Wednesday, 15 June 2016

New knives and new designs WIP - Canadian Belt Knife ( 3/?)

Times are busy, but there's still always time for knife making! The scales and knives have been glued together and I've completed the first knife of the batch. There isn't too much that I have done differently from previous knives, so I'll let the pictures speak for themselves - enjoy! 

Front of  scale shaped for gluing. From left to right - black canvas micarta, African blackwood, chatke viga, osage orange, natural canvas / black paper micarta.

Attaching scales
The first knife that I completed was the Canadian belt knife that a colleague of mine requested for a fathers day present. Below are some shots documenting the process.

Handle shaping on the 2x72" grinder. The wood is osage orange 

Finishing and sealing scales.

Starting the sheath - this is the first one piece sheath that I've done. 

Stitching the belt loop - extra care needs to be taken in sinking the stitching into the leather prevent the knife from cutting the thread.

Attaching the welt - in this case the welt needed to be built up near the handle to accommodate the handle thickness.

Alignment with finishing nails prior to gluing and stitching.

The whole package done! 

Backside of the completed sheath  sealed with leather conditioner and hot wax.

Sunday, 1 May 2016

New knives and new designs WIP - more lessons learned ( 2/?)

Hi all,

It's been a bit of a gap due to waiting for some handle materials to come in the mail, but I'm happy to say that I've been able to get back to work on them!

I heat treated the blades after normalizing them three times at critical temperature ( dull cherry red, or about 1500 degrees F~ as close as I could judge by eye), soaking them at temperature for 10 minutes per cycle before finally quenched them in warm vegetable oil in the last cycle. The warming is critical to prevent a vapor jacket from inhibiting hardening and maximize the transfer of heat from the steel to the oil. They were then immediately tempered in a toaster oven for 2 hours at 400 degrees and allowed to cool to room temperature.

Normalizing on kaowool ( the second puuko from the right has a slightly shorter bevel from the other one - I accidentally set up my guide too far forward on the blade but it's an easy fix) 

Quenching in vegetable oil

Post tempering shot - still coated in scale.

Descaling in citric acid bath
While fixing some minor warping in the knives that happened during heat treatment, one of the Canadian belt knives to my horror had snapped in half at the junction between the blade and handle after some minor bending in the vise. This was initially quite shocking as I thought I had done everything right with the heat treat with what equipment I had, but it just goes to show that you can always learn something new. Having a closer look at grain showed that it was extremely fine where it had broke, so taking the knives back to the forge wasn't necessary.

A chunk of the broken blade - I would say that's fine grained if I ever saw it and ideal, just too brittle though. 

Back tracking, I figured that it would be worth testing if the tempering was too low to take the brittleness out of the steel.  I put the knives and broken blade back in for a second tempering cycle for another two hours at 450 degrees to see what difference it would make and do some impromptu destructive testing to decide if the batch was a write off.

Following tempering, it was back to the vise, and thankfully the higher temperature was a success! I wasn't able to break the broken half of the blade using the three point method in the vise ( two pieces of wood on one jaw vise and one on the opposite jaw between the two oppose pieces). This resulted in the blade flexing to about 45 degrees from true after closing the vise as far as the wood blocks would allow and springing back to a slight bend that was easily corrected by bending in the opposite direction.

Success! This was after the vise had maxed out on tightening and the blade popped out along with the wooden blocks I was using, you can see how much they indented the wood jaws.

 Full disclosure, I didn't take any pictures during destructive testing for fear of the blade snapping catastrophically or popping out of the vise and destroying my camera - which was thankfully a good idea since the latter did happened and took out a chunk of my wooden vise jaws with it.  To get a failure I had to take the blade to my steel jawed vise and bend them to about 80 - 90 degrees from true - with plenty of bending before it snapped.  This is by no means a go ahead to use the knives as a pry-bar, but they will be plenty tough for normal cutting use.  I am by no means an engineer, but I would think that this is a good result and will be using this heat treatment regime from here on out! I'll be making a replacement for the Canadian that was destroyed in this batch in my next round of knives.

