Down Side of Bevel Up?

[Hans Braul]

After having used my LV bevel up Jack for a couple of months now, I am realizing there may be a down side that I did not appreciate at first. Or, it may just be I need to adjust my planing method...

When drawing the plane towards me for the next push, I don't lift the plane off the piece (lazy, I guess). So the flat back of the blade gets worn, especially in tough hardwood like curly maple. With a bit of magnification this wear is quite visible.

Normally, to rehone a blade, a few passes on the microbevel an 8000x stone followed by a swipe or two on the back to remove burr, and I'd be good to go, right? Not if there is wear as I've described! To restore the edge, I must either polish the back for a LONG time, or remove quite a bit of material from the bevel to get the edge back to before the wear started. Either way I'm removing a lot of material and spending more time than I'd like. If it were a bevel-down plane, I think restoring the edge would require much less removal of material.

Is this correct, or am I out to lunch? In the meantime, I think I'll adjust my habit of dragging the plane over the material. I'd love to hear from the hand-plane experts out there on this one.

Cheers
Hans

[Brian Hale]

I've noticed the same "back bevel" on my BU jointer caused by dragging it backwards. To stop it I generally just rock the plane to the side a bit or pick up the heel and drag the toe back.

I guess the proper way is to pick it up at the end of a stroke but.......

Brian :)

[Steve Elliott]

The wear on the lower surface of your blade comes mostly from the forward planing stroke, not from dragging the plane back. Having more wear occur on the back of the blade is a disadvantage of all bevel-up planes. The shape of a worn edge is not symmetrical--greater wear occurs on the lower side that slides over the newly-planed surface as soon as the blade loses any sharpness at all. On bevel-down planes this wear surface can be removed by honing the bevel a moderate amount, but on a bevel-up plane blade the bevel must be ground back considerably farther to remove the worn area.

There's a drawing of a worn edge profile on my website at http://bladetest.infillplane.com/html/wear_profiles.html and a longer discussion of bevel-up blade sharpening on Brent Beach's site at http://www3.telus.net/BrentBeach/Sharpen/bevel%20up.html.

[David Marcus Brown]

I agree that there is a downside to bevel up. I no longer see it as the panacea I used to imagine it to be. You are right about the wear to the back of the blade from use. Whether it's from dragging the plane on the back stroke (doubtbul) or from the scrubbing action of the wood inherent in a bevel up design, it's not your imagination.

After a few sharpenings just honing the primary and secondary bevels (ignoring the back that had been flattened initially) I noticed that the cutting action was degrading precipitously. Annoyed, I checked out the back of the blade, saw the wear and honed the back of the blade using Charlesworth's ruler trick. The cutting action improved but having to take that extra step really bugged me.

I still use my bevel-ups, just not as much as I once did.

:rolleyes:

[Mark Singer]

When bringing the plane back...twist a little just to lift the iron off the wood..

[Joel Moskowitz]

I am convinced that this is why, while the first wave of metal planes were of bevel up design (mitre planes) the wave that became and remained popular was the bevel down design. The more you use the plane of course the more prominent and annoying the wear bevel on the back is.

[Raymond Stanley]

I wonder too, after prolonged use, if the greater back-honing will make the blade have a rather un-uniform, unflat back. This could cause a less solid seating on the...thing that it sits on. Then we could get chatter problems, when bevel-up planes are so great for not having these (as compared to a bevel-down plane). I'm a novice, though so I may have no idea what I'm talking about.
Hans, don't be sad. In my novice opinion and great experience, they are still great planes. I have a Low Angle Jack that I absolutely love. Just a wee more back-honing. A bedrock style bevel-down plane would require a wee more effort to move the frog than the bevel-up.

There is an interesting discussion on the oldtools archive that discussed bevel up vs. bevel down, if you are interested in more info on the subject.

-Ray

Edit: sorry about the direct link!

[Alice Frampton]

Yep, this is the drawback and one I started to draw attention to a while ago. Unfortunately the reaction of some folks to mentioning them at all meant I stopped posting about both the pros and the cons - which goes to show something or other. Personally I think A2 irons are a positive disadvantage in BUs for this very reason, while being a new plane user and thus likely to be more careful about your sharpening is probably an advantage. It's not a deal breaker - they still have so many plus points - but it's something you need to be aware of. Heck, did you really think there was a perfect plane out there with no downside? I wish. :rolleyes:

Cheers, Alf

[Hans Braul]

Great replies - thanks to all. Brent Beach implies there should be a different sharpening regime for BU blades, but I couldn't find what that actually is. Any advice for how to sharpen BU blades differently from bevel down?

Derek Cohen, are you there? I'd love to hear what you have experienced on this.

Also if Rob Lee is reading, what's your advice?

Cheers
Hans

Many thanks
Hans

[Robert Trotter]

Hans, I had a look at Brent's site and from what I gather from there and from Derek's posts somewhere, the new regime is to use back bevels. Have your main bevel and micro bevel on the "bevel" and also put a slight back bevel on the blade. Then when touching up or resharpening you need to do the front bevel and the back microbevels. THe bac bevel just removes the wear bevel as he calls it and this will really remove no extra metal. You don't need to use up lots of blade trying to remove the wear bevel. From what I understand for bevel down blades you basically work on the bevel side only and rarely work the back.

