I
hate soldering guards. Actually, it would be more accurate
to say that I hate cleaning up and burnishing the solder
joint. Have you ever finished soldering only to find
one little spot where the solder didn't flow and seal
the joint?
How about getting a good seal, then while cleaning up
the joint, you put a scratch on the face of the guard?
Then while fixing the scratch on the guard, you accidentally
scratch the face of the ricasso. Ever go back and forth
until you were ready to scream? Fix the ricasso -- dang!
-- fix the guard, fix the ricasso, fix the guard...
Ever finished a knife that had a perfect joint, cleaned
and burnished great with no scratches, then six months
down the road, a little rusty pit starts to appear
from hidden flux that leeched out? And you did everything
you could to neutralize the flux before assembling
the knife.
I've been through every one of these scenarios, plus
some. It's frustrating, and I've talked to many a well
known maker who grinned at the mention of this plight.
The technique that I'll demonstrate today is based
on a method shown to me by Jerry Fisk several years
ago. It's a form of solderless guard using JB Weld
to seal the joint. The technique shown here will employ
a pressure fit guard with JB Weld as the sealing agent.
During this tutorial, I will throw in a few free tips
along the way to keep things interesting. I'll also
try to anticipate and answer any questions as we go.
I hope you'll find it interesting and enlightening.

This method of fitting a guard demands
good, close fits. We want everything as close as possible,
with no visible gaps. I start by filing a guard stop
on the back of the ricasso. This is done with a filing
fixture. The fixture is hardened toolsteel. The face
is hard enough to resist the agressive bite of a file.
Those vertical marks you see on the fixture aren't
cuts from the file. The surface was essentially polished
when the file hit those areas.
For this step I first mark where I want the guard
to stop, then align it in the fixture, and clamp it
tightly. This is followed by filing right down to the
face of the fixture. When the file looses it's bite
and just skates across the face of the fixture, you
know you're there. The end result is nice, flat, perfectly
aligned shoulders.
If you were using an air hardening
steel, you would obviously do this prior to heat
treat. The blade pictured
above is 5160. On carbon steels I often wait until
after heat treating to file in the shoulders. I always
draw the tang and ricasso areas back to spring temper
with a torch after heat treating anyway. This gives
incredible strength against ateral forces. It also
facilitates easy filing, drilling, tapping, etc.
You can use a round file instead of a flat file if
desired,
to create a radius at the tang/ricasso juncture.
This helps avoid mechanical stress points.
Okay, let's move on to the next step. Once the shoulders
are to my liking, I check the dimensions at the tang/ricasso
juncture with calipers, so I'll know what size the
slot in my guard needs to be.

Here I've milled the slot for my guard and am checking
it with calipers. I have ever-so-slightly undersized
the slot. This one will be a pressure fit guard. That
means that it won't quite reach the guard stop I made
in the previous step. I will have to gently tap it
down to rest against the stop with a seating tool.
You may have noticed that all I have in the mill is
a rectangular piece of nickel silver. I don't shape
the guard until after I've made the slot and have a
good fit. That way, if I mess up the slot, I haven't
wasted a lot of time.
By the way, if you don't have a milling machine, you
can still get very close fits. Drill several holes
in a line where your slot will be. Align the guard
in the filing fixture where one side of the slot is
to terminate, and file right down to the fixture. Flip
the guard over and do the same thing for the other
side of the slot. I did it this way for years.
Now we're ready to do a dry fit and see how well things
flush up. Hopefully, I've measured properly and there
won't be any unsightly gaps at the joint.

This
is a dry fit test. Slide the guard up the tang until
it stops. Remember, this one is pressure fit and hangs
before it hits the guard stop I made. That's where
my ultra-sophisticated seating tool comes in. It's
nothing but a foot long block of maple with a slot
cut in it. The slot in the seating tool is placed over
the tang and butted up against the back of the guard.
Then I gently tap until the guard rests flush against
the guard stop. You can use any hardwood for this tool.
I've heard of some people using pipe. I like wood because
there's not much chance of dinging up the back of the
guard.
Okay, now that we've got it seated, let's remove the
blade from the vise and see how well everything fits.

This
isn't too bad. There are no glaring gaps and everything
mates up pretty nicely. I see that there are some small
burrs around the slot that need to be addressed. A
couple of swipes with some 600 grit paper around a
piece of steel will fix it up just fine.
Now that I know I have a fairly successful fit, I'll
remove the guard and rough out the shape. The next
time you see that chunk of nickel silver it will actually
look like a guard. It's also time to move on to the
JB Weld we'll be using to seal the joint.

The
guard and finger groove have been been roughed out
and it's time to seal everything up. We want a clean
surface
for our seal. I cleaned the guard, the slot, the back
of the ricasso area, and the tang with hot soapy water,
then rinsed well and dried. You can also clean and
degrease everything with acetone, ammonia, or isopropyl
(rubbing)
alcohol.
A small quantity of JB Weld was mixed up and
spread on the back of the ricasso, around the tang, and
in
the guard slot with a Popcicle stick. Notice that I
have covered the blade with masking tape to keep the
finish clean. Now we're ready to put it all together.

The
guard has been affixed and we have a nice bead all
the way around the joint. You don't have to put as
much of the JB Weld as I did, because this is after
all, a tight fit. I just wanted to be sure that you
could clearly see the bead, and the cleanup in a later
step.
We are going walk away for a while now and allow the
JB Weld to begin curing. The amount of time seems to
vary according to temperature, humidity, etc. What
I do is check the consistency periodically with a toothpick.
I am looking for a firm rubber consistency. Around
my shop, it's generally about 45 minutes to an hour
before it's ready.
But check it frequently in your shop. Whatever you
do, don't let this stuff fully cure before you do the
cleanup step! JB Weld is tough stuff. It can be drilled,
threaded, and filed. There are reports that it has
been used to repair cracked engine blocks. So keep
an eye on, okay?

While
we're waiting for the JB Weld to set up a bit, let's
take a look at what we'll be using to clean up the
joint. Notice, no gravers or sandpaper. Our entire
set of "tools" is a can of WD-40, a bit of
bathroom tissue (yes toilet paper), and the same Popcicle
stick we used to apply the JB Weld. That's it.
I merely clipped off the part of our stick that had
been used. Notice that I made a diagonal cut. You'll
see why in the next step.
While we're here, you may have noticed the round plastic
disk with some JB Weld on it. That is a plastic coffee
can lid. This is what I use to mix my epoxy and my
JB Weld. The stuff won't permanantly stick to this
type of plastic, so I can use them many times. After
the epoxy or JB Weld has fully cured, all you have
to do is bend the plastic. Whatever is stuck to it
will pop off. Any sticky residue can be removed with
acetone.
Alright. The JB Weld has setup to a hard rubbery consistency.
Let's go clean up that joint.
To continue this tutorial click
here.
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