23 December 2014

Layer on layer

Open post #5 dating back from September

A post about a technique that looked counterintuitive to me, repetitive layering.  Maybe it is more a finish carpenter technique.  Anyway it is nicely illustrated by Jon Peters with the build of a blanket chest.  He starts with a box and then ads a frame, feet, ... and ends with a detailed chest. Nice work. jonpeters.com









21 December 2014

Lure and lore of the framing square

Open post #4 dating back from September

Framing squares with their sides filled with tables and numbers are attractive.  Maybe because in my mind they share something with rune swords.  And that's of course my mistake,  I want magic and it's mainly about math.  To get the swords part right, swords are in medieval literature supposed to rely on relics not text:  E! Durendal, cum es bele e seintisme! En l'oriet punt asez i ad reliques:  La dent seint Perre e del sanc seint Basilie, E des chevels mun seignor seint Denise, Del vestement i ad seinte Marie. (Turold 1080)  That's the fantasy part, in real they probably relied only on a hard edge.  I can imagine that rune swords are just like framing squares mainly a 19th century invention.


Now OK, I did look at the framing square maths.  As I was curious enough I studied the tables and numbers.  It's interesting but it doesn't relate to anything I ever did.  Stairs for example are mostly made here with steps between the stringer,  not on top.  The advantage of seeing inches on the square as scaled down feet is also probably lost if I use a metric square.  So I have a book, but not the square.

When making structures with diagonals nowadays things have changed.  Compared to 40 years ago I now have calculators, excel sheets, tape measures of more than 2m and no need for a plumb bob. I would probably be better served with something like an alpha square to solve angled framing problems.  There is a good video about precise measurement cut with a chainsaw using a long tape measure and an alpha square.



Looking for framing square information on youtube I discovered Mark Harmon implementing a low math framing square for framing composed hip roofs: The adjustable hip square.  The square is made to set out 45° hip and valley rafters. To simplify calculations the frame scale is offset by a √2 factor so that the orthogonal values can be used when measuring diagonals.  And by keeping that scale and measures to the horizontal, the roof angle doesn't change the values either.  The only problem is that the measures are stepped,  giving most probably cumulative errors.  A specialized jiggery,  but it looks like an attractive low math solution for one type of problems.  


Of all that lure I acquired a Stanley adjustable quick square to serve as a sliding bevel. I offers me a locked angle together with its complementary angle (90°- angle).  It's jiggery, but I know I sometimes miss the complementary angle on a sliding bevel.  Now what about my next problem, the halved angle?  There is certainly a jig about that too.  Maybe all I needed was a good protractor.


14 December 2014

Wood pecking

Open post #3 from June

Walking in the woods in I saw that someone found a woodpecker in a tree and many other animals.



A little further I found a white-red GR marking (tree on the left) of a long-distance Grande RandonnĂ©e  footpath,  following that trail could have lead me over France through Spain. Compostella, Gibraltar, ....

But there are plenty of short distance alternatives too.  The number  on top allows to walk by numbers over a grid.  There is also a more global grid for cyclists.

Walking by numbers
Cycling by numbers

12 December 2014

Wooden planes - Japanese

A late seventh post in a series about western wooden planes

Thanks to the possibilities offered by ebay I unexpectedly added a Japanese plane to my collection.  The plane was described as 1940's Japanese Old Wood Plane Tool Carpentry. It was offered at a very good price and after a two month wait,  I finally got it home. No complaints about the quality,  no notable bedding problems, no cracks, the only special part is the blade geometry.  Where I expected to see flat surfaces,  I found a lot of curves.  First a secondary bevel just on the lamination,  making it difficult to see if it really is a laminated blade (it is) or a cheaper massive model.
But there was also a curved primary bevel. It will take a number of iterations to straighten the blade and to improve my sharpening technique.  A great help is the youtube series by Sumokun about Japanese planes,  and the faint memory of a Japanese carpentry session.

The not so flat bevels made me think about cupped sharpening stones.  That's not what I expect from todays Japanese blades, but fifty years ago thing could have been different.  Paul Sellers presented today a first post about past cupped sharpening stones.
The same could have been the case in Japan.  In a video 17th Generation Yoshimoto Bladesmith Murray Carter works fluently with a cupped natural stone and expresses his unwillingness to waste stone by just flattening it. He seems to favor controlled wear to get stones flat.

