Log Peeling Draw Knife

[gmbobnick]

I have used 5 different draw knives for peeling logs (mostly loaners) all varying in terms of length, weight, handle design etc.  It’s given me an opportunity to look critically at the tool for the purpose of peeling logs.  Here is what I have learned for any who would want to make their own tool:

Weight:  One of the most critical factors.  Weight helps drive through bumps and small knots.  It produces a smooth cut with little or no chatter marks.  Weight is achieved obviously through blade thickness, width and length, but there is a nice balance, which are other factors to discuss.

Length:  Length adds weight, which is important to function.  But there is a point where greater length is not comfortable even if no longer useful for cutting.  I find an overall tool length at 20 or so inches to be about right for ergonomic comfort/fit.  It allows a nice direct pull from my shoulders, as I use my back for pulling more than my arms.  A blade-edge length of 12” works with this overall length as will be mentioned later.  The actual wood peel is only an inch or two wide so there is no relationship here to blade length.

Blade Width:  I don’t find any important issues with width other than for adding weight and stiffness…3 inches is fine.

Stiffness:  This is important.  Flex robs ability to cut a clean, flat swath.  Flex also diffuses the focus of force where I want it to be applied.  Virtually no flex is allowed within the range of force I am physically able to put on it.  I suppose it will flex minutely, but I don’t want to see it when I work the blade.

Thickness:  This factor goes to weight and rigidity.  I find about 3/8” is good for the size of knife that meets my length and stiffness criteria.

Handle Design:  Since I am pulling, some way to keep the handle from slipping my grip is obviously important, especially when working a hard spot.  I don’t want to grip the handle too hard to accomplish this, because after hours of peeling, your grip could crush the Pastors hand when you walk out of church service.  The handle doesn’t have to be complicated or fancy.  A shapely curve in the grip is nice and sensible, but not necessary.  I want the handle stem short enough so that I can hook a finger around the back of the knife for extra hold when I need it.  Otherwise a round/oval handle section about 5 inches long that fits the hand comfortably is fine.

Handle Angle:  Another important factor.  Its about ergonomics and being able to put downward pressure on the cutting edge as you pull.  A modest downward angle with respect to the blade flat is what I want.  Handles should also be splayed outward to help prevent slip and reduce stress on the wrist.  I can’t give design angles because that has to be custom fit for optimal results.  Designing how the handle attaches to the blade is important to allow that fit and adjustment.  See my closure to this post for how this can be done.

Bevel:  First the blade should only have a simple/single bevel on one side...like a chisel. I discovered that if you are going to cut with the bevel side down, it had better be dead-flat or slightly hollowed.  Any convexity…and I mean any.. will dramatically reduce cutting efficiency.  The edge will fight against itself as you pull.  I also discovered that I am still horrible at getting a nice grind whether flat or hollow.   But no worries.  One side of the blade is truly flat anyway.  Drawing with the bevel up produces satisfactory results.  Since I will be sharpening the blade in the field, I will be less likely to consistently keep a flat bevel over time, but not a problem if bevel is up.  Maybe not so much a problem sharpening with a hollow ground blade.  As for bevel angle …when cutting bevel side up…I say 25 to 27 degrees works fine on a flat grind.  I don’t feel compelled to experiment further unless maybe if I should want a blade that cuts bevel side down.

Handle to Edge Clearance:  Its good to have a gap of several (3 or so) inches between the handle and the end of the cutting edge.  This will allow working the blade edge into tight spots around knots or depressions.  I am thinking of maybe even putting a radius on the cutting edge on the corners to make it even better for that purpose…so I don’t have too sharp a point.

Steel:  Ahhh…the thing we all love the best about knives.  As with any other knife, there are many opinions about steel.  My thing is I want to keep the blade razor keen.  I like to sharpen.  Its comforting for me…like thumb sucking I suppose.  I sharpen frequently and I use a stone, so I want to feel like I can restore the edge quickly and consistently on a long blade…so not too hard of steel.  If you want a blade that cuts bevel side down, then I would advise a HARD blade so that less than perfect sharpening will not create convexity.  One knife I used cuts best bevel side down, but it was made from an industrial planer blade and it is HARD and stays flat and sharp a long, long time.  There isn’t anything demanding about toughness for peeling bark, so I don’t think that is a big issue. Frankly, I just don’t see where one needs to spend a great length of time researching and studying the best steel for this purpose, so long as it has at least a modest amount of carbon so that it can be hardened to whatever hardness ones heart desires, and kept sharp for at least a day of peeling.

That covers the key points I can think of.  Anyway, after experimenting with different knives I of course came up with my own.  I am delighted with it!  The one improvement I think is putting a beveled radius on the corners rather than a 90 corner.  I made it from a truck leaf spring, two ½-inch bolts and a piece of sledge hammer handle.  A useful part of this design is how the handles are fastened to the blade.  The attitude of the handles is easily tweaked to my liking.  Remove handles, clamp the blade in a vice at the end of the cutting edge (I like to think the vise jaws act like a heat sink), torch the twist and adjust as needed…without messing with blade properties.

I am curious what any others out there have found about design and construction of such a tool.  Let me know!

[JHCC]

Anyone ever tried a pistol-grip shape for a drawknife?

[Frosty]

That  is a darned good write up, thank you. It only needs better illustration to be darned near perfect. The one picture doesn't show the points you make clearly. I can see the blade's width and thickness pretty well but not the bevel nor a good representation of the handle's angles or radius. 

