August 5, 2025 • 20 mins
Can you imagine a luxury timepiece—sleek, precise, elegant—held together not just by screws or lugs, but by invisible champions: adhesives? In this episode of Adhesion Matters, we turn the spotlight on how modern adhesives have quietly become indispensable in both walk-your-line mechanical watches and cutting-edge smartwatches.
What’s Inside:
- From Shellac to Synthetics
Explore how traditional binding agents like shellac once ruled watchmaking—and how synthetic adhesives now let us achieve ultra-thin profiles, strong water resistance, and seamless finishes. - Miniaturization Meets Adhesion
Why are adhesives more critical than ever? Because today’s watches demand lighter components, micro-assemblies (magnets, prisms, buttons), and watertight seals—often in sub-millimeter form. Adhesives are working at scales no tool can touch. - Smartwatch Secrecy & Bonding
Think through curved displays, flexible circuitry, and dustproof enclosures. We discuss how adhesives help keep water out, parts in place, and form factors slim—without sacrificing durability or aesthetics. - Aromatics & Substrates: Bonding the Toughest
Discover the art of sticking sapphire crystals, ceramic bezels, soft silicones, and delicate composites—each demanding precise adhesive chemistry and bond-line finesse. - Watchmakers’ Tools of Choice
From UV-curing cements that vanish once cured (perfect for crystal clarity), to hypo cement with ultra-fine applicators for watch hands or dial feet—craft and chemistry meet elegance. - Why It Matters
Adhesives aren’t just hidden—they’re enabling miniaturization, performance, and beauty in every tick. Whether you’re repairing vintage icons, designing the next luxury watch, or integrating flexible circuits into wearables, understanding adhesives gives you the invisible edge.
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Lucas Adheron (00:00):
What if the true unsung hero of a watch isn't its
intricate gears, its sparklingjewels, or even its precision
movement?
What if it's something youcan't even see?
Something that's fundamentallychanged how they're made and how
we interact with them.
Today, we're talking aboutglue.
Seriously, welcome to the DeepDive.
Get ready to join us as we peelback the layers, pun absolutely
(00:20):
intended, on the hidden worldof adhesives and watchmaking.
We're going to use the materialyou've shared to uncover how
glues, sealants, bonding agents,how they've become utterly
indispensable to moderntimepieces.
We'll trace their journey fromhumble beginnings right up to
some truly cutting-edgeapplications.
Eleana Bondwell (00:36):
Yeah, and what's really fascinating here
is how something so, well,seemingly simple as glue has
profoundly reshaped an industry,an industry long renowned for
its mechanical precision, itsintricate craftsmanship.
It really is a journey fromtraditional artistry to
high-tech manufacturing.
Lucas Adheron (00:53):
Exactly.
And by the end of this deepdive, you'll have a shortcut to
understanding the, let's callthem, sticky secrets of watch
design, a surprising history youprobably never expected, the
diverse chemistries at play, andsome really interesting
trade-offs between durabilityand Well, repairability.
You'll gain a whole newappreciation, I think, for how
the watch on your wrist isactually built.
Okay, let's unpack this then.
(01:15):
Why the shift?
From traditional mechanicalfasteners, screws, and things to
adhesives.
When I think of watches, Iimmediately picture tiny screws,
springs, not screws.
Well, not glue.
What drove that fundamentalchange?
Eleana Bondwell (01:29):
That's a great question, and it really comes
down to a couple of things.
Evolving consumer demand andnew technological capabilities.
People now want watches withthinner profiles, lighter
materials, much better waterresistance, and of course, the
seamless integration of complexelectronics, especially with the
rise of smartwatches.
Mechanical fasteners with theirbulk, their limitations.
(01:50):
They just couldn't keep up withthese demands without
compromising the design orperformance.
Lucas Adheron (01:56):
Right.
They take up space.
Eleana Bondwell (01:57):
Exactly.
And modern adhesives offersolutions that traditional
mechanical fasteners simplycan't.
They enable truly seamlessjoints, provide superior
sealing, better protection fromthe elements.
And crucially, they allowmanufacturers to bond completely
to similar materials.
Think metal to glass or plasticto composite.
You can do that withoutcompromising structural
(02:18):
integrity or adding significantbulk.
Lucas Adheron (02:20):
So it's not just about ditching the screws.
Eleana Bondwell (02:22):
Not at all.
It's about pushing the verylimits of what a watch can be,
how thin, how waterproof, howintegrated it can become.
Adhesives really unlocked anentirely new design language.
They're critical for achievingthe performance, the longevity,
and the sleek aesthetics weexpect today.
Lucas Adheron (02:39):
It's wild to think about how far back this
idea of glue goes, though.
Even before anyone was dreamingof telling time with a tiny
machine on their wrist, thehistory here is far deeper than
I ever imagined.
Eleana Bondwell (02:50):
Oh, it's astounding.
We're talking maybe 200,000years ago, Neanderthals using
birch bark tar.
Lucas Adheron (02:56):
Birch bark tar.
Eleana Bondwell (02:57):
For what?
To haft stone tools, basically,sticking the stone head onto a
handle.
Lucas Adheron (03:02):
Wow.
Eleana Bondwell (03:02):
Then fast forward, you've got ancient
civilizations.
The Egyptians, maybe 1,500 to1,000 BC, using animal glue for
wood bonding.
You can see it into Takamun'scoffin.
And the Romans, the Greeks,they refined animal and fish
glues, even adding things likeegg whites, blood, even cheese,
apparently.
Fish.
Lucas Adheron (03:21):
Seriously.
Eleana Bondwell (03:22):
Seems so.
So the basic idea, theunderstanding of adhesive
properties for precision, fordurability, has been around a
very, very long time.
Long before watchmaking as weknow it.
Lucas Adheron (03:32):
But when did it really make its proper
horological debut?
I'm picturing some old schoolwatchmaker hunched over a bench,
pulling out a pot of...
shellac, was it?
Eleana Bondwell (03:42):
You're absolutely right.
Shellac.
It's a natural polymer actuallysecreted by the lac bug.
It was historically reallysignificant in watchmaking.
It's key property.
It's thermoplastic.
Melts at a relatively lowtemperature, around 75 degrees
C.
