Monday, February 9, 2009

Utility Knife Step-by-step: Part 1

Ok, it's been a long time coming but I've finally managed to get some work done in the shed and will now attempt to explain how I make a knife.
I've actually been a little sceptical about doing this post because it really is a 'warts and all' insight into how I put a knife together. It shows the mistakes I make as I'm learning this craft and the efforts I put into correcting those mistakes.
If for example, I manage to bust one of the scales as I'm grinding the handle, I'm more inclined to try to repair it than start again.
It's a learning curve for me and I'll know not to do whatever I did wrong next time around.
The way I see it is this: These are knives I make for myself and for my close friends and family. If you give someone something you've spent countless hours producing, it's unlikely they'll nitpick about an imperfection.

I'll warn you now, this is a long post and some of the pics were rushed so please forgive my photography this time around.

Everything I've made so far has been done using the stock removal method. This involves taking a piece of steel, cutting a knife 'blank' out of the material (I use an angle grinder with a cutting wheel), and then shaping the steel using whatever means one has available before finally adding a handle and finishing the knife.
There are other steps involved in this process and I'll try to detail them as I go.

I've already cut out the blank, as per my last post and need to continue grinding the steel to refine the profile and overall shape of the knife.
What I didn't mention in my last post is that with some of the steel I use I need to anneal it before working on it - in some cases before even cutting out the blanks. The pieces I'm working on now are all from a piece of HRPO which is tough as anything so I gave it a quick run over with the MAPP torch right after I scribed the blank patterns into it - I did this so it wouldn't rip through my cutting wheels, and even then I was still using on average one wheel per blank.
I then gave the blank another pass with the torch after it had been cut out, bringing it up to cherry red and then letting it cool slowly before beginning the grinding process.

I don't have pictures of this in progress but I used a multi-tool linishing attachment on my bench grinder to grind the profile into the blade. I've basically moved the blank from the ricasso to the tip on each side of the blade horizontal to the belt until I'm happy with the amount of material that has been removed.
After doing this, I've draw filed the blade so I can have more control over the shaping.
I haven't draw filed before making this blade but I'm pleased that I did because previously I feel I've overdone it with grinding and haven't ended up with the type of finish I was after. I found it's also a lot easier for me to put a ricasso on the blade using a file rather than the belt.

After shaping the blade I've drilled holes for the pins. I'm trying a few different things this time around. It's a full tang knife so I really want to make sure the handles hold strong so I'm putting in 4 small pins and two larger ones.

Because I'm a dolt and never bother to properly measure anything I have 4 extra holes that I won't be using - but they'll be covered by the handle and will give a little room for extra glue.

In the spirit of self discovery and learning I decided I'd have a go at making some mosaic pins. I'm not going to go in to detail on how this was done in this post but I learned how to do it and here.

The gist of it is: insert a few bits of wire into a larger diameter tube with glue and allow to set before sticking in a knife handle.

I've also done a little filework on the spine of the tang, following a tutorial I found here.

For the next part I've put one of the handle scales in the vice and drilled holes for the larger pins and the lanyard hole. I've then used the pins to hold the knife in place on top of the scales so I can drill the 4 smaller holes.

After the holes are drilled swap out the scale for the undrilled scale, replace the knife and the pins (though now they're the other way around) and drill through the existing holes so they're mirrored in the other scale (I hope that made sense).

With all the holes drilled I'm now ready to assemble the handle and glue everything up. For additional places for the glue to run I've drilled a few indentations between the pin holes on the inside of the scales.

Before I assemble the handle I heat treat the blade - this deserves a more detailed description so I'm saving this for another post.

Before I glue anything I make sure all the pin holes line up so I don't work out something has gone wrong as I'm gluing everything together.
I apply epoxy to the insides of the handles, to the tang, and press it into each pin hole before inserting the pins and clamping everything in place.
I added a little black ink to the epoxy - explanation for this will come later.

I'll post part 2 in a few days.