NOTE: 3/7/2018: Photos not visible due to PhotoBucket change in hosting policy - Although clicking in the gaps will displays the images in PB ... 12/8/19 Update: Photos visible again
Well I had a GAW recently for which I took a picture of the prizes, a couple of 58mm SAKs.
I displayed all the tools for the piccie, and absent mindedly left them like that overnight. You know what is coming next don’t you.
I folded the tools away the next day and the combi tool seemed to be sitting a little proud of the scales.
I looked inside and yep a broken spring
- Everyone here says never leave SAK springs in tension as it can damage them.
Well now I know it’s true
BTW - Sorry for the crappy photos – Many of them were taken at night in my poorly lit garage!
So I decided to have a go at replacing the spring.
- And thought I would document the process for a thread
Apart from hacking a 58mm to bits (see below), scale changes, and removing and replacing one Wenger 85mm pin just for fun - This was my first mod - So please bear with me
First job is to remove the scales.
It’s a good idea to put the scales in hot (not boiling) water just to soften them up a little and make prizing them off a little easier, and damage to the bushing housings less likely.
Take out the tweezers and toothpick and push the point of a thin knife into the hole and under the scales (a 58mm blade is ideal). Then slide the knife up to the two rivets and just rotate the blade clockwise. One end of the handle should pop off the rivets. Move the knife past the rivets and slide up to the next set of rivets and twist again.
Note: This shot is from a different knife.
You can see that a tiny shred of scale was sliced off in the last photo - I did not use hot water this time - So hot water may have prevented the damage.
If the bushing hole is damaged - You can still get the scales back on by putting a tiny dot of glue in the damaged hole when re-assembling
Swiss Army knives are held together with brass pins with 'peened' ends - and 'bushings' - Peening is described later in this thread - Bushings are very small washer like brass rings that have a dual purpose of holding the 'peened' end of the brass pin - this is what holds the knife together. They also have a small rim that holds on the scales. Conserving the bushings for re-use when you drill out the pins, is one of the big challenges of SAK modding - particlularly on the 58mm SAKs.
Here is my set of tools.
The peening hammer is 4oz and turned out to be way too big. I used a 2oz hammer for the peening – It was fine for the punch of course.
My most used tool is not in this pic I will show it at the end!! And also provide an equipment list.
I used duct tape to hold the tool down so it would not move when I was drilling.
You need to punch a small hole to guide the drill – As you can see I did not get this dead centre, which meant I ended up damaging the bushing, which had to be discarded.
It is at this point I will say this whole job is straightforward enough - but made very difficult
by the size of the tool
Everything is so tiny
it is quite hard to work with, or even see.
Drilling out the correct amount of material (with a hand held power drill) I found to be very, very difficult, as everything is so tiny.
There was a constant cycle of drill/check, drill/check, drill check etc. I did not want to use pliers to pull off the bushing for fear of damaging it, eventually I got it off.
The pin was a little messy so I used a file to file off the rough bits.
I did use pliers on the second pin and bushing I removed - and of course damaged the rim - So don’t do that.
I did not have a punch of the right size to punch out the pin, but found this screw worked fine!!
As you can see the pin did not come out all the way, so I did not lose the good bushing on the floor
I was hoping (but not expecting) that I could get away with just removing one pin to release the spring.
But not so - The other end is held in place with tool – So both pins need to be removed. You can see the broken spring here.
One thing I learnt at this point was that the combi tool (or any tools) move completely freely once the springs are released. I always thought that the peening gripped the tools and provided some tension – But not so – It is only the springs that do that. The pins just hold the knife together, and prevent lateral movement.
- This was good to realise – as I was always worried about getting the peening done just right later.
Here is a picture from another knife of what a 58mm knife looks like with one liner and the tools removed.
It is a fabulous and clever design (although not quite the same as the original patent!! – check out SAKWIKI
The springs are all identical, even the keyring spring is the same internally - as you can see - It just has the key ring loop as an addition on the end.
The thin tools (blade/nailfile etc) have a spring each, the thick tools (scissors/combi) use two springs. And tools on opposite sides to each other always open at opposite ends. The small teeth interlock, I guess for stability, when the tools are in place.
