learning technique. If all I wanted to do was make more shavings, then I don't have a real problem because I know that if I sharpen the blade it will make shavings again. The problem is more one of an intellectual character. Why do I observe such a big difference between my tools? And does this in the end suggest a way I should change my work practice?

There are some immediate implications for my method of work. In following the Charlesworth method for flattening timber, you're supposed to plane stop shavings until the plane stops cutting. So what am I to think when the plate stops cutting but the straight edge reveals a pronounced bump? It doesn't cut badly, tearing the work, or leaving lines. It just doesn't cut. As far as I can tell it went from nice shavings to no shavings. Understanding that the plane can stop cutting for other reasons that surface concavity is very useful.

Another implication concerns tool choice. If I can plane for 15 minutes with a bevel up plane or 4 hours with a bevel down plane before I have to sharpen, and I'm satisfied with the quality of the planed surface in either case, then I'd really prefer the 4 hours. (This would be true even if I can sharpen in 2 minutes because sharpening interrupts my flow.) This would present a strong reason to favor the bevel down. Maybe it would be worth double beveling to get higher cutting angles. If it's rather about cutting angle then maybe I need to carefully consider my need for the 59 degree cutting angle, or at least understand the trade off.

For those who want to hear about actual shavings, I'll report that I sharpened the blade. It took 10 minutes to work past the microbevel and I did more loupe inspections than I normally would to see if I could identify any residual wear bevels anywhere. As far as I could tell the edge looked good without a bevel on either side. I started with a 0.001" shaving and then raised it to 0.002" and finished flattening the board I've been working on. This took somewhere in the vicinity of 15 minutes and if the plane performance changed during that time, I was oblivious to the changes.

I'm making a side table and this board will be part of the apron. I need two short pieces more and then I'll have the stock preparation completed, and I can begin the joinery. I expected to start in on planing another board for the two short pieces, but the board had a rather large amount of twist, and I ended up getting caught up in the question of whether to cross cut it (to preserve thickness) or use different stock, or forge ahead. (I do also have the problem of planing the table top. It has some scary looking tear out and is 63" x 22".)

 

[Harbo]

I have been far too busy doing some actual woodworking so in a way have followed the advice given and not read it
Well not fully - but reading the last bit I think a scraper plane needs to be got ready

Back to the wood

Rod

 

[adrian]

I must admit that I haven't had much success with my scraper plane in general. I got it to actually cut by following Charlesworth's directions, but it didn't cut for long and I haven't really gotten the feel for adjusting it. What makes the tearout scary, by the way, is that it looks deep. There isn't much of it as the boards are generally well behaved except around a few tiny knots where the grain swirls.

 

[big soft moose]

(I wonder if Jacob is reading this, and wanting to "contribute")

BugBear

he is, if you look on the tother side, hes even started a thread about this thread.

mind you i agree with him (oh god is treatment available), and with paul and rob, its a plane blade - just sharpen it and then get on with working the wood.

I suspect that for some here the woodwork is fast becoming an excuse to work up these incredibly complex sharpening methodologies and theories.

my take is the old saw that good enough is good enough, but perfect is always a pain in the ass.