Lucas Adheron (03:54):
Okay, so it melts easily.
Why was that useful?
Eleana Bondwell (03:56):
It allowed watchmakers to secure pallets,
those little jewels, on thelever plate.
They could gently heat thelever, soften the shellac, then
make incredibly precise, tinyadjustments to the pallets, and
then just let it cool to harden.
It fixed the jewels first, Ah,I see.
And the
Lucas Adheron (04:18):
crucial point, I guess, was that you could undo
it.
Eleana Bondwell (04:20):
Exactly.
It's reversibility.
You could undo it with heat,which allowed for future repairs
or adjustments.
That was vital for traditionalwatchmaking.
Lucas Adheron (04:27):
So that reversibility was key for
shellac.
Makes you wonder if modernwatchmakers sometimes wish they
had that easy undo button withall the permanent glues we'll
get to.
Eleana Bondwell (04:36):
Huh.
That's a fantastic point.
And yes, it touches on thechallenges we'll discuss later.
But for now, let's move fromancient glues and shellac into
the modern era.
What really kicked off thesynthetic revolution in
watchmaking adhesives?
Lucas Adheron (04:49):
Well, speaking of synthetics, I came across
something called GS Hypo Cement.
That sounds pretty specific.
What made that particularadhesive such a sort of pivotal
moment?
Eleana Bondwell (04:59):
It absolutely was.
GS Hypo Cement, invented backin 1939, was specifically
formulated for watchmaking.
That was the key.
It came with a very fineprecision applicator.
It dried clear, mediumstrength.
Crucially, it wouldn't damagedelicate surfaces like plastic
watch crystals.
So it became ideal for bondingthose plastic glasses, bezels,
little metal parts.
Lucas Adheron (05:20):
And what made it stand out?
Eleana Bondwell (05:21):
What truly distinguished it was its
controlled setting time.
It got tacky and about 10, 15seconds vital for making tiny
adjustments.
Then it dried in maybe 10, 15minutes and was fully hardened
after about an hour.
That controlled timing wasessential for delicate assembly
work.
You had a window to work.
Lucas Adheron (05:38):
Right.
Not instant, but not hourseither.
Eleana Bondwell (05:40):
Precisely.
And soon after, you getcyanoacrylates, what most people
call superglue.
Their introduction offeredextremely rapid bonding, which
opened up even morepossibilities for assembly,
especially for small, quickfixes.
Lucas Adheron (05:52):
This historical overview really sets the stage.
But the real strategic pivot...
The moment glue changed, notjust how watches were made, but
maybe how we think about owningthem.
That seems to be exemplified bythe Swatch Skin family, right?
This wasn't just about making awatch thinner.
It was about rethinking thewhole product lifecycle.
Eleana Bondwell (06:12):
That's absolutely right.
The Swatch Skin family,introduced in 1997, is the
perfect case study here.
In these watches, the movementis permanently sealed inside the
case.
They use a structural adhesivethat secures both the acrylic
crystal on the front and thecase back.
Lucas Adheron (06:27):
Permanently sealed, so you can't get into
Eleana Bondwell (06:28):
it.
Exactly.
The consequence of this designis, as the sources state, the
timepiece becomes invulnerableto environmental conditions,
moisture, dust, whatever.
But the flip side, and this iscrucial, is that they are
rendered maintenance-free, i.e.
impossible to service.
Lucas Adheron (06:43):
Wow.
Impossible to service.
That's a big shift.
Eleana Bondwell (06:46):
It's huge.
The shift fundamentallyprioritized robust sealed units
and frankly, cost effective massproduction over the traditional
model of repairability.
It moved towards products that,while incredibly durable when
sealed, are ultimatelydisposable rather than endlessly
serviceable, at least intheory.
It really redefined productlife cycles within that segment
(07:07):
of the industry, and it changedconsumer expectations for
certain types of watches.
Lucas Adheron (07:11):
And it's fascinating how we still see
that kind of dual approachtoday.
You have these cutting edgesynthetics for mass-produced
sealed units, but traditionalshellac is still being used for
delicate repairs and in high-endartisan craft where
serviceability is paramount.
There's still a balance.
Eleana Bondwell (07:26):
Precisely.
It reflects the diversity ofthe watch world itself.
Lucas Adheron (07:30):
So, okay, we've gone from tar and cheese through
shellac, GS Hypo, super glue,and now this era of
disposability, or at leastnon-serviceability, for some
watches.
Let's dive into the actualchemical arsenal a modern
watchmaker has.
It's not just one kind of glueanymore, is it?
It sounds like a whole paletteof polymers, each tailored for
specific jobs.
Eleana Bondwell (07:48):
That's a great way to put it, a palette.
The industry uses a reallydiverse array of adhesive
chemistries, each picked for itsunique properties and
suitability.
It's like a specializedtoolbox.
Lucas Adheron (07:59):
Okay, so what are the main players in this
toolbox?
Eleana Bondwell (08:01):
Well, first up, you have epoxies.
These are workhorses, widelyused for their high strength,
their durability, and excellentresistance to chemicals and
temperature.
They're typically two-partsystems, you mix them, and a
chemical reaction createsincredibly strong bonds.
Lucas Adheron (08:16):
Where would you use those in a watch?
Eleana Bondwell (08:18):
Crucial for structural bonding.
Think attaching glass orsapphire crystals to metal
cases, bonding metal to metalcomponents.
Sometimes even for settingjewels, though that's often
you've now.
You'll see things likequick-setting five-minute
epoxies for general repair,maybe specific jeweler's epoxies
like Vigors, or evenindustrial-grade ones like
Huntsman's Eroldite 2014-2 forreally demanding applications.
Lucas Adheron (08:42):
Like aerospace-grade stuff, almost.
Eleana Bondwell (08:44):
Pretty much.
Imagine that level ofstructural integrity scaled down
to a tiny component in yourwatch.
That's the kind of bondingwe're talking about.
Then there are silicones.
These are valued for completelydifferent reasons.
Exceptional flexibility, forone.
They also handle a hugetemperature range from cryogenic
right up to high heat and offersuperior moisture resistance.
Lucas Adheron (09:06):
Flexible and resistant.
Sounds good for sealing.
Eleana Bondwell (09:09):
Exactly.
