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2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:41 pm
by kwakster
Recently acquired these two fixed blades made by Swedish manufacturer Pontus Holmberg.
According to this website the model was once used as a survival knife for the Swedish Air Force: http://www.gotavapen.se/gota/artiklar/k ... rvival.htm

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I'm in the process of giving each one a bit of TLC, and will post some pics later on.

Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:42 pm
by kwakster
Blade hand reground to it's original full convex blade shape on a Foss 7205 black/green silicon carbide stone used with oil, then refined on 400 grit and 1000 grit SiC wet & dry paper used with oil on glass, and the tiny burr stropped off on hard cardboard with 1.0 micron diamond paste.
The new apex measures between 20 and 22,5 degrees inclusive.
Very hard (guesstimate 64-65 HRC) and also very wear resistant steel.
Handle reassembled, now with all washers glued and pommel repolished, then treated to a few coats of warm Granger's wax.
Sheath waxed and hand restitched.

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:42 pm
by kwakster
The second knife is a bit worse, also due to the handle's leather midsection which had rotted over time together with a pommel stuck in place.

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:43 pm
by kwakster
Currently busy with making a new leather midsection for the handle of knife # 2:

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:43 pm
by kwakster
The new leather midsection after rough machine sanding with a cheap Parkside linisher (which i modified so it can do slack belt sanding):

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:44 pm
by kwakster
Busy fine sanding the handle surface:

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:44 pm
by kwakster
The blade has been hand reground on the Foss 7205 combination stone (burr is partly visible), and a few refining steps on wet & dry SiC paper will follow later.
Now regrinding the swedge with 300 and 600 grit diamond files.

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:45 pm
by kwakster
Regrinding the old jimping / notching using a cordless drill with diamond bit & WD40 oil:

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:46 pm
by kwakster
How the blade looks after hand regrinding to full convex again on the green silicon carbide side of the Foss combination stone used with WD40 oil.
The new edge angle measures ~20 degrees inclusive.

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:47 pm
by kwakster
Currently experimenting a bit with different grits of diamond paste on thin cardboard to see what gives both a nice blade finish as well as a good apex.

Already found that only removing the burr is not enough to get the sharpest of edges on this steel, i have to continue stropping a bit to also get the (presumed tungsten) carbides into the right shape.
I also have to tinker some more with the appearance of the blade finish (now it's a bit too shiny for my taste), but the current apex is reverse hairwhittling sharp (chest hair) @ ~20 degrees inclusive.

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:47 pm
by kwakster
While busy with finetuning the handle the knife slipped out of my rubber coated vise and fell from a measured hight of 1.10 meter on one of the concrete sidewalk tiles which form the floor on my balcony, and landed on the belly part of the edge.
I did not try to catch the falling knife :-)

To my surprise there was only slight denting in that area, no large chips, which i would have expected given the presumed high hardness in combination with the narrow edge angle.
Anyway, due to this i had to regrind the blade again on the green silicon carbide side of my Foss 7205 stone, and that is where i am now.

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Re: 2 Swedish Air Force survival knives

Posted: Mon Mar 18, 2024 8:48 pm
by kwakster
The result:

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Re: 2 Swedish Air Force survival knives

Posted: Wed Mar 20, 2024 7:07 pm
by SurfEasy
Geweldig beste @kwakster knap werk, en wat heb je een geduld en vakmanschap. :D

Re: 2 Swedish Air Force survival knives

Posted: Thu Mar 21, 2024 7:01 pm
by Peerke
Daar moet een vreselijke berg tijd en werk ingezeten hebben. Het is wel leuk om te doen als je er de spullen voor hebt.

Re: 2 Swedish Air Force survival knives

Posted: Sat Mar 23, 2024 10:28 am
by SurfEasy
Peerke wrote: Thu Mar 21, 2024 7:01 pm Daar moet een vreselijke berg tijd en werk ingezeten hebben. Het is wel leuk om te doen als je er de spullen voor hebt.
Ja @peerke echt geweldig dat zo voor elkaar te krijgen, een dikke pluim voor @Kwakster :D
Ook dat hij het met ons deelt een verrijking van het forum.