Ferrule Tutorial

[ZDP-189]

This thread is a tutorial regarding the fitting of ferrules to a traditional Scandinavian-style knife.

The blade, ferrules and screw top were ordered from Attleborough Accessories (http://www.attacc.com). In this case, I used parts for a Brusletto Granbit. This is not available in a full kit, but you can get the individual parts separately.

Ferrule Fit
http://l2i.org/Granbit1.jpg

First, let's look at what we have to work with. The blade was pressed from sheet steel, and so is mercifully even in terms of width along the tang to the blade's ricasso. Even so, I checked with a pair of dial calipers, before sliding the front ferrule on. Here, you can see a gap caused by the ferrule slot beint too wide for the blade. Using a feeler gauage, I determined that it's only 0.15 to 0.25 mm spare, but that's a whopping chasm in terms of knife fit. We'll have to deal with that later.

Ferrule Fit II
http://l2i.org/Granbit2.jpg

The blade is also a teeny bit wider than the ferrule top.

Blade Finish
http://l2i.org/Granbit3.jpg

Also, when they punched the blade, they nipped the shoulders. It's not a big deal, but I'll sort that out before we start.

Grinding the Blade Flush
http://l2i.org/Granbit4.jpg

I mounted the blade in a grinding jig, which is basically two pieces of hardened steel with screws holding them together. I then worked the pinched ricasso and upper blade shoulder with EDM stones and Silicon Carbide paper glued to a stick. In honesty, I used my grinder to turn an hour's work into two seconds', but it could be done by hand.

Truing up the Plunge Lines
http://l2i.org/Granbit5.jpg

This is another step that isn't really necessary in a ferrule tutorial, but I feel it's necessary to clean up the plunge lines. There's a reason why Bruslettos are famed for their performance, but their knives are cheap. It's because they are let down by imperfections due to their mass production. I've just eliminated the last of those imperfections. Again I useed a combination of grinder and EDM stones. Note that if you are going to use a grinder, I'd recommend a 3M Trizact CF 'gator' belt at low speeds. Be careful not to heat the blade too much.

Also, notice how I am using a black plastic project tray to hold the parts? That's a good idea, because specially ordered unique knifeparts have a wau of escaping under their own steam. Keep it all together in a tray or tin.

Mark the Wood Block
http://l2i.org/Granbit6.jpg

I could have done something really fancy with stacked pieces of wood, pewter and horn. I didn't because the Granbit has the potential to look lovely if kept really simple. I wanted to highlight the fit and finish, rather than the construction.

Here I marked out a piece of 'super' grade curly birch, from Brisa (http://www.brisa.fi). I have scribed the centre and offcut. I have also penned them in so they'd show better on the photo. That's not necessary.

Next, I cut off the excess and marked the centre on that end too. I determined how much to cut off by taking the maximum the tang would allow and then took off an extra 5mm to give the 'knott' (long screw nut) some thread to hang onto. Why so long? Normally, I take the width of my palm, then add a cm for gloves, but in this case, I felt the long blade of the Granbit deserved the extra long handle. I was right; the handle ended up only 2cm longer than my palm and the balance point is at the join of the front ferrule.

[ZDP-189]

Drilling the Tang Slot
http://l2i.org/Granbit7.jpg

It's not really a slot! I simply bored it out with the drill press. Even my big ol' press dooesn't have enough travel to bore a whole birch block, so I came up with this solution some time ago.

By aligning the machinist's vice to the drillbit and positioning the block's scribe lines correctly with respect to the bit, I can get a perfect alignment. I drilled the one side to the full 75mm stroke of the press, then moved the block up in the vice, drilled a bit more, then flipped it over, realigned it and drilled till the two sides joined like the Channel Tunnel.

Slotting
http://l2i.org/Granbit8.jpg

This is my slotting saw. It is comprised by three jigsaw blades soldered together and stuck into a file handle. They are plenty sharp and cut wood well on the pull cut. A dozen pulls on each side was enough to let the blade slide home.

Why didn't I just bore the hole wider? Well, the main part of the tang is 10mm wide. The bit behind the ricasso widens to about 14. If I drill a 15mm hole, it'd be almost as wide as the ferrule.

[ZDP-189]

Mark Around Front Ferrule
http://l2i.org/Granbit9.jpg

I needed this mark to tell me where to cut. I used the tang to locate the ferrule at the centre of the block.