Back to the plane,  with three parts a wooden body and two blades it is a most simple plane.  Setting it up a new plane is probably less simple as every part needs a perfect fit.  The blade for example is wedge shaped in width and thickness.  An extra problem is the width of the blade,  it is certainly impressively wide but it makes everything more difficult to handle. It is a lot wider than my 5 cm stones (2") and also probably than most sharpening jigs.  So if bought  new I would have taken a narrow model. In the meantime I still need a few sharpening sessions to get the blade right and some patience to see how the plane sole stabilizes to the local humidity.

09 December 2014

Rali planes

Open post #2 also from January
Last week I saw a video of a German apprentice carriage-maker with a Rali plane (to be seen at 8:00) and I thought why would she do that.

So, I tried to see why.  According to some it is best to have an expensive quality plane as first plane, a way to know what it is all about from the beginning.  That is until you need to sharpen, as planes are mainly about sharpening.  Are Rali planes an alternative for beginners?
Price,  I found a factory price-list on the internet and suddenly the prices just look right.  We are talking 40€ for the standard model.
Setup, in a Rali demonstration video one can see the demonstrator  switching from thick to thin shavings in 2 seconds. Seeing Paul Sellers doing the same feat in 3 seconds with a #4 Stanley plane was impressive,  this is a near idiot proof alternative.
Sharpening,  Rali goes for replaceable blades.  The idea is not new but for a beginner this is perfect,  after messing up the first blade,  just reverse the blade and continue planing.  Even for a professional,  with the price of one edge set at 1€ (still that factory price-list)  there is little reason to go for a resharpable blade.  With the possibility of tungsten carbide blades, probably to plane plywood.


The factory pricelist is more a dream and it was probably dated,  what I can get are planes at 140€, HSS blades at 4€ and tungsten carbide steel blades at 24€.  Now,  4€ for a blade is 2€ for one side.  This is still a good offer if one considers the time and investment needed to sharpen. The only problem is that chisels also need that sharpening investment.  Rali is probably happy I mention chisels as they have also a solution with the shark chisels,  but ...
Apparently the insert bottom right is to hold a jigsaw blade,  center right are scrapers and their angled holder.

07 December 2014

Stanley mileage

December,  time to post a number of unpublished posts and eliminate the others.  #1 from January.
After I had questioned the unused,  pristine state of Zyliss vises in a post,  I thought it would be fair to also look at second hand Stanley planes.
Here the opinions diverge,  according to some second hand planes are often usable as such,  where others consider those planes only usable after a drastic overhaul.
For the planes I bought, the soles were definitely more flat than the old ironing irons I have. Looking at the plane irons I find them mostly long,  with much, maybe even all, sharpening length left.  Only the shortish #10 blades, starting with maybe 1" of usable blade, show worn blades.
So,  to make it scientific I did an ebay search and looked at the first 5 #10 planes. I did found 1 worn blade.  The four others give the impression that one or more ownerships are good for an average of maybe 1/2" of wear.




The end of life blade,  the blade is the small shadow at the bottom.  Seeing the iron poorly aligned I checked to see if there are different iron widths.  No just one width,  the #10 is similar to a #5 and the #10½ to a #4.

I once nearly bought a second hand wooden plane with iron sole and HSS blade, made for harder stuff like plastic. Upon searching I found a saved picture of it.  The blade was completely used and buying a new iron would have more than doubled the price. On the other hand maybe there were still years of use when using it on softer stuff like plywood and welding the blade back to length with an extension.  And maybe not on aesthetics,  but technically it is close to an infill plane.  Anyway this is mileage although most of it could come from abusive grinding.


30 November 2014

Knives: Bread knives

Where a large serrated knife is often considered part of a basic three knife set together with a parring knife and a chef knife, my bread knife is my number one as I cut bread daily and bake when needed.  For baking I just use a  automatic bread maker from Panasonic.  For cutting I never bought an electric food slicer and and as long as the kids are not complaining it will be done with a serrated knife.


My bread knives left to right: Stroma (English?),  Diogenes (Germany), Opinel (France) and Victorinox (Swiss)

Stroma:  Someone left this old thing and took mine away when I was a student. I imagine it is from the fifties.  A good thin blade, tapered both ways.  I finally resharpened it when I discovered that my chef's knife was doing a better job.  Upon control the serrations were the original poorly made factory serrations.

