The (Humble) Big Barrel of Water
If you’ve ever visited our factory and watched us blow glass, you might have seen the giant barrel of water next to our shop stations, generally right next to the ‘dummy’ - or the steps from which the blower blows.
A humble piece of equipment, to be sure - just a barrel of water filled up with a hose. But this barrel does a couple of things for us.
First and foremost, it allows us to keep the wooden mould we’re using at the time completely soaked. Why do we keep our cherrywood moulds soaked? So that when the screaming hot glass touches it, it doesn’t just spark a fire and ruin all of our hard work! But even more important than that, on our ‘turn’ moulds – the moulds in which the blower turns or spins the hot glass inside the closed mould – that water in the wood creates a pocket of steam that insulates the wet wood from contact with the hot glass. The glass is, in turn, shaped by the steam that takes the contours of the mould between the glass and the wood.
Secondly, though, it’s an awfully handy barrel of water for crackling glass! If you’re a fan of crackled glass, you may have wondered how it is that we create those fine, delicate cracks on the surface of the glass without cracking the glass all the way through. That may even be the very reason why you like crackled glass – that it reminds us of how delicate the medium is!
In order to get a piece of crackled glass, we blow the hot glass into the mould as we normally do. But then, when we take the glass out of the mould, we plunge it all the way under the water in the barrel. The longer the hot glass piece stays under water, the deeper and more profound the cracks are – but if you dip it in and pull it out really quickly, it takes a fine crackle on the surface of the glass. We run it immediately to the glory hole to reheat the piece, steam off the excess water, and help seal any sharp edges or flaking glass that results from the profound thermal shock of the water barrel.
It does a third service for us, our big barrel of water. It allows us to quickly cool a pipe that has overheated, or, at the end of the shift, allows us to plunge the length of the pipe into the cool water and cool off the pipes enough to clean and store them for the next day’s use!