They come in various curingformats.
RTV, room temperaturevulcanizing, is common, means
they cure without needing heat,which is vital around delicate
movements.
Their main job in watchmakingis case sealing, creating those
essential airtight andwaterproof barriers.
Dow's dowsilla adhesives are aprime example known for clarity
(09:29):
and They're the invisibleshields protecting the watch's
heart.
Silicones are also vital insmartwatches for protecting
sensitive electronics, sometimeseven used for damping
vibrations.
Lucas Adheron (09:39):
Right, protecting delicate components, not just
holding them.
Eleana Bondwell (09:42):
Precisely.
Next up, polyurethanes.
These are known for theirtoughness, their impact
resistance, and strong adhesionto lots of different materials.
They can be moisture-curing ortwo-part systems.
In watches, they're used forstructural parts and are
particularly good as waterproofglues for case sealing.
They provide really lastingresults against water exposure.
(10:03):
You might see chemistry similarto what's used in automotive,
like DuPont's BetaSeal, adaptedfor luxury goods where that
robust impact resistance isneeded.
Lucas Adheron (10:12):
Interesting.
And what about the quick stuff,superglue?
Eleana Bondwell (10:14):
Yep, cyanoacrylates are instant
adhesives, still very much used,they cure extremely fast,
right?
Room temperature, strong bondsin seconds, perfect for small,
precise bonding where you needthat immediate tack.
And for high-end goods, they'vedeveloped specialized
low-blooming and low-odorversions.
Avoids that white residue, theblooming you sometimes see,
keeps things looking clean.
Lucas Adheron (10:35):
Ah, good point.
And the last big category.
Eleana Bondwell (10:38):
UV curable adhesives.
These are a really significantadvancement because they offer
amazing control.
They pull Limerize or curerapidly seconds to minutes, but
only when exposed to specificwavelengths of UV light.
Lucas Adheron (10:52):
Cure on demand.
Eleana Bondwell (10:53):
Exactly.
Cure on demand allows forreally precise positioning of
components before you lock themin place.
They often have excellentoptical clarity, which is key.
Primarily used for bondingwatch crystals and glasses to
bezels and cases.
Also very important for pottingor sealing sensitive electronic
parts in smartwatches, wherethat clarity and precise
(11:14):
placement are critical.
Lucas Adheron (11:15):
So it's way more than just the core glues.
Sounds like there's some highlyspecialized solutions, too, for
very specific functions withinthe watch.
Eleana Bondwell (11:21):
Absolutely.
Beyond those main chemistries,watchmaking relies on other
things.
Like thread lockers.
Think Loctite.
These are used to secure tinyscrews and bolts against
vibrations, stopping them fromloosening over time.
Importantly, many formulationsstill allow for normal
disassembly later.
Lucas Adheron (11:36):
So they lock, but not permanently.
Eleana Bondwell (11:38):
Often, yes.
Depends on the grade youchoose.
Then there are dial adhesivesand tapes.
These can be tiny self-adhesivedots or double-sided tapes.
They're used for securing watchdials to the movement,
especially useful if theoriginal dial feet those little
pins that hold the dial getbroken during a repair.
It's a common fix.
Lucas Adheron (11:58):
Ah, practical solution.
Eleana Bondwell (11:59):
And then there's something really
advanced, surface modificationcoatings.
Aculon is a name you mighthear.
Now, crucially, these are notadhesives themselves.
They're nanoscale treatmentsapplied to the surface first.
Lucas Adheron (12:12):
To make the glue stick better?
Eleana Bondwell (12:14):
Essentially, yes.
They work by directlyfunctionalizing the substrate,
chemically altering the surfaceat a nanoscale so the adhesive
can form a much stronger, morereliable bond.
It reduces the chance ofdelamination or failure.
Plus, they can add otherproperties like making the
surface repel water orfingerprints.
It's about optimizing thesurface for the adhesive.
Lucas Adheron (12:33):
That's fascinating.
Really prepping the battlefieldfor the glue.
Eleana Bondwell (12:36):
A good analogy.
It ensures the best Okay,
Lucas Adheron (12:40):
with all these advanced chemistries and balls,
who's actually making thesesuper glues?
And how do they even get intothe hands of a watchmaker?
Are giants like Dow, DuPont,Henkel, and Huntsman just, I
don't know, shipping barrels ofthis stuff directly to
Switzerland?
Eleana Bondwell (12:54):
Well, not directly, usually.
It's more indirect.
These major global chemicalmanufacturers play a crucial
role, but often behind thescenes.
Their huge R&D efforts forreally demanding industries,
electronics, aerospace,automotive, produce
manufacturing, materials thatare directly transferable to
horology, the requirements areoften similar.
Precision, durability,resistance.
Lucas Adheron (13:15):
So the watch industry benefits from R&D done
for other fields.
Eleana Bondwell (13:18):
Absolutely.
For instance, Dow makesDowsolet instant adhesive, noted
for small items like watches,great clarity, works in extreme
environments.
DuPont has innovations instructural adhesives like
urethanes and epoxies used inautomotive, maybe EV battery
sealing chemistries directlyapplicable to strong watch
cases, plus electronic materialslike silicone lid seals.
(13:40):
Henkel, they're the world'sbiggest adhesive provider.
Their Loctite brand iseverywhere in watch repair and
manufacturing.
Thread lockers, retainingcompounds, instant glues, UV
curables, you name it.
Lucas Adheron (13:51):
Loctite, yeah, I know that name.
Eleana Bondwell (13:53):
And Huntsman with their Eroldite brand.
That's high-performanceepoxies, acrylics,
polyurethanes.
Again, often developed fordemanding electronics or
aerospace, needing that precisebonding and extreme durability
perfect for advancedwatchmaking.
The watch industry iseffectively leveraging solutions
developed for otherhigh-precision, high-reliability
fields.
It's a huge advantage.
Lucas Adheron (14:12):
Okay, so the big guys make the base chemicals.
How do they actually get to thewatchmaker's bench?
Eleana Bondwell (14:17):
Right.
It's a sort of multifacetedsupply chain.
On one side, you have largeindustrial distributors.
Bodo Möller Chemie is a goodexample.
They're premier globaldistributors of specialty
chemicals.