Mark Around Rear Ferrule
http://l2i.org/Granbit10.jpg

I did the same at the other end. This time, I used the centre scribe lines, because with the excess yet to be sanded from the wood under the ferrules, the block was about 3cm longer than it'd end up and the knott didn't yet meet the threaded tang.

Mark Handle Profile
http://l2i.org/Granbit11.jpg

I marked on one side only. Two lines were lined up with the widest part of the ferrules and the perpendicular lines showed the bit that would go inside the ferrules. I then freehand marked the position of the hand swell. Notice that this went wider than the ferrule-ferrule lines.

Cut Profile
http://l2i.org/Granbit12.jpg

I then cut the profile with a hacksaw/coping saw. Actually, I used a bandsaw with a 1/4" woodcut sawblade, and this is just mocked up, but it illustrates the technique. Be sure to err on the side of generosity. You can sand away, but not add back!

Fit Ferrule
http://l2i.org/Granbit13.jpg

This is the most tricky bit. It has to be done by steps. Test fit, sand or file, test fit, sand again, etc. By forcing on the ferrule, I left smears of nickel silver oxide. This showed me where the contact points were.

I first sanded only to remove the bulk of the material. Fine fit was done with a file. I used long sweeping motions along the arc of the ferrule, rather than straight filing.

I worked to get the join square. I first focussed on the inside where the ferrule joins the wood. I needed that square.

I also worked around the join so that it would seat the ferrule all the way round. I test fitted, looked for a gap, sanded the bit that was preventing a perfect join and tested again.

Once I had done both sides, I tapped the ends on with a rubber mallet, so that there was a little element of force fit. It assured a water-tight fit. This time, I found that by adding thick leather liners to the bench vice for protection, I was able to force the ends on with the vice. I was not using a lot of pressure, just holding them tight.

I also went through another few rounds of test fitting and filing. Here's a tip, to get the front ferrule off, use the threaded tang rotated 90° and pull. For the back, use a screwdriver, but be careful not to dammage the knife or yourself.

I wish I had more photos of this stage to show you, but I got carried away in the endless rounds of test fitting.

[ZDP-189]

Sorry, there are no photos for this stage.

I screwed the knife together, applied a kitchen towel and masking tape 'workshop sheath' to protect the blade and myself, and sanded the handle flush to the ferrule.

It is important to follow the graceful lines of the ferrule angle and flow one ferrule into the other with a continuous arc, or your handle will look like a chunk of wood with two bits of metal stuck on the end.

Also, sand the handle as symmetrically as possible. I used a combination of lengthwise sweeps and rotations against the contact wheel, platen ans slack belt portions of my grinder. It's more a matter of feel than anything.

Do whatever you are familiar with, but keep the lines flowing, avoid undercutting or excessively gringing the ferrules. You can mark them, but not grind them.

Finally, I went straight from the P40 alox belt to a P320. You can do that on soft nickel and soft wood. I would have used a P600 if I had one. The idea is to take out the P40 scratches without changing the shape of the wood. Then I masked off the wood, gave the ferrules a quick buff with white soap to reveal the remaining P40 scratches, which I took out with a 6" P240 scotchbrite wheel on a medium speed (1,370 RPM)

Next, I masked the ferrules and sanded the wood with P320, P600, P1200 and P2000, as small patches of dry Silicon Carbide paper held between thumb and forefinger. You don't need to work long with each grade, you just need to work out those scratches. A keen eye and good light helps more than hard, vigorous 'elbow grease'.

Don't clamp up! You'll mark the wood. At one point, I clamped the drill bit I originally used to bore the tang slot into a vice and slid the shaft on there. Do whatever works, but don't mark your wood.

[ZDP-189]

And then I did something really tricky.

Check Fit of Ferrule Against Blade
http://l2i.org/Granbit14.jpg

That join really annoyed me. On a regular bolster, I'd have wacked it tight with a hammer or a vice and then silver soldered it. But I couldn't deform the ferrule and I couldn't silver solder into a wide gap, because the solder wouldn't wick itself in. Besides, I didn't want to risk warping the tang at this late stage.

But that gap had to go.

Apply Heat Glue
http://l2i.org/Granbit15.jpg

First I applied heat glue to the outside of the gap. Heat glue is great because it holds tight, is viscous and won't wick, and removes easily. It will work with extreme low temperature alloys and epoxy, but not regular solders or braising spalter.