So back bevels are the way to go from what I read.

Robert

[David Marcus Brown]

Have your main bevel and micro bevel on the "bevel" and also put a slight back bevel on the blade. Then when touching up or resharpening you need to do the front bevel and the back microbevels. THe bac bevel just removes the wear bevel as he calls it and this will really remove no extra metal. You don't need to use up lots of blade trying to remove the wear bevel. From what I understand for bevel down blades you basically work on the bevel side only and rarely work the back.

So back bevels are the way to go from what I read.

Robert

This advice definitely parallels my own experience. The back won't need work every time you hone and the backbevel only need be 1/2 to 1 degree or so. Just enough to get rid of the wear on the back of the blade. Look online for David Charlesworth's "ruler trick."

[Jules Dominguez]

The Veritas Mk II honing guide provides a setup for honing back bevels, down to a minimum angle of 1 degree. I haven't used that feature yet for my bevel-up blades, but probably will in the future.

[Pam Niedermayer]

Great replies - thanks to all. Brent Beach implies there should be a different sharpening regime for BU blades, but I couldn't find what that actually is. Any advice for how to sharpen BU blades differently from bevel down?...

The only metal bench bu plane I have is the LN LA Jack, which I love as a first/second plane, as well as a go to general purpose when I get lazy. I lift all planes on the back stroke, not that I'm sure it matters vis a vis dulling, just from an efficiency standpoint (easier to move a plane through air than across wood). On the LN, I simply hone the bevel and then the back, the full back. No problems, only takes a couple of minutes.

Pam

[Jules Dominguez]

Pam, I'd think that would take a longer time. Do you hone the full bevel also, and how do you do the honing?

[Pam Niedermayer]

Nope, didn't take long at all. At the time I was using the LN a lot I was using scary sharp. Oh, yeah, no A2 in this shop.

Pam

[Derek Cohen]

Hans, I had a look at Brent's site and from what I gather from there and from Derek's posts somewhere, the new regime is to use back bevels. Have your main bevel and micro bevel on the "bevel" and also put a slight back bevel on the blade. Then when touching up or resharpening you need to do the front bevel and the back microbevels. THe bac bevel just removes the wear bevel as he calls it and this will really remove no extra metal. You don't need to use up lots of blade trying to remove the wear bevel. From what I understand for bevel down blades you basically work on the bevel side only and rarely work the back.

So back bevels are the way to go from what I read.

Hi Robert

That is an excellent summary. Spot on!

We have been saying for a while now that BU blades do not retain their edge as long as a BD blade. Still, in a world of pros and cons, the pros of the BU configuration continue to clearly outweigh the cons. Honing a BU blade should only take a minute or two, so we are not really looking at much down time.

Honing a BU blade involves a microbevel on the front using the Veritas Honing Guide Mk II: first a 1 degree turn on the cam roller for the first microbevel on the 1200 waterstone, then a 2 degree turn on the 8000 waterstone for the second microbevel. Remove the blade, flip onto its back and it is time to add a micro backbevel of just under 1 degree using David Charlesworth's "Ruler Trick".

I consider the strength of the BU design is for smoothing. The second negative feature of this configuration is the difficulty in putting camber on the blade. It is done, but a greater amount is required than with a BD blade. This is simply due to the angle at which the bevel is presented to the wood. Consequently, for blades that benefit from moderate or greater camber (scrub plane, hogging jack plane), I generally prefer BD planes.

Of course, the versatility of the BU design is what first grabs most buyers. That is, the ability to dial in the cutting angle of choice. For an Australian, this proves beneficial since we are generally needing high - and very high - cutting angles. The abrasive nature of many of our indigenous timbers also means that we benefit from blades that hold an edge longer, and we have seen very durable HSS blades coming from makers such as Academy Blades. The A2 steel is probably a better compromise between edge holding and honing ease.

What is in danger of being lost in this mix is the "feel" of a BU plane. My experience is that I obtain a greater sense of immediacy than when using a BU plane. This comes from its lower centre of gravity (compared to a BD plane). Larry Williams once wrote in a reply to me that the advantage of the higher centre of gravity of (his) woodies was the improved accuracy of plane orientation (such as when jointing). I accept this. My analogy is that this is similar to using a long mortice chisel. One can sight angles better. But this is at the expense of feel. There is no right or wrong here, no better or worse, just a preference of use.

I do use BD planes as much as BU planes and with these my sharpening strategy is quite different. Here I prefer softer HCS blades since I will hollow grind and freehand hone, and this is made possible since there is a better wear pattern in the BD mode.

After Christmas, when I take some leave and have more time, I plan to compare the experience of using a few BU and BD planes - not a shoot out as to which is "better". It will be interesting to contrast the feel of the Marcou BU smoother, the Veritas BUS, the LN #4 1/2 bronze and iron smoothers, and a traditional Spier infill.

Regards from Perth

Derek

[Hans Braul]

Derek

Thank you so much for your response. I was hoping you'd weigh in. It is gratifying to know that when I encounter a problem, I think about it some, and come up with what I think is the root cause, and people like yourself with much more experience than I confirm that I am indeed not crazy.

Very helpful indeed.

Regards from the colder of the colonies.

Hans