Glass presses - Which to buy?

Greetings! 

You will not see a lot of video on mantamods about glass removal or fitting - indeed if you want to see that, you need to go to the refurb of the CWC Navy Diver which had an acrylic glass that had been scratched to near opaqueness over its life up to the point of refurbishment. 

Why is that? Largely because mod cases are sold with the glass pre fitted and it seems sensible to run with that given the lack of clear specifications around size of apertures and potential for tolerances to be out etc when purchasing. Don’t get me wrong, there are plenty of good sellers providing clear and accurate dimension specifications with consistent quality on Ali that allows for this, but you’ll need to be deep into your Ali sellers curation journey to get this right. 

I suppose it’s just easier to go with a pre-fitted glass but its also more expensive to fit yourself as there is little to be saved buying a case without glass fitted, and adding an AR coated glass is so much more expensive as to give pause for thought in value (or profit if you’re making to sell) terms in the context of a build - probably adding 25% to the total cost of a standard NH36 build. 

Anyway, if you are determined to do your own thing with glass, then which glass press should you buy? Pressing a glass into a watch (much more so than pressing it out) is a game that requires a good deal of ‘feel’. In the way that a steering wheel of a car gives you feedback as to the road surface and grip, a good glass press is one which allows you to feel the amount of pressure being applied. 

The first glass press that I bought had a screw-press mechanism where I would wind pressure onto the glass with a turning knob - that was absolutely numb and I smashed the old glass in the CWC whilst removing it - probably more to do with the die that I was pressing the glass out into being too small, but nevertheless I had no clue as to the amount of pressure I was applying as I had no feedback from the machine and it was probably immense to have smashed the glass as thoroughly as it did. (Sadly, I did not film that happening at the time as I’d got a ‘wrap’ on removal as I’d heard the glass pop out and stopped filming, only to find it needed a bit extra to complete the job and did not restart the camera for this). 

So the antidote to the very poor screw down mechanism is a lever mechanism. So buy a lever press, defo, as a lever gives you the feedback and pressure control that you want, but you also need (a) substance and (b) distance when making your choice of press as there are plenty of options out there:

(a) Substance is about size and weight - you want a machine that is planted and will not become unstable as you assert your own pressure to it. So heft and a wide base are things to look for (albeit you can always screw a wider wood base onto a smaller machine to give it stability).

(b) Distance is about the gap between the crucible in which the watch case will sit and the side of the housing of the mechanism. If this is not very wide, then you will have trouble turning the watch case in the die as you apply pressure to fit a new glass, as this turning motion seems essential to me, to ensure that pressure gets applied evenly as you push the glass so and you don’t angle the glass in and stretch / trap any gasket awkwardly, and / or leave the glass unevenly seated in the case.

If you follow that guidance you will narrow the available field considerably, but it’s also important to remember the ‘buy cheap, buy twice’ mantra at this point so as you don’t compromise through frugality. I think that of all of the tools in a modder’s arsenal, this is the one where you really cannot get something cheap but functional. Anything under about £60 is too cheap and will be crap. The Swiss made ones can be £500, which is nonsense for a Seiko modder, but there are copies on Ali which are just as good at a price either side of £100. 

I suppose as a one-job tool (albeit in refurb mode, these presses can also be used to remove and insert the housings for crowns and chrono buttons), the need to buy something of a specific quality and price puts a question mark over the efficacy of messing about with glass at all, but that’s all choice and this article is designed to assist in making that choice…

So, as ever, bon chance my friends. 

Here’s a couple of examples of good presses: one is >£100 and one is <£100