Interview with a Watchmaker

Lessons in Water Resistance, Shock, & Respectful Restoration from True Patina’s Greg Petronzi, Because You Can’t Use Your Tools if Your Watch Doesn’t Work 

At Watches of Espionage, our ethos is to Use Your Tools, the belief that a meaningful relationship can be developed with watches through shared experience. This lifestyle depends on having a fully functional timepiece, and a commonly overlooked aspect of our appreciation for watches is the community of watchmakers that keep our timepieces fit for duty.

Whether for regular servicing, restoration of a vintage piece, or repair after hard use, something we know many of you are guilty of, watches are tiny, complicated machines requiring maintenance in the skilled hands of trained technicians. In the W.O.E. Community, one of the most trusted names is Greg Petronzi, an experienced watchmaker, the founder of True Patina and TrueDome, and a passionate collector of military watches. 

Greg at the bench at True Patina HQ. (Photo Credit: True Patina)

Over the years, Greg has worked on several of my watches, including my South African-issued Tudor Submariner reference 7016, and he has a keen eye for balancing restoration, originality, and utility. For this Dispatch, we sat down with Greg to learn more about his life and work, as well as to explore some of the most common questions y’all might have for a watchmaker. 

If you’ve seen our video torture testing a Tudor Pelagos FXD with 10,000 rounds of shooting at the hands of GBRS Group, Greg was the watchmaker who did the before and after testing, so we started there… 

Greg was the watchmaker who evaluated the Tudor FXD before and after our 10,000-round stress test. (Photo Credit: Brock Stevens)

Watches of Espionage: Were you surprised by the results of the 10,000-round stress test? 

Greg Petronzi: I was genuinely surprised by the results of the stress test, especially considering some of the higher-powered firearms involved. In my watch repair work, I frequently correct bent hairsprings, so I suspected that repeated recoil might cause mild hairspring distortion. That kind of deformation would typically show up as changes in rate and an increased delta (the spread between the slowest and fastest positions). After 10,000 rounds, and effectively 10,000 recoil shocks, the fact that there was no measurable impact on timing was extremely impressive.

WOE: What could you expect to see from these types of microvibrations?

GP: Outside of hairspring distortion, the other thing we see from frequent vibrational stress would be a loosening of screws. This is often mitigated by keeping high screw torque.

WOE: How did you get into watchmaking? 

GP: It happened by chance. I had been a watch enthusiast for as long as I can remember. However, after finishing my doctoral degree in counseling psychology, I found myself with more time to explore new interests. I befriended a Rolex watchmaker and began learning little by little, eventually establishing an informal apprenticeship with him.

I soon realized I had a natural aptitude for the craft. I started by servicing my own watches, then those of friends, and eventually began receiving requests from people I didn’t know. 

At that point, I recognized the potential to take it seriously as a business. When COVID hit, and lockdowns began, I dedicated a significant amount of time to honing my skills and building my workshop. I started to share some of the work I was doing on Instagram and YouTube, and the business grew organically from there.

WOE: What military-issued watches do you own, and why these specifically?

GP: I currently own a Rolex 5513 SBS MilSub, a Tudor M.N. 76 “Snowflake”, a CWC W10 field watch, a Benrus Type I Class A, and I just purchased a Class II Type B.

Greg’s personal Rolex MilSub reference 5513. (Photo Credit: True Patina)

The Rolex MilSub had always been my grail watch. Beyond its appearance, its history and rarity made it something I was deeply drawn to. After many years of collecting and developing my career, I realized that if I sold off the majority of my collection, I might be able to afford one, so that’s exactly what I did.

A strong example came up at auction, but it wasn’t full spec; it was missing an insert. I knew that would improve my chances of winning. I also felt confident that my connections in the watch world would eventually help me source a correct insert. That turned out to be true much sooner than I expected. I found the insert just a few months after winning the auction and was able to bring the watch to full military specification.

I’ve owned it for several years now, and it remains my favorite watch. Even today, every time I look at it, I still feel incredibly grateful to have it.

