giovedì 7 febbraio 2019

Pasi Hurttila maasepän puukko

Pasi Hurttila
is a wilderness guide and part time blacksmith living and working in Ivalo, 260 km above the Arctic Circle in Finnish Lapland.
Pupil of Martti Malinen he has been a full time blacksmith from 2007 to 2015; nowadays he has resumed doing mostly guiding, keeping forging for the moments of inspiration.


blade
length - 87 mm
wideness - 21 mm
thickness - 3 mm at the spine, 4,4 mm at bevels junction
steel - ThyssenKrupp 80CrV2
grind - flat
edge angle - 20,5°, tiny microbevel
edge hardness - ~ 62 HRC

handle
length - 110 mm
wideness - 30 mm max.
thickness - 22 mm max.

weight
knife - 85 g
with sheath - 130 g


The blade was forged with hand held hammer from a bar of 80CrV2. It has a rhombic section, slightly tapered in height and thickness. All the heat treatment was done with the charcoal forge. After annealing and normalization the blade was heated in the fire, quenched in oil and tempered twice on the coals. During the quench the spine and tang were kept out of the oil to remain softer. The bevels are grinded to 20,5° with just a tiny hint of microbevel.

The handle is crafted from a piece of birch burl. The tang is glued with epoxy and has two little wedges at its sides to make everything the tightest possible. It’s sanded to a medium grit, giving the handle a smooth but grippy feel. Slightly tapered in height and thickness on both sides, it has a subtle teardrop section. Its slightly oversized proportions fills very well the hand.

The sheath is hand stitched from 2,5 mm thick leather. Inside there is a two sided birch liner, carved with puukko and chisel, then sanded on belt sander. The belt loop is a simple leather strip. The retention is excellent, though not much force is required to unsheath the knife.








In use

As frequent in Hurttila’s style the knife is slightly oversized compared to the average, especially in height, having thus larger proportions. However the combination of the bigger proportions of the handle with a not too thick blade make the puukko feel lighter than its actual weight and balance it perfectly neutral.

Before starting the tests I stropped with Bark River green compound (#6000).
As usual I started with the six months seasoned plane wood spikkentrolls.


The puukko had the best combination so far of bite, nimbleness and cleanness of the cuts. Nothing to signal during the carving of the first troll. I felt only a little resistance when carving against the grain to create the hollow of the second hat. As with all the others I planed two knots as well.
At the end of the work the edge was pristine, with just a little loss of shaving bite in first cms closest to the handle. Four passes per side with green compound.




I then continued with the three months seasoned poplar wood wizard.


There was a mild resistance when, cutting the two facets, I went against the grain. No problems whatsoever during all the rest of the carving, the puukko just confirmed its fastness and cleanness of work. A couple of times, when doing small adjustments on the facets apex, pulling the puukko towards me and using the thumb as fulcrum, I felt the handle just a hair large, but the sensation cased modifying slightly the grip. The tip, the only tapered one so far, was not surprisingly the best to engrave the nose profile and working on the lower lip.
Having used this puukko right after Tikkanen’s one, which is considerably smaller and has a slightly more obtuse edge, I had to recalibrate to adjust my hand to the larger handle and more acute edge, especially concerning the force to be applied when cutting.
At the end of the work the edge was pristine and the shaving bite unchanged. Five passes with green compound.




I then closed with the usual one year seasoned silver fir spatula.




The lower thickness, compared to Tikkanen's puukko, as I was expecting, exasperated the gliding-in-the-fibers capacity of the knife. As same as with Tikkanen puukko, the only resistance came when I was roughing the front of the spatula, cutting tangentially to the fibers. Nothing to signal until I had to deal with the knot. As already did with Tikkanen’s puukko I planed the knot from the sides and from above, from both sides of the spatula. The heavier Tikkanen’s blade allowed me more power and a faster material wasting; this knot took me longer since I worked it from both ends and also due to some remaining resin that made it sticky enough to force me to waste it one chip at a time. Having finished with the knot I didn’t felt a loss of bite and the cuts kept being clean and glossy. Nothing to signal during the working of the shaft junction and all the finishing cuts. Once thinned down the front part of spatula cutting tangentially to the grain wasn’t a problem anymore. During all the work the handle was very comfortable and nimble. The blade kept an excellent bite, alternating well enough power and preciseness. The shallow curve of the edge was very effective in working the concave surface of the shaft junction, pulling the puukko towards me. Generally speaking it left the cleanest surfaces and cuts.
At the end the edge was pristine and still shaving without pressure.



Conclusions

A rightful praise goes to the combination of heat treatment and geometry. It wasn’t granted, given the angle and hardness, for the edge to stand so well the knot wasting. It could have brought the steel resilience to its limits in this combination of geometry and hardness and, even though I never had problems carving seasoned wood also with a puukko in 80CrV2 at 62 HRC, but with a 19° edge, wasting a knot like this can be hard on puukkos anyway. Being slightly oversized hasn’t prevented the puukko from being light and nimble, as I’ve already said. My preferences for the handles of this type combined with the puukko excellent cutting performances, made it particularly easy and relaxing to work with.

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