Diogenes:  I knew it with an aluminum body and designed in the fifties.  But here Herder und Sohn from Solingen (yet another Herder knife maker from Solingen) made a new run in the nineties.  It's good for slicing out of the hand,  finishing the cut is the most difficult part.
My father must be part of the last generation to have cut traditional round breads to the chest.  In dutch it is expressed as cutting to the breast.  Bruegel depicts(1565) a woman in blue cutting bread to the throat,  but I guess that's for clarity. He also shows a man cutting bread to the 'table'. As he had much of an encyclopedist maybe there was a gender specific approach.
And then probably not.  The thick short slices on the other hand are cut cut here the French way.

Opinel:  I was surprised to see their bread knife to be a wrongly serrated (left handed) knife.  So I bought it as I am left handed with  knife and saw.  Upon evaluation I agree with Opinel, wrong is right, although the difference is small. This because: - Depending of the side of the serrations the knife will more easily slip sideway on the crust when cutting uphill or downhill. With a wrong knife this will happen on the first slices when there are no consequences,  and much less on the last slices when my fingers are close. - The other problem with a single sided bevel is that it will cut (slightly) sideways. The wrong knife makes slices tinner at the bottom, but when slicing it is always easier to tilt the knife to a thicker bottom than the other way around.
The design is special for a serrated knife,  I imagine it makes cutting slices longer than the knife possible,  but it is hard on the cutting board.  I also found the same design (Herder Abr. & Sohn Solingen) on ebay but with larger serrations described as a sausage knife.

Victorinox: It is a recent acquisition, I wanted a blade longer than the 20 cm (8") standard. I would call this model a pastry knife and they have a more bread-worthy knife,  but this one had the bestprice . The green handle kept it under the price of a cheap, four amazon stars, electric food slicer (the table saw model, not the twin blade thing).  On Amazon that day: with a red handle +50%, black handle +70%,  wooden handle +250% and the real Victorinox bread knife +100%.  It is also a thin double tapered blade. The 25 cm blade is more fun,  I should have tried their 30 or 35 cm model,  'maybe' I could get a 15 cm (6") thick slice in just one back and forth cut.

When controlling the sharpening angle I was surprised to see a 20° single sided factory serration on the Victorinox and an even lesser 15° single sided serration on the Opinel. Half of the more standard 20-15 ° per side of most kitchen knives. As a reference, Robert Herder parring knives (from Solingen) are sold with the notice to not use their thin blades on bones and bread crust.  Visual control shows no damage on the Opinel and a few damaged spots,  not necessarily the serration tips, on the Victorinox.

The last five years I did cut maybe 1000 breads, but cutting with a bread knife is not always easy. There is room for variation,  most of the time I cut thicker in the back and the slice gets thicker at the bottom.  The quality of the bread is important, where bread from a baker is never a problem, fresh bread or poor dough influence the cut more than any knife. Although, I once tried a poorly made Ikea knife, no, that one was not good.  The top image shows the result of a few unfocused cuts on a fresh bread, where is square? Why do I still use hand tools when electricity offers more consistency?

[edit] The rest of the week the results were acceptable, even on fresh bread, so that's probably why.

20 November 2014

Knives: Cuts and sharpness

Some time ago I got interested in improving my kitchen cutting technique,  mainly cutting-board cutting.  So I looked what youtube had to offer.  Cutting an onion on youtube is nearly a standard but there is not much variation on it. Or rather any demonstration not perfectly meeting the standard will massively be downvoted by professionals and youtube specialists alike unless it concerns a Japanese suchi champion.

The cuts.  Knife cuts get really interesting when spooncarving and such high risk activities with its numerous variations.  When cutting to the board I see three main movements:  1. The push-cut straight down to the board, that's also chopping.  2.  Slicing,  moving the knife moves mainly forward from tip to heel or vice-versa. There is also repetitive-slicing (sawing) as a variation on slicing, I use it when cutting large peaces of meat or bread or with a blunt knife. 3. The skewed cut,  when the tip rests on the board and the knife is pulled backward.
Important is that a knife may be too blunt for a push cut and be perfectly fine with slicing and skewed cuts.

Cutting and sharpness.  A sharp knife is a safe knife and all that.  But things are not that simple.  This picture from a video by Virtuovice shows a razor sharp knife doing a push-cut through an apple.  I don't think the sharpness of the blade is of any help, a completely blunt but narrow knife would cut better and straighter. For Virtuovice it's probably not a problem as he uses his knives to cut meat.  When peeling the apple,  still a push-cut, the sharp edge can be used as the thin peel can be pushed away. But here again a thin, narrow bladed parring knife will be in line with the cut and need less effort.
When parring I look for a balance in sharpness.  If the blade is too sharp I will cut my fingers who are holding the apple,  too blunt and I will need to saw cut to peel.  So I need a Goldilocks blade able to push cut the apple,  but not my fingers.  When cutting to the board,  my fingers are less at risk. I then can go for a sharper blade or I can use the more effective slicing and skewed cuts.