They don't just ship boxes.
They offer technicalconsulting.
They have labs for testingapplications.
They provide training.
They might be an authorizedHenkel distributor for example,
(14:39):
they bridge that gap between themassive chemical producers and
the more bespoke needs ofwatchmaking.
Lucas Adheron (14:47):
So they add expertise.
Eleana Bondwell (14:48):
Exactly.
Then on the other side, youhave the niche watch parts
suppliers, companies like PerrinWatch Parts, Time Connection
Inc., Esslinger & Co., GrobitUSA.
These cater directly toindividual watchmakers and
repair professionals.
They stock everything from theclassic GS Hypo Cement and
various Loctite products rightback to traditional pure
shellac.
Ah,
Lucas Adheron (15:09):
so they serve the repair side and smaller makers
more directly.
Eleana Bondwell (15:12):
Precisely.
It's this dual supply chainthat ensures the industry gets
both the cutting-edge industrialsolutions needed for mass
production and the continuity oftraditional materials essential
for the artisanal side, forrepairs, for heritage skills.
Lucas Adheron (15:25):
It's a blended approach, then, giving
watchmakers the best of bothworlds, from, like you said,
space-grade epoxies right downto time-honored shellac.
Eleana Bondwell (15:34):
That captures it perfectly.
Lucas Adheron (15:35):
It sounds like adhesives are truly magical for
watchmaking, then.
Enabling all sorts ofinnovations, unlocking new
designs, cleaner looks, thinnercases.
But there's always a flip side,isn't there?
What are the inherentadvantages clearly laid out and
what are the trade-offs?
Because I imagine as powerfulas these glues are, they must
come with some real challengestoo.
Eleana Bondwell (15:56):
Oh, absolutely.
The upside, the advantages arecompelling.
You hit on some already.
Huge design flexibility andaesthetics.
Cleaner, sleeker looks withoutvisible fasteners.
Thinner, lighter watches becomepossible.
They're fantastic at bonding tosimilar materials, metals,
plastics, glass, composites.
They overcome tricky issueslike differing thermal expansion
(16:16):
rates.
Lucas Adheron (16:16):
Meaning things expanding or shrinking
differently with heat?
Eleana Bondwell (16:19):
Exactly.
That difference can easilycrack a less flexible bond or
stress a mechanical joint.
Adhesives can often accommodatethat better.
Allows for really innovativemulti-material constructions.
They also provide even stressdistribution.
A glued joint spreads the loadover a larger area, unlike a
screw, which which concentratesstress at one point.
(16:39):
This improves strength,reliability, fatigue resistance.
Lucas Adheron (16:43):
Makes sense.
Fewer weak points.
Eleana Bondwell (16:44):
Right.
They also contribute to lightweighting and cost reduction,
replacing heavier metalfasteners, streamlining
manufacturing, reducing partcounts, labor, potentially
production costs.
And critically, they createhermetic seals for environmental
protection, vital for waterresistance, keeping out
moisture, dust, dirt.
And finally, some flexibleadhesives offer excellent
(17:06):
vibration damping.
They absorb Okay, that's
Lucas Adheron (17:11):
a strong list of benefits.
It also sounds too good to betrue.
So what's the biggest headache?
What are the real complexitiesand challenges for a watchmaker
or manufacturer working withthese high-tech glues?
Eleana Bondwell (17:22):
The challenges are significant and shouldn't be
underestimated.
First off, surface preparationand quality control.
This is absolutely critical.
Any tiny bit of impurity,oxidation, grease, or
contaminant on the surface canlead to weak bonds or outright
failure.
You can get defects likekissing bonds where surfaces
touch but don't truly bondchemically or porosity, voids,
(17:46):
tiny air bubbles trapped in theglue line.
Lucas Adheron (17:48):
And these are hard to spot.
Eleana Bondwell (17:50):
Incredibly hard, especially in miniaturized
components.
It demands meticulous cleaningprotocols and rigorous quality
checks.
Get the prep wrong, the bondwill fail eventually.
Then there are the curingprocesses and potential defects.
If the adhesive isn't mixedcorrectly, if it's past its pot
life, if the temperature orhumidity isn't right during
cure, all these things candrastically reduce the final
(18:11):
bond strength.
And again, these defects mightnot show up immediately, but
lead to premature failure downthe line.
Lucas Adheron (18:16):
So consistency is key.
Eleana Bondwell (18:17):
Paramount.
Long-term durability underenvironmental stress is another
huge factor.
Watch bonds face a tough life.
Extreme temperatures, constantheating and cooling cycles, UV
D-radiation from sunlight,moisture, chemicals from sweat
or the environment, all candegrade the adhesive over time.
It can become brittle, loseadhesion, delaminate, and
(18:40):
there's also long-term creep toconsider where a bond under
constant stress slowly deformspermanently.
Lucas Adheron (18:45):
Right.
It's not just about initialstrength, but strength over
years.
Eleana Bondwell (18:48):
Exactly.
Miniaturization and precisionapplication also pose hurdles.
Applying tiny, precise amountsof adhesive without getting it
where it shouldn't be, withoutdamaging delicate parts, it's
challenging.
There's also the risk,especially in smartwatches, of
outgassing volatile compoundsreleased from the adhesive
during or after cure potentiallycontaminating sensitive
(19:08):
electronics.
Chemical compatibility isvital.
Lucas Adheron (19:11):
And the big one we touched on earlier.
Eleana Bondwell (19:12):
Yes, disassembly and recyclability.
This is a major challenge,starkly highlighted by that
swatch example.
Many high performancestructural adhesives are
designed to be permanent.
That's their strength,literally.
But it makes componentsimpossible to service, as the
source said, or incrediblydifficult to take apart for
repair or recycling withoutcausing damage.
Lucas Adheron (19:33):
So durability clashes with sustainability.
Eleana Bondwell (19:35):
There's a definite tension there, a
tension between achieving theultimate product durability and
robustness through permanentbonds and the growing imperative
for repairability.
for sustainability, for a morecircular economy.
It's a tough balance for theindustry.
Lucas Adheron (19:50):
So to wrap up, adhesives have clearly evolved
way beyond just simple glues.
They're fundamental enablers ofmodern watch design,
performance, manufacturingefficiency.