Greg’s Tudor Submariner, issued to the Marine Nationale in 1976.

The Tudor M.N.76 is my “beater” military watch, if there is such a thing. I love it and tend to wear it more casually than the MilSub, whether I’m lifting weights or riding my motorcycle. I appreciate that it brings some color to my collection while still carrying the history and provenance of a true military watch.

I believe my first military watch was the CWC W10 field watch. Made for the British Army, it’s a manually wound watch with a cushion case and, at around $600, a very cool entry point into military watches without spending a lot of money.

I owned one years ago, sold it, and eventually found myself buying another. I rarely wear it now, and it sits on my “strap wall” next to my workbench, where it looks pretty cool hanging alongside all the nylon pull-through straps. I still feel like it's one of the coolest military watches for the money.

Greg’s issued Benrus Type I. (Photo Credit: True Patina)

In my opinion, the Benrus Type I Class A is the American MilSub. It’s easily one of my favorite watches. I acquired one long before I ever thought I’d own a MilSub, and to me, in the realm of American military watches, it’s one of, if not the coolest.

I’ve worked on many of them and learned that there’s a specific way to service them to avoid crown stem issues. It’s a very simple watch, yet it can be surprisingly tricky to service if you’re not familiar with those nuances.

I also recently purchased a Type II Class B, which was made for US Navy personnel operating in environments where the use of tritium-based luminescent material, which was mildly radioactive, was prohibited. They are generally believed to have been issued on nuclear submarines. These are very rare watches and very cool given their history and the fact that they were never available to civilians.

The Use Your Tools ethos in action. (Photo Credit: True Patina)

WOE: You have worked on many military-issued vintage pieces. Do you see any difference between these and other vintage pieces?

GP: Yes and no. Many military watches have been worn hard, but so have many civilian watches. I would say there’s a higher probability of finding a vintage military watch that has seen real impact or moisture damage compared to its civilian counterparts. But that said, all watches tell their stories to an extent. What's nice about military watches is that you can sometimes learn about their lives through the wear and any service marks inside the caseback. It's an additional part of the history and provenance that, at least to me, makes them all the more interesting. 

WOE: What are the considerations for restoring a vintage military-issued watch, balancing originality and restoration?

GP: That’s a great question; one that I think aptly applies to any important vintage or historical timepiece. I think whenever possible, it’s helpful to keep the cosmetically visible parts of the watch original. For instance, leave the dial and hands untouched. However, with military watches, often the hands were larger to carry more luminous material for visibility (i.e., sword hands and snowflake hands). These can crack and degrade with time and wear. 

A good practice is to have the original luminous stabilized such that the originality remains intact while preserving the wearability. With regard to the dials, wear takes on different forms with age. Some wear is natural, such as a “tropical” dial turning brown from exposure to the sun. Whereas other issues, such as tool marks from a careless past watchmaker, can be repaired if desired, so long as the dial’s overall originality remains unmolested. This is a more nuanced decision that the owner needs to consider. 

I can certainly understand the argument that some of that wear is part of the watch’s history and therefore should be left alone. I think that's a valid point with military pieces, perhaps even more so than with civilian watches. That said, movement restoration is essential to preserve the watch’s longevity. And in my view, that should be carried out at five to six-year intervals by a qualified and trusted watchmaker. This interval isn’t arbitrary, by the way; that is often the shelf life of even the most advanced fully synthetic oils. Thus, preserving the watch’s mechanical condition is dependent on regularly cleaning and re-lubricating with fresh oils. When properly serviced, good mechanical watches will last for generations. 

WOE: What is the most historically significant piece you’ve handled, and what condition was it in?

A RAN Rolex “Big Crown” Submariner reference 5510 Greg serviced in 2024. (Photo Credit: True Patina)

GP: This is a tough one. I’ve had the privilege of working on so many very important military and civilian watches. I’ve serviced over 15 different MilSubs at this point; the majority of which were complete overhauls. One of the more historically significant of them may have been an Australian-issued 5510 “Big Crown” submariner, one of only four known examples. The watch was written about by Fratello Watches, and we did a video of the overhaul, actually, which was fun to share on YouTube with people.