Cutting an onion  After trying out the big (chef's) knife approach,  I came back to using a paring knife to cut vegetables on the cutting board. And that's what most people I know do.  I go for a medium sharpness,  sharper than many households here but less than many professionals and certainly less than some sushi knives.

A sharpish thin bladed parring knife can cut onions like butter and gives a good result,  a chef's knife is not  necessarily better or easier. The cut used is a folded cut: from the tip slicing until nearly touching the board coming back with a skewed cut. And maybe there are less tears when the open onion surface is minimal.

As a matter of fact the same cutting technique with a ten year old factory edge (that's blunt) table knife is no fun,  but still offers acceptable results.
An ever harp knife
I sometimes hear people claim to never sharpen their parring knife.  Mostly it concerns the (razor) thin carbon version of the parring knife I use with an edge of maybe 5 degrees per side.
Looking at Cliff Stamp post about edge retention at lower angles, one can see a confirmation of that as their is a clear distinction between 25 dps and 13 dps.  13 dps cuts on and on,  only slowly achieving a too blunt state, where the edge of 25 dps dissapears fast to an unusable state
.


17 October 2014

Knives: Sharpening angles

Personally I am an angle extremist as my main (vegetable) kitchen knife has a micro bevel of 14° (or 7 degrees per side).  Great but this time I wanted to sharpen a camping knife,  so which angle to choose?

Googling for data I get the following.  Looks good  ...  although 35° that's not much for a cleaver ... are machete in the same category as cleavers ... then I got it, these are sharpening angles, so the edges start at 24° to go up to 70° ...??? ... Welcome to the 21st century!

Second attempt and back to last century,  I took The complete guide to sharpening by Leonard Lee (1995).  I found a rather pragmatic approach:  for kitchen knives anything between 10° (5 dps) to 35° where the major aspect is finding an angle that is easy to reproduce when sharpening.
For camping knives he proposes 30° when whittling and 15° when mainly handling meat. I am not sure I agree there as I expect that when cutting meat from bones there is more strain on the edge. And a blade that doesn't 'bite' the bone too easily is more comfortable.

Looking at factory angles
Morakniv  knives do talk about angles, they are not in microbevels and propose 23° (12 dps) and 27° (14 dps) for their heavier 3.2mm (1/8") thick bushcraft knives that need to withstand batoning.  It is surprising they go to the American bushcraft market with anything thinner than 1/4". They are probably more hard headed traditionalists than marketeers.
Opinel knives, I couldn't find anything on their site.  Someone talked about 25° as recommended by them,  a sharpening angle so that's 25 dps.  It sounded so ... 21st century that I checked.  It's true, the picture shows the main reflection from the convex blade, but at 25° there is the reflection of the micro bevel.
For the old Opinel blades I can't see the factory edge anymore, but remembering the ease at wich they dented I guess 10° (5dps),  the blades were not yet convex then.

Now why do I think 50° (25 dps) is excessive.  When looking at plane blades I see angles of  25-35° used with the blade off center, that is not in cut but rather a scraping movement and regularly slammed with great force (6# of plane and the guy behind pushing with his two hands) against knots that represent a localized high resistance point. Apart from chopping bones there are few situations worse than that.

On youtube I found Canadian Cliff Stamp talking about Edge retention as a function of micro-bevel angle
and offering new perspectives on optimal angles.  He's someone who seem to spend his free time sharpening and cutting truckloads of wood, cardboard, rope and old carpets to assess his sharpening. This delivers interesting work and results.
What he says is that edge retention increases with smaller angles up to some usage-user dependent tipping point. On the graphic 13 dps does 4 times better than 25 dps.  I guess that the graphic stops at 13 dps because he uses a Wicked Edge sharpening gig to set precise angles. Thus losing the ability to go for low angles, the jig being a 21st century product and all that. The Wicked Edge minimum of 13 dps is a lot more than the Leonard Lee lower limit of 5 dps.
The reason behind the improvement are twofold:  low angles cut with less strain so less wear and they offer more 'meat' before the edge becomes too blunt.

So the micro bevel for the camping knife? Whatever I want,  maybe 30° (15 dps) to follow Leonard Lee, probably less.