They're constantly pushing theboundaries in precision and
aesthetics.
They really are the unsungheroes of modern watchmaking.
Eleana Bondwell (20:05):
That's the essence of it, absolutely.
And the science isn't standingstill.
The continued evolution ofadhesive chemistry promises even
further advancements.
offering potential solutions tocurrent challenges, especially
that tricky tension betweenmaking things last forever,
sealed tight, and making themrepairable or recyclable.
It's a fascinating tightropewalk for the industry going
(20:27):
forward.
Lucas Adheron (20:27):
Which leaves us with a final thought for you,
the listener.
If modern watchmakingincreasingly relies on these
maintenance-free designs, oftenenabled by permanent adhesives,
what does this shift from atradition of the repairable
heirloom to potentially moredisposable technology mean for
our understanding ofcraftsmanship, value, and
consumer expectations in thefuture.
What if the true unsung hero of a watch isn't its
intricate gears, its sparklingjewels, or even its precision
movement?
What if it's something youcan't even see?
Something that's fundamentallychanged how they're made and how
we interact with them.
Today, we're talking aboutglue.
Seriously, welcome to the DeepDive.
Get ready to join us as we peelback the layers, pun absolutely
(00:20):
intended, on the hidden worldof adhesives and watchmaking.
We're going to use the materialyou've shared to uncover how
glues, sealants, bonding agents,how they've become utterly
indispensable to moderntimepieces.
We'll trace their journey fromhumble beginnings right up to
some truly cutting-edgeapplications.
Eleana Bondwell (00:36):
Yeah, and what's really fascinating here
is how something so, well,seemingly simple as glue has
profoundly reshaped an industry,an industry long renowned for
its mechanical precision, itsintricate craftsmanship.
It really is a journey fromtraditional artistry to
high-tech manufacturing.
Lucas Adheron (00:53):
Exactly.
And by the end of this deepdive, you'll have a shortcut to
understanding the, let's callthem, sticky secrets of watch
design, a surprising history youprobably never expected, the
diverse chemistries at play, andsome really interesting
trade-offs between durabilityand Well, repairability.
You'll gain a whole newappreciation, I think, for how
the watch on your wrist isactually built.
Okay, let's unpack this then.
(01:15):
Why the shift?
From traditional mechanicalfasteners, screws, and things to
adhesives.
When I think of watches, Iimmediately picture tiny screws,
springs, not screws.
Well, not glue.
What drove that fundamentalchange?
Eleana Bondwell (01:29):
That's a great question, and it really comes
down to a couple of things.
Evolving consumer demand andnew technological capabilities.
People now want watches withthinner profiles, lighter
materials, much better waterresistance, and of course, the
seamless integration of complexelectronics, especially with the
rise of smartwatches.
Mechanical fasteners with theirbulk, their limitations.
(01:50):
They just couldn't keep up withthese demands without
compromising the design orperformance.
Lucas Adheron (01:56):
Right.
They take up space.
Eleana Bondwell (01:57):
Exactly.
And modern adhesives offersolutions that traditional
mechanical fasteners simplycan't.
They enable truly seamlessjoints, provide superior
sealing, better protection fromthe elements.
And crucially, they allowmanufacturers to bond completely
to similar materials.
Think metal to glass or plasticto composite.
You can do that withoutcompromising structural
(02:18):
integrity or adding significantbulk.
Lucas Adheron (02:20):
So it's not just about ditching the screws.
Eleana Bondwell (02:22):
Not at all.
It's about pushing the verylimits of what a watch can be,
how thin, how waterproof, howintegrated it can become.
Adhesives really unlocked anentirely new design language.
They're critical for achievingthe performance, the longevity,
and the sleek aesthetics weexpect today.
Lucas Adheron (02:39):
It's wild to think about how far back this
idea of glue goes, though.
Even before anyone was dreamingof telling time with a tiny
machine on their wrist, thehistory here is far deeper than
I ever imagined.
Eleana Bondwell (02:50):
Oh, it's astounding.
We're talking maybe 200,000years ago, Neanderthals using
birch bark tar.
Lucas Adheron (02:56):
Birch bark tar.
Eleana Bondwell (02:57):
For what?
To haft stone tools, basically,sticking the stone head onto a
handle.
Lucas Adheron (03:02):
Wow.
Eleana Bondwell (03:02):
Then fast forward, you've got ancient
civilizations.
The Egyptians, maybe 1,500 to1,000 BC, using animal glue for
wood bonding.
You can see it into Takamun'scoffin.
And the Romans, the Greeks,they refined animal and fish
glues, even adding things likeegg whites, blood, even cheese,
apparently.
Fish.
Lucas Adheron (03:21):
Seriously.
Eleana Bondwell (03:22):
Seems so.
So the basic idea, theunderstanding of adhesive
properties for precision, fordurability, has been around a
very, very long time.
Long before watchmaking as weknow it.
Lucas Adheron (03:32):
But when did it really make its proper
horological debut?
I'm picturing some old schoolwatchmaker hunched over a bench,
pulling out a pot of...
shellac, was it?
Eleana Bondwell (03:42):
You're absolutely right.
Shellac.
It's a natural polymer actuallysecreted by the lac bug.
It was historically reallysignificant in watchmaking.
It's key property.
It's thermoplastic.
Melts at a relatively lowtemperature, around 75 degrees
C.
Lucas Adheron (03:54):
Okay, so it melts easily.
Why was that useful?
Eleana Bondwell (03:56):
It allowed watchmakers to secure pallets,
those little jewels, on thelever plate.
They could gently heat thelever, soften the shellac, then
make incredibly precise, tinyadjustments to the pallets, and
then just let it cool to harden.
It fixed the jewels first, Ah,I see.
And the
Lucas Adheron (04:18):
crucial point, I guess, was that you could undo
it.
Eleana Bondwell (04:20):
Exactly.
It's reversibility.
You could undo it with heat,which allowed for future repairs
or adjustments.
That was vital for traditionalwatchmaking.
Lucas Adheron (04:27):
So that reversibility was key for
shellac.
Makes you wonder if modernwatchmakers sometimes wish they
had that easy undo button withall the permanent glues we'll
get to.
Eleana Bondwell (04:36):
Huh.