WOE: You developed TrueDome, a replacement crystal for vintage Rolex and Tudor watches. What is the background there, and why is it generally acceptable to replace the crystal?

(Photo Credit: TrueDome)

GP: Crystals, first and foremost, are a wear item on a watch, much like tires on a car. There’s one key difference, though: crystals also have a significant cosmetic impact on the overall experience of a watch. In the same way that certain vintage cars need “whitewall” tires to complete the look, certain watches benefit from the correct acrylic crystal profile.

TrueDome was my answer to a long-standing deficiency in the vintage Rolex and Tudor community. Many collectors, myself included, revered the original “Superdome,” which was characteristic of earlier acrylic crystals. Over time, that form changed to a flatter, less appealing profile.

The vintage world is often filled with parts claimed to be original that aren’t. I experienced this firsthand when I was scammed into buying what I believed were genuine Superdomes, only to discover they were cheap aftermarket substitutes. And the existing aftermarket options simply weren’t very good; the distortion, proportions, and acrylic quality were all disappointing.

That experience led me to the idea of reverse-engineering the original Superdome and producing a high-quality alternative to vintage acrylic. Now, six years later, I can proudly say there’s a TrueDome on every vintage Rolex I own. I’m equally proud to offer them to my friends and fellow collectors.

A technical drawing from the TrueDome development process. (Photo Credit: TrueDome)

WOE: What are some general considerations for water resistance, and how often should I get my watch tested for water resistance? 

GP: One thing I always emphasize is that water resistance involves far more than just the crystal. It depends on the condition of the gaskets, the integrity of the threads on the mid-case, caseback, and crown, and the contact points between the crystal, rehaut, and retaining ring or bezel. All of these elements work together to maintain a proper hermetic seal.

As a general rule, it’s wise to replace gaskets every five years or so, and the crystal roughly every ten years, just to be safe. Periodic pressure testing is also a good practice, especially if you plan to regularly submerge your watch or wear it in wet conditions.

(Photo Credit: True Patina)

WOE: If I am swimming with my neo-vintage Rolex 16800 Submariner and I notice humidity or water droplets under the crystal, what should I do?

GP: Great question that I often get asked. Regardless of whether this is a neo-vintage, vintage, or brand-new watch, if you see fog under the crystal, there is moisture in your watch case. It could be a little, it could be a lot. My advice is to pull the crown out and place it under a hair dryer on medium heat, one foot away. Blow-dry until the moisture disappears. This may need to be repeated a couple of times. Then, place the watch in a bed of dry rice and ship it to your watchmaker immediately. If you can open the case back, do so in a dry, dust-proof container, then send it to a watchmaker. The longer moisture stays inside a watch case, the more damage it does to the movement parts as well as the dial and hands.

WOE: What are some of the risks of magnetism for mechanical watches? How can I tell if my watch has been magnetized, and can it be fixed? 

GP: Magnetism often happens from airport scanners, placing a watch on top of cell phones, wireless chargers, or loudspeakers. A magnetized watch will most often run faster. But they can also run slower or just erratically. Demagnetizing is very easy with the proper equipment and not nearly as bad for a watch as moisture damage.

A MiSub on a modern Phoenix strap. (Photo Credit: True Patina)

WOE: You recently became an authorized dealer for Phoenix straps. For the uninitiated, what is the history of Phoenix, and why are they important in the vintage watch space?

GP: Yes, this was very exciting for me as a MilSub enthusiast. Phoenix straps were issued on MilSubs as the official supplier to the British MOD, producing NA TO-style straps. They have always been made in the U.K.

A few years ago, Mike, the owner of Phoenix, closed the business after many years of running the company. Recently, he decided to reopen and collaborate with a small group to bring them back in limited batches. They actually reached out to me to see if I’d be interested in collaborating, and I was thrilled by the opportunity.

I’m thrilled to offer them for sale to fellow fixed-bar enthusiasts.

To learn more about Greg's work, check out True Patina and TrueDome. 

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