The glue created a temporary dam to stop the alloy leaking out.

Heat and Pour Bismuth Alloy
http://l2i.org/Granbit16.jpg

My CerroTru casting allow is a bismuth-tin alloy from High Tech Alloys (http://www.hitechalloys.com). It's expensive, but I use it sparingly. It contains no lead and is kitchen safe. Melting point is about 281°F and I can melt it with a heat gun. My gun is set up as in the picture above, so the mini-coffee jug pours the melted alloy from the bottom and leaves the oxides on top.

The idea here is to invert the assembled blade and ferrule, and pour a tiny amount of alloy into the ferrule. This creates a perfect seal against moisture.

Why not use epoxy? I imagine most of you will. I used this silver coloured alloy, because if any shows in that gap, it'll look like the metal surrounding it. i.e. it isn't there, and neither is the gap.

[ZDP-189]

I had to remove a sliver of wood from the front of the block, but then it was ready for assembly. I test screwed it together one last time and checked the joins again.

Then, I clamped the blade and front ferrule upside down in the vice and poured in clear set epoxy. This makes for the best joins because it sets transparent and has a 30 minute pot life, which is more time than the frantic 5 minute 'rapid' stuff and less boring than the 12 hour variety.

I slathered epoxy on the tang, then slid on the shaft and tapped it in place. {Note that although I has sanded flat the rim of the ferrules, each ferrule is slightly different and I had marked and noted which side fits the edge side on the front and rear ferrules and the shaft.} I filled the bore hole with epoxy and let the bubbles rise. Then added more, let those bubbles out, and so on, until the shaft was full. I then added a bit more around where the rear ferrule was to go and added the back ferrule and 'knott screw', wiping up all the epoxy that oozed from all spaces.

I tighedned the screw by clamping it in a leather jaw lined vise and rotating the handle. Over tightening will deforem the ferrules, so don't do that.

You don't need to wait till the epoxy is dry on this kind of knife to start buffing. Indeed, the epoxy is redundant. I like it though, because it seals the tang from rust.

After a final sanding with P1200 and P2000 paper, I alternately masked off the ferrules and wood and separately buffed them. I used white then green soap on the ferrules and no soap and a fresh mop on the wood. Buff only lightly on the wood, till you can see the grain pattern.

[ZDP-189]

Time for oiling.

Painting it On
http://l2i.org/Granbit17.jpg

You can soak your handles. You can even vacuum-saturate them. In this case, I painted it on. I have found that even after I had soaked a handle for some weeks, the penetration was not as much as I had thought.

This time, I pained the Danish Oil on coat after coat till the wood would absorb no more. Then I added more after dinner.

Desired Effect
http://l2i.org/Granbit18.jpg

You don't want to over oil your handle and make it really dark, hiding the grain and its wonderful translucency and depth.

At least, IMHO ;) Everyone has their own way.

[ZDP-189]

So this is the final product. It fits.

http://l2i.org/Granbit19.jpg

http://l2i.org/Granbit20.jpg

http://l2i.org/Granbit21.jpg

http://l2i.org/Granbit22.jpg

http://l2i.org/Granbit23.jpg

http://l2i.org/Granbit24.jpg

[Tiffers]

Superb! Now I have the confidence to have a go at a similar kit I have! I just need to find some time from somewhere!!! :D

Thanks for that Zdp :)

Tiffers

[ElThomsono]

Wow, fantastic work :)

That's a great knife, especially seeing just how much care and attention went into it:

http://l2i.org/Granbit22.jpg
Join? What join? :D

Thanks for that, it was a really good read :happy15:

[Basemetal]

Breathtaking Dan! Thanks for that :cool20:

I've long since learned to wear a snorkel when reading your tutorials :lol:

:snorkel :snorkel :snorkel

[ZDP-189]

Breathtaking Dan! Thanks for that :cool20:

I've long since learned to wear a snorkel when reading your tutorials :lol:

:snorkel :snorkel :snorkel


Yeah, and get a fast broadband! :rolleyes:

[Basemetal]

Yeah, and get a fast broadband! :rolleyes:

Nah...one day soon you'll discover the hide buttons...:rolleyes:

:snorkel

[ZDP-189]

If you ask me Tiffers, it's a lot more work than a regular scandi if you do it right. It's also a lot easier to mess up and there's less opportunity for customisation.