That's a fantastic point.
And yes, it touches on thechallenges we'll discuss later.
But for now, let's move fromancient glues and shellac into
the modern era.
What really kicked off thesynthetic revolution in
watchmaking adhesives?
Lucas Adheron (04:49):
Well, speaking of synthetics, I came across
something called GS Hypo Cement.
That sounds pretty specific.
What made that particularadhesive such a sort of pivotal
moment?
Eleana Bondwell (04:59):
It absolutely was.
GS Hypo Cement, invented backin 1939, was specifically
formulated for watchmaking.
That was the key.
It came with a very fineprecision applicator.
It dried clear, mediumstrength.
Crucially, it wouldn't damagedelicate surfaces like plastic
watch crystals.
So it became ideal for bondingthose plastic glasses, bezels,
little metal parts.
Lucas Adheron (05:20):
And what made it stand out?
Eleana Bondwell (05:21):
What truly distinguished it was its
controlled setting time.
It got tacky and about 10, 15seconds vital for making tiny
adjustments.
Then it dried in maybe 10, 15minutes and was fully hardened
after about an hour.
That controlled timing wasessential for delicate assembly
work.
You had a window to work.
Lucas Adheron (05:38):
Right.
Not instant, but not hourseither.
Eleana Bondwell (05:40):
Precisely.
And soon after, you getcyanoacrylates, what most people
call superglue.
Their introduction offeredextremely rapid bonding, which
opened up even morepossibilities for assembly,
especially for small, quickfixes.
Lucas Adheron (05:52):
This historical overview really sets the stage.
But the real strategic pivot...
The moment glue changed, notjust how watches were made, but
maybe how we think about owningthem.
That seems to be exemplified bythe Swatch Skin family, right?
This wasn't just about making awatch thinner.
It was about rethinking thewhole product lifecycle.
Eleana Bondwell (06:12):
That's absolutely right.
The Swatch Skin family,introduced in 1997, is the
perfect case study here.
In these watches, the movementis permanently sealed inside the
case.
They use a structural adhesivethat secures both the acrylic
crystal on the front and thecase back.
Lucas Adheron (06:27):
Permanently sealed, so you can't get into
Eleana Bondwell (06:28):
it.
Exactly.
The consequence of this designis, as the sources state, the
timepiece becomes invulnerableto environmental conditions,
moisture, dust, whatever.
But the flip side, and this iscrucial, is that they are
rendered maintenance-free, i.e.
impossible to service.
Lucas Adheron (06:43):
Wow.
Impossible to service.
That's a big shift.
Eleana Bondwell (06:46):
It's huge.
The shift fundamentallyprioritized robust sealed units
and frankly, cost effective massproduction over the traditional
model of repairability.
It moved towards products that,while incredibly durable when
sealed, are ultimatelydisposable rather than endlessly
serviceable, at least intheory.
It really redefined productlife cycles within that segment
(07:07):
of the industry, and it changedconsumer expectations for
certain types of watches.
Lucas Adheron (07:11):
And it's fascinating how we still see
that kind of dual approachtoday.
You have these cutting edgesynthetics for mass-produced
sealed units, but traditionalshellac is still being used for
delicate repairs and in high-endartisan craft where
serviceability is paramount.
There's still a balance.
Eleana Bondwell (07:26):
Precisely.
It reflects the diversity ofthe watch world itself.
Lucas Adheron (07:30):
So, okay, we've gone from tar and cheese through
shellac, GS Hypo, super glue,and now this era of
disposability, or at leastnon-serviceability, for some
watches.
Let's dive into the actualchemical arsenal a modern
watchmaker has.
It's not just one kind of glueanymore, is it?
It sounds like a whole paletteof polymers, each tailored for
specific jobs.
Eleana Bondwell (07:48):
That's a great way to put it, a palette.
The industry uses a reallydiverse array of adhesive
chemistries, each picked for itsunique properties and
suitability.
It's like a specializedtoolbox.
Lucas Adheron (07:59):
Okay, so what are the main players in this
toolbox?
Eleana Bondwell (08:01):
Well, first up, you have epoxies.
These are workhorses, widelyused for their high strength,
their durability, and excellentresistance to chemicals and
temperature.
They're typically two-partsystems, you mix them, and a
chemical reaction createsincredibly strong bonds.
Lucas Adheron (08:16):
Where would you use those in a watch?
Eleana Bondwell (08:18):
Crucial for structural bonding.
Think attaching glass orsapphire crystals to metal
cases, bonding metal to metalcomponents.
Sometimes even for settingjewels, though that's often
you've now.
You'll see things likequick-setting five-minute
epoxies for general repair,maybe specific jeweler's epoxies
like Vigors, or evenindustrial-grade ones like
Huntsman's Eroldite 2014-2 forreally demanding applications.
Lucas Adheron (08:42):
Like aerospace-grade stuff, almost.
Eleana Bondwell (08:44):
Pretty much.
Imagine that level ofstructural integrity scaled down
to a tiny component in yourwatch.
That's the kind of bondingwe're talking about.
Then there are silicones.
These are valued for completelydifferent reasons.
Exceptional flexibility, forone.
They also handle a hugetemperature range from cryogenic
right up to high heat and offersuperior moisture resistance.
Lucas Adheron (09:06):
Flexible and resistant.
Sounds good for sealing.
Eleana Bondwell (09:09):
Exactly.
They come in various curingformats.
RTV, room temperaturevulcanizing, is common, means
they cure without needing heat,which is vital around delicate
movements.
Their main job in watchmakingis case sealing, creating those
essential airtight andwaterproof barriers.
Dow's dowsilla adhesives are aprime example known for clarity
(09:29):
and They're the invisibleshields protecting the watch's
heart.
Silicones are also vital insmartwatches for protecting
sensitive electronics, sometimeseven used for damping
vibrations.
Lucas Adheron (09:39):
Right, protecting delicate components, not just
holding them.
Eleana Bondwell (09:42):
Precisely.
Next up, polyurethanes.
These are known for theirtoughness, their impact
resistance, and strong adhesionto lots of different materials.
They can be moisture-curing ortwo-part systems.
In watches, they're used forstructural parts and are
particularly good as waterproofglues for case sealing.
