I Got the Blade Wire Glue Blues...
The one part of fencing I enjoy least is re-wiring my foils. I have
tried a variety of glues and approaches over the years, but being a
recreational fencer, I don't get nearly as much practice as a team
armorer. Even when I succeed in getting a foil re-wired, the glue
always lets go before I break a blade, and then I get to start over.
THE TESTS: So, I decided to get 'scientific'. I got a dead blade, and
a gaggle of different glues. I cleaned the old glue out of the groove,
and sanded the interior with 600 grit emory paper, followed by an
*** wash. I sacrificed a blade wire and chopped it into 4 inch
pieces. These were bent into a square U shape roughly an inch across
the bottom. I then glued one piece into the blade using every type of
glue I could lay my hands on. Once the glue had cured, I used a spring
scale to measure the force required to pull the wire out of the groove.
The results (with additional comments) are tabulated below:
Borden's Krazy Glue: This is one of the original cyanoacrylate ester
cements, and is fairly thin (low viscosity). I placed the wire in the
bottom of the groove, and flowed the glue in on top. The glue was thin
enough to immediately flow down and around the wire, as well as soaking
into the fiber wrapping. I made sure I applied enough glue to cover the
wire, although this was a bit difficult because it's so runny. I
imagine it's almost impossible to get out of the groove if a wire breaks,
without using *** solvents. Slight solvent smell, and you MUST be
careful NOT to glue things (like your fingers) that you don't want to.
It sets up fairly quickly, but in the thickness used here, it's probably
safest to give it an hour or more to set up. The tube I had is very
small, and is probably not enough to do more than 2 blades (if that).
Clean up and/or mistakes have to be attacked with acetone.
Krazy Glue Pull Strength: ~ 2 1/2 to 3 pounds (wire broke)
'Power Stix' Hot Melt Glue: This was the only hot melt glue I could
find that made any claims about adhering to metal. Even after a good
warm-up period, the glue is a bit viscous coming out of the gun. I held
the glue gun vertically, and tried to 'squirt' the glue down around the
wire, which was placed in the groove beforehand. It might help to heat
the blade up prior to wiring, but this could get tricky. I couldn't
tell that the glue actually got under the wire. No *** solvents, but
the glue and gun can give you a *** burn. Direct contact of the gun
tip to the blade wire could melt the insulation. It is probably full
strength within 1/2 an hour, and shouldn't be too hard to remove for a
Hot Melt Glue Pull Test: ~ 1 pound
Weldbond Glue: This is the favorite at the Boston Fencing Club, and it
has the advantage that it doesn't use any *** chemicals, and can be
cleaned up with water if you are quick about it. It's a white glue, and
looks just like a casein based woodworking glue. In my experience, the
moisture in the glue can cause rusting in the groove, and over time it
can turn brown and brittle. Most of my more recent wiring failures have
occured with this stuff. It is quite thick, and skins over quickly. I
ran a bead down the groove, and inserted the wire down into the glue,
which is much easier to do with a little piece than with a full wire.
Full strength requires curing overnight. It's fairly easy to clean out
of a groove after it fails.
Weldbond Glue Pull Test: ~ 1 pound (failed rather abruptly)
Duco Cement: This is a plastic & solvent based glue, and the smell
suggests that it will kill off grey cells with little coaxing. It's not
as viscous as Weldbond, but stills skins over fairly quickly. I put the
wire in the groove, and tried putting the glue on top, but the Duco was
thick enough that I had to pull the wire up and reseat it to make sure I
got glue down in the bottom of the groove. Even after curing overnight,
there was a bit of residual solvent smell when I pulled the wire out the
next morning. Fairly easy to clean out for re-wiring.
Duco Cement Pull Test: ~ 3/4 pound
Cementit: I think this is a European version of Duco, and it's another
solvent/plastic type glue. I obtained it from one of the fencing supply
houses as 'blade glue'. The solvents are different, and smell even
nastier than those used in Duco. It's generally similar to Duco,
including smelling of solvent after a 12 hour cure, but the viscosity
is even higher than Duco, and it's harder to work with.
Cementit Pull Test: ~ 1 pound
Zap CA: This is another thin cyanoacrylate ester adhesive sold in model
shops. The only major difference between Zap and Krazy Glue is that Zap
appears to be even lower viscosity than Krazy Glue, and it comes in a
bigger bottle. It would also be a pain to clean up for a re-wire.
Zap CA Pull Test: ~2 pounds
Duro Quick Gel: This is a thickened cyanoacrylate. It's quite thick,
and would be very difficult to get down around the wire. I ended up just
running a bead on top of the wire. Even so, it was stronger than some
of the more conventional glues.
Duro Quick Gel Pull Test: ~ 1 1/2 pounds
CONCLUSIONS: The cyanoacrylates are the clear cut winners from a
strength standpoint. The thin versions can be flowed into the groove
around a wire, which makes life MUCH easier than working with a thick
adhesive that skins over quickly. The solvent smell isn't too bad, but
they'll be a pain to clean up for a re-wire job. On the other hand, if
the wire never comes out of the groove, re-wires should be few and far
THE NEXT PHASE: So, armed with this, I re-wired a blade using Krazy
Glue. It went fairly smoothly, and I'm pleased with the results.
However, I had a few minor problems I'd like to throw open to the
experts out there:
1) I put the wire in the groove, and held it to the tang with a
couple of clothes pins. I then put a bit of an arc on the blade
to tension the wire. Held 'horizontally', the glue tends to run
down towards the ends, making it difficult to cover the wire in
the middle of the blade.
2) In order to prevent the glue from running down the wire onto the
tang, or worse, into the point, I had to put something on the wire
at the ends. I tried a drop of candle wax, and that worked. I
suspect there is a more elegant approach to this problem.
Ideally, there may be another brand of cyanoacrylate cement that is just
slightly thicker than Krazy Glue. I'm looking for something thin enough
to flow down under the wire, but then not wick down toward the ends.
You can also buy 'accelerant' for cyanoacrylates, which might allow more
control of the curing process.
I know that a number of people have switched to using cyanoacrylates for
blade wiring, and I have to agree, it looks very promising. Any help on
the last few details of the process would be much appreciated.