Oh boy, more bevel up vs. down fodder!

[C. in Indy]

This will be interesting to hear about!   From HNT Gordon:

https://www.youtube.com/watch?v=5v9X9Cgtl7c


A Part 2 is promised for this video, too.

[ESandvik]

Wasn't one of the biggest reasons for bevel up that you can change your blade angle by switching blades not beds? Not saying anything he's outlining is wrong, just that he might be beating on a strawman.

[Mike Brady]

He is addressing blade wear primarily and does not deal with planing "difficult" woods or different metallurgy.  Not to disagree with anything he or his sources said, but he basically is supporting his product's attributes by disqualifying other's.  I watched the next video of his about sharpening a nicker on his joinery plane.  Glad I don't have that tool to maintain!

[Derek Cohen]

That video was posted recently on both the Australian and SMC forums. I stepped in on the Australian forum because there were guys ready to accept the information on the video, and this information was based on flawed data. The video is presented by Terry Gordon of HNT Gordon planes. He is a good guy, but I think led astray by the data. I came in for some flack initially, as some do not like their hero diminished (I know Terry reasonably well, and I was not attacking him, but the data). Eventually, enough real data came out to demonstrate that the video was incorrect in its assumptions.

If you want the details, go to the Ubeaut forum: http://www.woodworkforums.com/f152/hnt-g...les-207302

Regards from Perth

Derek

[KlausK.]

Hi Derek,

thanks for the link to the Australian forum. Although you've got some bashing there, I agree with your conclusions. In theory the video from Terry Gordon is very plausible and his conclusions seem to be pretty clear. You pointed out, that the blade wear might be totally different from the cardwood patterns that are the base of Terry's conclusions. I'm with you to doubt that these cardwood patterns are telling the full truth. But my doubts aren't based on a serious knowledge as I have to admit. It's more the voice of my stomach that is speaking. It would be worth to investigate this phenomenon on a scientific level.

Klaus

[HomerLee]

Thanks for the link Derek! Read about half and added to my favorites to finish later. This may be an excuse to buy another plane (if I can find a place to put it).

[Derek Cohen]

Hi Klaus

Just to repeat for those who will not read the Ubeaut thread ...

Before one begins to question the ability of a handplane - or, lose confidence and pleasure in using the handplane they cherish -  first check that it is set up appropriately for the wood/grain involved. Before blaming the tool, ensure that user error is not the deciding factor. For example, is the blade sharp, is the bevel at the desired angle, and have you attended to the important set up details?

All planes are a compromise. High cutting angles are easier to set up than a chipbreaker, but their finish is not as clear, and this is even more apparent on softer woods. I can plane without consideration any longer to grain direction with a chipbreakered plane - which makes planing book-matched panels much easier - but more care is needed when setting up the plane. It gets easier with use. I am not trying to sell the chipbreaker here, just trying to point out pros and cons. I would still recommend a BU plane for a beginner who uses a honing guide. I would recommend a high angle BD plane for someone who does not wish to fiddle with settings. 

With regard the research on wear bevels, they are a reality. But we do not really know to what degree they intrude. We have a reasonable idea on BD planes since there is some reliable research described by Steve Elliott. The research that Terry Gordon used was the extrapolations (guesses) of Brent Beach, based on his toy microscope, which has serious limitations as far as deductive work is to be done (I have the same one, so I know). This suggested a greater amount of wear on the back of a plane blade. What all these research pieces omit is that - as far as I am aware - there has NOT been any similar studies on BU planes. Extrapolating from BD research for BU planes is unacceptable. 

I could say more, but that is enough under these circumstances.

Regards from Perth

Derek

[Alan S]

Extrapolating from BD research for BU planes is unacceptable.

The part I did not quote was well put and reasonable, but I must quibble with the quoted part.  In many cases the attack angle and relief angle of bevel up and down planes are similar or identical.  In those cases I would expect the wear bevels to be similar as well.  Differences would appear in the way one would deal with them in sharpening, but I don't see a problem in applying what was learned in one context to another, as long as you actually think about the experiment rather than simply transferring conclusions.

[KlausK.]

Hi Derek,

there are 2 points I want to mention. If the wear bevel on a BU plane would look like the cardbord pattern shows, how could a block plane work then properly? I didn't notice so far that block planes have to be sharpened more often than bench BD planes. Nor did I notice that my BU planes from LV need more sharpening attention.

A correctly set and sharpened double ironed BD plane will do great smoothing work. But a correctly sharpened single iron BD plane produces at least the same quality if the mouth is very tight. My hands down best smoothers are 2 single ironed kit planes from Ron Brese and from Gerd Fritsche (both are angeled at 55 degrees). Not only that they don't care changing grain direction that much but the surface quality they leave can't be better to my understanding.

Klaus

[Derek Cohen]

Extrapolating from BD research for BU planes is unacceptable.

The part I did not quote was well put and reasonable, but I must quibble with the quoted part.  In many cases the attack angle and relief angle of bevel up and down planes are similar or identical.  In those cases I would expect the wear bevels to be similar as well.  Differences would appear in the way one would deal with them in sharpening, but I don't see a problem in applying what was learned in one context to another, as long as you actually think about the experiment rather than simply transferring conclusions.

Hi Alan

Hopefully you will accept that relief angles and bevel angles differ between BU and BD planes. Generally BU planes have a 12 degree bed, whole most BD planes range between 45 degrees (common angle) to 60 degrees. 

In addition, I  consider that the vector forces on a BU and BD plane are different.

Not to forget that the research has only been done with BD planes, where the blade is orientated 180 degrees the other way.

I would say that one might make an educated guess, but this remains a guess. No one, as far as I am aware, has specifically investigated the wear bevel factors on BU planes.

Regards from Perth

Derek