They provide really lastingresults against water exposure.
(10:03):
You might see chemistry similarto what's used in automotive,
like DuPont's BetaSeal, adaptedfor luxury goods where that
robust impact resistance isneeded.
Lucas Adheron (10:12):
Interesting.
And what about the quick stuff,superglue?
Eleana Bondwell (10:14):
Yep, cyanoacrylates are instant
adhesives, still very much used,they cure extremely fast,
right?
Room temperature, strong bondsin seconds, perfect for small,
precise bonding where you needthat immediate tack.
And for high-end goods, they'vedeveloped specialized
low-blooming and low-odorversions.
Avoids that white residue, theblooming you sometimes see,
keeps things looking clean.
Lucas Adheron (10:35):
Ah, good point.
And the last big category.
Eleana Bondwell (10:38):
UV curable adhesives.
These are a really significantadvancement because they offer
amazing control.
They pull Limerize or curerapidly seconds to minutes, but
only when exposed to specificwavelengths of UV light.
Lucas Adheron (10:52):
Cure on demand.
Eleana Bondwell (10:53):
Exactly.
Cure on demand allows forreally precise positioning of
components before you lock themin place.
They often have excellentoptical clarity, which is key.
Primarily used for bondingwatch crystals and glasses to
bezels and cases.
Also very important for pottingor sealing sensitive electronic
parts in smartwatches, wherethat clarity and precise
(11:14):
placement are critical.
Lucas Adheron (11:15):
So it's way more than just the core glues.
Sounds like there's some highlyspecialized solutions, too, for
very specific functions withinthe watch.
Eleana Bondwell (11:21):
Absolutely.
Beyond those main chemistries,watchmaking relies on other
things.
Like thread lockers.
Think Loctite.
These are used to secure tinyscrews and bolts against
vibrations, stopping them fromloosening over time.
Importantly, many formulationsstill allow for normal
disassembly later.
Lucas Adheron (11:36):
So they lock, but not permanently.
Eleana Bondwell (11:38):
Often, yes.
Depends on the grade youchoose.
Then there are dial adhesivesand tapes.
These can be tiny self-adhesivedots or double-sided tapes.
They're used for securing watchdials to the movement,
especially useful if theoriginal dial feet those little
pins that hold the dial getbroken during a repair.
It's a common fix.
Lucas Adheron (11:58):
Ah, practical solution.
Eleana Bondwell (11:59):
And then there's something really
advanced, surface modificationcoatings.
Aculon is a name you mighthear.
Now, crucially, these are notadhesives themselves.
They're nanoscale treatmentsapplied to the surface first.
Lucas Adheron (12:12):
To make the glue stick better?
Eleana Bondwell (12:14):
Essentially, yes.
They work by directlyfunctionalizing the substrate,
chemically altering the surfaceat a nanoscale so the adhesive
can form a much stronger, morereliable bond.
It reduces the chance ofdelamination or failure.
Plus, they can add otherproperties like making the
surface repel water orfingerprints.
It's about optimizing thesurface for the adhesive.
Lucas Adheron (12:33):
That's fascinating.
Really prepping the battlefieldfor the glue.
Eleana Bondwell (12:36):
A good analogy.
It ensures the best Okay,
Lucas Adheron (12:40):
with all these advanced chemistries and balls,
who's actually making thesesuper glues?
And how do they even get intothe hands of a watchmaker?
Are giants like Dow, DuPont,Henkel, and Huntsman just, I
don't know, shipping barrels ofthis stuff directly to
Switzerland?
Eleana Bondwell (12:54):
Well, not directly, usually.
It's more indirect.
These major global chemicalmanufacturers play a crucial
role, but often behind thescenes.
Their huge R&D efforts forreally demanding industries,
electronics, aerospace,automotive, produce
manufacturing, materials thatare directly transferable to
horology, the requirements areoften similar.
Precision, durability,resistance.
Lucas Adheron (13:15):
So the watch industry benefits from R&D done
for other fields.
Eleana Bondwell (13:18):
Absolutely.
For instance, Dow makesDowsolet instant adhesive, noted
for small items like watches,great clarity, works in extreme
environments.
DuPont has innovations instructural adhesives like
urethanes and epoxies used inautomotive, maybe EV battery
sealing chemistries directlyapplicable to strong watch
cases, plus electronic materialslike silicone lid seals.
(13:40):
Henkel, they're the world'sbiggest adhesive provider.
Their Loctite brand iseverywhere in watch repair and
manufacturing.
Thread lockers, retainingcompounds, instant glues, UV
curables, you name it.
Lucas Adheron (13:51):
Loctite, yeah, I know that name.
Eleana Bondwell (13:53):
And Huntsman with their Eroldite brand.
That's high-performanceepoxies, acrylics,
polyurethanes.
Again, often developed fordemanding electronics or
aerospace, needing that precisebonding and extreme durability
perfect for advancedwatchmaking.
The watch industry iseffectively leveraging solutions
developed for otherhigh-precision, high-reliability
fields.
It's a huge advantage.
Lucas Adheron (14:12):
Okay, so the big guys make the base chemicals.
How do they actually get to thewatchmaker's bench?
Eleana Bondwell (14:17):
Right.
It's a sort of multifacetedsupply chain.
On one side, you have largeindustrial distributors.
Bodo Möller Chemie is a goodexample.
They're premier globaldistributors of specialty
chemicals.
They don't just ship boxes.
They offer technicalconsulting.
They have labs for testingapplications.
They provide training.
They might be an authorizedHenkel distributor for example,
(14:39):
they bridge that gap between themassive chemical producers and
the more bespoke needs ofwatchmaking.
Lucas Adheron (14:47):
So they add expertise.
Eleana Bondwell (14:48):
Exactly.
Then on the other side, youhave the niche watch parts
suppliers, companies like PerrinWatch Parts, Time Connection
Inc., Esslinger & Co., GrobitUSA.
These cater directly toindividual watchmakers and
repair professionals.
They stock everything from theclassic GS Hypo Cement and
various Loctite products rightback to traditional pure
shellac.
Ah,
Lucas Adheron (15:09):
so they serve the repair side and smaller makers
more directly.
Eleana Bondwell (15:12):
Precisely.