After receiving my handle materials in the mail ( liners and stainless thong tubes) , I went to work on the handle scales from African blackwood, chatke viga, osage orange, as well as natural and black canvas micarta in combination with black paper micarta and vulcanized fiber. There wasn't too much different that I did from the previous batch of knives aside from using a downdraft table this time around to keep dust to a minimum while getting them square and even thickness. One of these days I'll invest in a proper bandsaw to save time and headache when re-sawing wood, but until then it'll be the old school method with a jack plane, sandpaper on a marble tile, and Japanese ryoba saw. Again, not too many pictures of the action since I only have two hands.
Osage orange (top) and chatke via scales (bottom). Both woods are known to be extremely durable and have been used as fence posts where they are native, with reports of them lasting up to 100 years in soil.  While not at the level of rosewood, they also have a fairly high Janka hardness so they won't get banged up or dented too easily. For reference, maple has a Janka hardness rating of about 1400, while these woods have a rating of approximately 2300 ). Not pictured were African blackwood scales, which is one of the hardest wood species in the world -it was a bear to saw but I have a strong feeling they will finish beautifully. 
Keying the surface of liner materials for epoxy, in this case black paper micarta. A tungsten carbide file is a great substitute for low grit sandpaper and I feel it does a better job at roughing up a surface. It was also lasts MUCH longer and the handle helps reduce strain on the fingers and hands. 
At this point in time they're all epoxied up and will be ready for processing the next time I work on them - stay tuned!

All clamped up, and now we wait!  

Monday, 21 March 2016

New knives and new designs WIP ( 1/?)

Hi all,

Spring is in the air and I'm making the most of what time I can get in the shop! These will be my first offerings through my site and are designs that I've been wanting to do for quite some time. Not too much different from other knife WIP's that I've posted , with the exception being that these were all done with my new grinder and I've been experimenting with some different grinds. The designs that I chose to make this time around were a puukko , Canadian belt  knife, and a different take on the city knives I've worked on in the past ( doesn't need too much explanation).

The puukko is a very utilitarian design from Scandinavia that uses a zero edge bevel, which essentially means that there is no secondary bevel resulting in a very keen edge well suited for wood carving tasks and easy sharpening. The only tradeoff is that the edge is more fragile than other grinds with a secondary bevel or convex grind, and has reduced slicing ability in tasks such as food preparation.

The Canadian belt knife is a relatively recent design created by Rudolph Grohmann for D.H. Russell Knives originally based in Toronto in the 1950's and one of the few designs that originated in Canada. I was attracted to this design due to it's unique look designed for ergonomics. Its offset handle allows for a positive grip that prevents slippage forward and a substantial belly for hunting tasks. My take on this design has a much beefier handle than those currently produced by Grohmann knives to allow to fill the hand better and to make it proportional to the larger blade (5") to allow for some heavier uses such as light wood prep.

I'll let the pictures do the talking, but this batch has been quite fun in taking advantage of the capabilities of a proper 2x72 grinder - and I hope to get more batches done in the future!

Laying out profiles on 1/8" O1 barstock

Rough profiling with a hacksaw ( and drill press in tight areas) 

Center punching drilling locations

 Cleaning up profiles using an 80 grit belt.

Temporary angle guide for scandi edges - this one is made of pine but I'll be making a more permanent one in the future - probably out of aluminum or steel.

First scandi grind - success! 

Family photo after initial grinds. From left to right - puukko, Canadian belt knife, and gentleman's knife. The Canadian belt knives have not been finished grinding as I planned to make them convex for optimal strength and cutting performance.

Canadian belt knives after slack belt grinding to blend the half height grind and hand finishing . I used sand paper on a foam rubber backing to blend any remaining flats . Unfortunately I forgot to take pictures of this process as I only have two hands- but it was quite an interesting learning experience. I'll be doing more experimentation with convex grinds but I can definitely see myself doing more of them for heavier use knives.

The next steps will be heat treatment and building the handles, then making the sheathes.  I'm still in the process of deciding which materials to use, but will likely be using a combination of micarta and durable hardwoods like osage or African blackwood, we'll find out later.

Stay tuned for more!

Wednesday, 30 December 2015

Christmas Break Project: Hultafors Axe Sheath

As promised - part two of my Christmas project!

This would be my first attempt at a sheath for an axe still in production - so hopefully it will allow me to work on future projects with this model.

The process I used was similar to the axes that I have done in the past. The leather used is 7-8oz vegetable tanned leather, saddle stitched, and reinforced with double capped rivets at high stress points on the corners of the welt.  The only difference between this sheath and the ones the previously is that I used line 20 size rivets as opposed to 24 for the horizontal flap to be in line with the size of the sheath.

Transferring my CAD template to leather

Adding my makers mark

All dyed and ready to punch and glue.

Saddle stitching

And now for the finished product: 

Hopefully Chris the sheath is to your liking, it will be making its way back to you soon!

On a side note I have also made a pair of stainless steel firesteels that will be available on my website - a bit of an experiment between a larger handle and very compact handle.  Get em while they're hot!