[Tiffers]

Perhaps its the less oppurtunity for customisation which appeals. Sometimes having the ability to do something from your own head can be a bit scary especially when you are just starting out. When you have a form to follow its easier (in my mind) to concentrate on picking up the skills you lack.

Tiffers

[MotorbikeMan]

Stunning tutorial Dan, seriously good job :biggthump :biggthump

[Bazza]

Great work Dan, why didn't I discover that trick with the drill table years ago, it will now save me hours of frustration, drilling tang holes!
:jumping43:
Barry

[bardster]

Fantastic!! What can I say, puts my feeble efforts to shame.. :( I might scrap it and start again..

My biggest problem is lack of patience, I tend to rush things too much and then make mistakes.

[Tvividr]

Extremely nice work Dan ! Not even the pro noggin custom makers could do it better !

[Kevin]

Yep..good work Dan......

Those gaps in the ferrules are problems.....and you handled it well. I have some low temp pewter and would have done the same to seal it.

Every knife has its problems, and its knowing how to recover from those problems that makes all the difference :)

[ZDP-189]

Fantastic!! What can I say, puts my feeble efforts to shame.. :( I might scrap it and start again..

My biggest problem is lack of patience, I tend to rush things too much and then make mistakes.

Dude, It wasn't my intention at all to show you up. I just want to show the new makers who haven't tried it - like Tiffers - how to do it and get a perfect fit.

Everyone here knows I have a fair amount of experience and a big workshop full of kit. Also, as the fit and finish of this knife are going to be scrutinised, I put every ounce of effort into getting it perfect. These efforts are uneconomic. I would have to charge upwards of £65 to make a knife like this. Before I sped up my production rate, I would have had to charge more like £150 just to cover my labour!

As I wrote in your thread, your second knife shows you probably didn't need a tutorial after all. The fit of the ferrules looks good. Better even than I have seen an experienced maker do.

All you have to do is flow your lines a bit more and maybe employ some of my tricks to tweak and fix the factory's errors.

Consider this a challenge - knock our socks off with the pure fit and finish of your next knife :D

[Sajuma]

You are the man! You take your work extreme with your care and wits! I know how time consuming those ferrules can be but the finish on this one is something out of this world. Congrats and keep those knifes comming!

Juha

[ANDYLASER]

WOW, that is an impressive tutorial. Excellent work Dan.

[Inspector71]

Very very impressive. Top tutorial. Although it's scared me off ferrules for the time being I think... :)

Come to think of it I have to say I've never really liked them to be honest. But looking at your take on it my doubts have probably been down to factory fit'n'finish before. They can actually look quite good when fitted well. As was said earlier though they do kind of limit some of your options...

Once again, great tutorial.

[Hepotec]

That's brilliant.

[Basemetal]

Bumped for newer members :)

[parismcmahon]

It's a great tutorial ... I certainly could have done with it before the two or three ferrule fits I have completed with various degrees of success. Actually the ferrules at the front for some reason I've been more successful with - the one's at the back end seem to be more of an issue for some reason (and end caps!) ... still now I know how to do it properly there's no excuse. Not sure I'll be cooking up bizmuth alloy in my kitchen yet tho!

[MeetTheGeeks]

excellent mate, thanks for this one. Same there was no pics for the hot metal ferrule fixing. Maybe next time. Excellent work mate and great result

[ta2edfreak]

Thanks for the bump BM, this will come in handy soon. What about using copper sheet for a ferrule, is that ok? ZDP, great tutorial.

[Basemetal]

Copper sheet? You mean for a bolster or a ferrule?

[ta2edfreak]

For a ferrule. I saw a pic somewhere that used copper ends and just flattening them out a little but what about for a bigger knife? Cut some sheet solder it round, solder and end and cut the slot?

[parismcmahon]

Anyone know where I can get the Brusletto factory made Granbit FRONT Ferrules still - since they've discontinued them Brusletto no longer supply them and I've tried most of the usual suspects (Brisa, Good Stuff in Denmark etc) Perversely I have TWO back ferrules and ONE end nutt!? At a push i suppose I could use a Lauri 22mm nickel silver one but the Granbits are 25mm and a bit thicker and nicer ... To be honest am also using the 100mm standard stainless finished Brusletto blades so if anyone has a couple of Granbit blades knocking about then I'd take them off your hands!

[Baldur]

By far the best tutorial on this subject I have seen. This has helped me a lot. Thank for sharing this!