It's this dual supply chainthat ensures the industry gets
both the cutting-edge industrialsolutions needed for mass
production and the continuity oftraditional materials essential
for the artisanal side, forrepairs, for heritage skills.
Lucas Adheron (15:25):
It's a blended approach, then, giving
watchmakers the best of bothworlds, from, like you said,
space-grade epoxies right downto time-honored shellac.
Eleana Bondwell (15:34):
That captures it perfectly.
Lucas Adheron (15:35):
It sounds like adhesives are truly magical for
watchmaking, then.
Enabling all sorts ofinnovations, unlocking new
designs, cleaner looks, thinnercases.
But there's always a flip side,isn't there?
What are the inherentadvantages clearly laid out and
what are the trade-offs?
Because I imagine as powerfulas these glues are, they must
come with some real challengestoo.
Eleana Bondwell (15:56):
Oh, absolutely.
The upside, the advantages arecompelling.
You hit on some already.
Huge design flexibility andaesthetics.
Cleaner, sleeker looks withoutvisible fasteners.
Thinner, lighter watches becomepossible.
They're fantastic at bonding tosimilar materials, metals,
plastics, glass, composites.
They overcome tricky issueslike differing thermal expansion
(16:16):
rates.
Lucas Adheron (16:16):
Meaning things expanding or shrinking
differently with heat?
Eleana Bondwell (16:19):
Exactly.
That difference can easilycrack a less flexible bond or
stress a mechanical joint.
Adhesives can often accommodatethat better.
Allows for really innovativemulti-material constructions.
They also provide even stressdistribution.
A glued joint spreads the loadover a larger area, unlike a
screw, which which concentratesstress at one point.
(16:39):
This improves strength,reliability, fatigue resistance.
Lucas Adheron (16:43):
Makes sense.
Fewer weak points.
Eleana Bondwell (16:44):
Right.
They also contribute to lightweighting and cost reduction,
replacing heavier metalfasteners, streamlining
manufacturing, reducing partcounts, labor, potentially
production costs.
And critically, they createhermetic seals for environmental
protection, vital for waterresistance, keeping out
moisture, dust, dirt.
And finally, some flexibleadhesives offer excellent
(17:06):
vibration damping.
They absorb Okay, that's
Lucas Adheron (17:11):
a strong list of benefits.
It also sounds too good to betrue.
So what's the biggest headache?
What are the real complexitiesand challenges for a watchmaker
or manufacturer working withthese high-tech glues?
Eleana Bondwell (17:22):
The challenges are significant and shouldn't be
underestimated.
First off, surface preparationand quality control.
This is absolutely critical.
Any tiny bit of impurity,oxidation, grease, or
contaminant on the surface canlead to weak bonds or outright
failure.
You can get defects likekissing bonds where surfaces
touch but don't truly bondchemically or porosity, voids,
(17:46):
tiny air bubbles trapped in theglue line.
Lucas Adheron (17:48):
And these are hard to spot.
Eleana Bondwell (17:50):
Incredibly hard, especially in miniaturized
components.
It demands meticulous cleaningprotocols and rigorous quality
checks.
Get the prep wrong, the bondwill fail eventually.
Then there are the curingprocesses and potential defects.
If the adhesive isn't mixedcorrectly, if it's past its pot
life, if the temperature orhumidity isn't right during
cure, all these things candrastically reduce the final
(18:11):
bond strength.
And again, these defects mightnot show up immediately, but
lead to premature failure downthe line.
Lucas Adheron (18:16):
So consistency is key.
Eleana Bondwell (18:17):
Paramount.
Long-term durability underenvironmental stress is another
huge factor.
Watch bonds face a tough life.
Extreme temperatures, constantheating and cooling cycles, UV
D-radiation from sunlight,moisture, chemicals from sweat
or the environment, all candegrade the adhesive over time.
It can become brittle, loseadhesion, delaminate, and
(18:40):
there's also long-term creep toconsider where a bond under
constant stress slowly deformspermanently.
Lucas Adheron (18:45):
Right.
It's not just about initialstrength, but strength over
years.
Eleana Bondwell (18:48):
Exactly.
Miniaturization and precisionapplication also pose hurdles.
Applying tiny, precise amountsof adhesive without getting it
where it shouldn't be, withoutdamaging delicate parts, it's
challenging.
There's also the risk,especially in smartwatches, of
outgassing volatile compoundsreleased from the adhesive
during or after cure potentiallycontaminating sensitive
(19:08):
electronics.
Chemical compatibility isvital.
Lucas Adheron (19:11):
And the big one we touched on earlier.
Eleana Bondwell (19:12):
Yes, disassembly and recyclability.
This is a major challenge,starkly highlighted by that
swatch example.
Many high performancestructural adhesives are
designed to be permanent.
That's their strength,literally.
But it makes componentsimpossible to service, as the
source said, or incrediblydifficult to take apart for
repair or recycling withoutcausing damage.
Lucas Adheron (19:33):
So durability clashes with sustainability.
Eleana Bondwell (19:35):
There's a definite tension there, a
tension between achieving theultimate product durability and
robustness through permanentbonds and the growing imperative
for repairability.
for sustainability, for a morecircular economy.
It's a tough balance for theindustry.
Lucas Adheron (19:50):
So to wrap up, adhesives have clearly evolved
way beyond just simple glues.
They're fundamental enablers ofmodern watch design,
performance, manufacturingefficiency.
They're constantly pushing theboundaries in precision and
aesthetics.
They really are the unsungheroes of modern watchmaking.
Eleana Bondwell (20:05):
That's the essence of it, absolutely.
And the science isn't standingstill.
The continued evolution ofadhesive chemistry promises even
further advancements.
offering potential solutions tocurrent challenges, especially
that tricky tension betweenmaking things last forever,
sealed tight, and making themrepairable or recyclable.
It's a fascinating tightropewalk for the industry going
(20:27):
forward.
Lucas Adheron (20:27):
Which leaves us with a final thought for you,
the listener.
If modern watchmakingincreasingly relies on these
maintenance-free designs, oftenenabled by permanent adhesives,
what does this shift from atradition of the repairable
heirloom to potentially moredisposable technology mean for
our understanding ofcraftsmanship, value, and
consumer expectations in thefuture.
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