I took this one apart early in my days of SAKness and am ashamed to say I just hacked off the pins/bushings, with a hacksaw or file (I did not know how SAKs were held together or even what a bushing was
You need 1.5mm brass rod (available from a model shop), from which you cut an appropriate length - Mine are probably too long - But don't make them too short as this is diffficult to work with.
So now you have to peen the bottom end - Peening is the process of tapping the end of the brass pin (normally with a peening hammer) so that a small rim forms, that then secures the pin in a bushing - Or slots up against the scales in an alox knife. For the thin pins used in a 58mm Vic this is a very delicate task
Make sure you file the cut end of the pin rod to a nice smooth surface to ensure good peening.
There are theories around about holding the pin in a rotating drill bit, to ensure even peening (I did not try the rotating action) etc. My first two attempts completely bent the pin.
I ended up just putting it in a modeller’s vice, with a tiny amount exposed, and using the 2oz peening hammer.
I found the best technique was to tap the edge of the pin at 45° or so - very gently, with the round end of the hammer, and going round and round - to start the edge to fold over.
Once the edge had formed you could tap a little harder and all over
I noticed on the pins I removed, that the peened end of a pin was more of a Y than T shape – So used this technique to help fill out the bushing:
I put the bushing and then the combi tool on the pin, then put the pin in the vice, with the pin exposed by a tiny amount. I could then tap the pin down into the bushing, so that the bushing ‘cup’ filled up nicely.
Threading the first pin was easy peasy. I wrapped some tape around the first pin to make sure it did not fall out (and loose a bushing those things are tiny). But don’t do it like in this photo
– The tool must be taped up in the fully open position, so you have free access to the open end of the springs.
I tried at first to thread the second pin just holding the knife in my hand – I could not do it. Not enough hands, the spring tension was too much and the pin would not thread.
So found this method worked.
- File the threading end of the pin into a nice smooth point (see pic) – It did not work with the roughly crimped end
- Hold the SAK horizontally in your vice with the vice holding the fully intact bottom two pins/bushings sets (the top two pins in the photo above)
- I used the blunt end of a drill bit held in a clamping wrench to push the springs down with one hand, whilst I pushed in the pin with my other hand. - I used the drill bit as I could select a piece of metal exactly the right size to slot between the liners and push the two springs down together.
If I was doing this regularly I would make a little wooden or plastic pushing tool!
Sorry no pic of this stage in the vice.
Note: You can see in this pic how nicely the earlier peening worked on the other end
Once the final pin is threaded you can test the tools (don’t need a peened knife to do that) everything snapped perfectly – I cannot tell you what a great feeling that was
I read that you need about a liners thickness of pin to make the top peen – So I put two liners on – I did not want to risk being too short (after all that work) - and figured that if there was a bit too much I could always file it down.
Peening a knife that will have cellidor scales is much easier than doing an alox – Your peening does not need to be absolutely perfect as:
- You have a nice bushing the work the pin into
- Your peening is hidden under the scales
Hmmm - My pliers did not cut right up to the edge – So ended up with this, I think I did file a bit off the right hand pin and of course both pins need to be nice and smooth to start the peening.
Note the spare liner is still on top of the bushings here
And here we go all nicely peened up.
And now with the scales back on.
No need to warm up the scales this time, as the bevel is going the right way to push the scales on (and also water could get trapped in the pin pockets in the scales).
- I used a Black and Decker Workmate as my workbench
- Hot water - To warm up the scales
- Thin bladed knife – To remove the scales (eg Vic 58mm)
- Duct tape
- 2oz peening hammer
- Pointed punch, to guide drill
- Screw to use as punch to push out old pin
- Electric drill with 1.5mm drill bit - or a Dremmel
- 1.5mm brass rod cut to size
- Tweezers to hold the bushings!!
- And my most used tool?! - A loup/eye-glass, to see what the h3ll was happening!!
Kampfer - If you are reading this - Remember a comment in your Style vs V58 thread recently, the tool positions on the Vic, and a potential mod you migt do
There's no excuse now - Go for it!!