I've used draw knives to peal bark and dress two sided logs. Not recently mind everybody, I haven't participated in log construction since the early mid 70's. I still have my draw knives, it's in my packrat nature to not let tools go. I know about where they are but that'd be an adventure in the Connex I'd rather not have, to make comparisons so I have something  on which to base what you're saying. 

I'm just asking for a couple pics from different angles so we can see what you're talking about. Maybe one of the bevel with the knife laying flat, straight down might show the curved transition you describe too.  One from the end should show the angle of the handles to the blade. You have the knives and understand what you're saying above, my use is 50 years old so my understanding is dated to the point I'm mostly guessing at what I'd like to see. I'm not criticizing, I'd just like a clearer idea of what you're saying. 

 Frosty The Lucky.

[gmbobnick]

2 hours ago, Frosty said:

I'm just asking for a couple pics from different angles so we can see what you're talking about.

For sure!  This gives me an excuse to escape my "social distancing" office and get some fresh air.  The photo quality isn't as good, but should help.  I used a piece of electrician's tape to show what I meant about the radius in the first photo.

[Frosty]

Those do it nicely! Thank for the pics and you're welcome for an excuse to get some air. I just hope you jogged, we're supposed to be getting some . . .<shudder!> exercise! <GASP>

Dies the radius get sharpened too?  

It's been so long since I used a draw knife I didn't remember which way the handles were bent. This makes perfect sense they'd make it much easier to pry the bark loose if necessary. IIRC most of my draw knives have different angles one almost flat but angled, sort of like handlebars. Some of the blades are really narrow, all are  more narrow than yours. I'm wondering if a couple of mine are draw shaves rather than draw knives. One has a blade maybe 3/4 wide, I'm thinking it's a shave, it didn't work very well barking or dressing logs. 

Do you use a barking spud? They rule on green logs and you get to stand straight and push with your hips. I love the smell barking green spruce, my clothes would carry the scent for days. I was living in the woods, the closest laundry was a ways so a smell other than me was a nice break. 

Frosty The Lucky.

[SLAG]

BMB  &  Frosty,

The barking draw knives, I used ages ago, and the two that I still own  all had wide blades than my regular draw knives

Also the tools were much heavier than the other knives

Does the extra width  and weight helps it to do an easier job.?

I always thought so.

Regards folks, and stay virus free,

SLAG.

 

[bigfootnampa]

I like most of the properties you describe.  I find that 10” or 12” edge length is good for such use and most general work too.  I also like a good sharp edge but for most drawknife work a clean bevel seems more important than a real shaving sharp edge.  I prefer to work with my bevels down but when I am doing bark peeling I often use it the other way... like you. I like to have a pear shaped handle or one that tapers thicker at the heel.  Textured rustic handles are nice!  I’ve rescued antique models by filling splits or cracks with epoxies or UV glues and some super glues.  They can be kind of interesting and very practical!  

[gmbobnick]

I suspect different kinds of bark might need slight modifications in design.  I am peeling very dry, lodgepole pine.  Sometimes I am just shaving grayed-wood and not even bark.

Weight is definitely a plus.  The tool is resting/sliding on the log for both push and pull, so the extra weight is not tiring.  Its kind of fun when you see a knot coming...as I try to glide through it without hesitation.  

I have never seen a beveled radius at the ends of a draw knife blade.  I guess I would need to create a ricasso of sorts there to carry a useful bevel around the radius.

[JHCC]

On a side note, the tightness of the bark to the wood can depend on when it was cut. For most species, cutting in winter = tight, harder-to-peel bark, and cutting in summer (i.e., while there's sap flowing in the cambium layer) = loose, easier-to-peel bark. As with everything, of course, there are exceptions.

[Frosty]

I've never barked a dry spruce log that wasn't a PITA, literally had to carve it off. Green and you can almost peal it by hand. My parents lived in N. Cal for a while amongst the Ponderosa and Lodgepole but I never tried pealing one. Not even by accident say  missing while splitting.

I have no idea how a barking spud would work on dry Lodgepole. 

Frosty The Lucky.

[bigfootnampa]

I have no experience with bark spuds... but I get the impression that they are most useful when the bark is being saved.  Bark siding has had occasional periods of popularity.  I recall reading about one bark dealer that had sent his minions to scour antique shops across the nation for serviceable bark spuds!  

[ThomasPowers]

Not to mention "tan bark" for veg tanning leather.

[gmbobnick]

I know some potters that fire their clay with various types of bark to produce different colors and effects on what they make.  One came and gathered up a bunch of pine, willow and elm bark around my firewood pile and seemed pleased.

[MilwaukeeJon]

Nice work on the draw knife. It is such a nimble tool. Blade up it can really rip the bark off of a log, while blade down it is possible to tear into a wood billet for removal and shaping or do incredibly fine surface work.

[Jefferson]

What would you charge for 2 of these? I have some about that size, but a friend wants two for his sons to peel logs with

 

thanks,

Jefferson

[gmbobnick]

What would you charge for 2 of these? 

I am flattered, but I suggest checking out Barr Quarton who has an on-line store and makes a far better tool than I could provide.

[George N. M.]

Glad to see another Wyomingite posting here.  My best friend lives just a few miles from you off of Burma Road and I was a geologist in Riverton in the late '70s and early '80s.  Once the covid madness is over if you are ever going to be down in Laramie let me know.

By hammer and hand all arts do stand."

[Frosty]

Welcome aboard Jefferson, glad to have you. If you put your general location in the header you'll have a chance to hook up with members within visiting distance. 

I'm not gigging you but this kind of question is best handled with a PM or in the Tailgating section, rather the open forum. 

Frosty the Lucky