So when we decided it was high time we designed and made our own glass many questions came up before we embarked on the process.
Here we try to answer the commonly asked questions when we make our glass designs.
• What are the raw materials required to make glass?
There are many glass types but the raw material in all glass is Silica, Soda Ash and Lime
• Can any sand be used to make a glass?
Only fine Silica Sand is used in glass production to give it it’s clarity. Did you know that the purest white sand found in Scotland is at the bottom of loch Maree in the West Cost of Scotland's Highlands
• Are there different types of glass?
The make up of the glass determines it’s use, for example crystal used to have a heavy lead oxide content or metal compound, Soda Lime glass melts quicker, but is also a softer glass and is used mainstream glassware too or jewellery making, our glass we use is borosilicate which is tough and strong and is commonly known like Pyrex.
• What type of glass is required for a drinks/whisky tumbler?
Drinking glass tends to be a mix of sodalime glass, crystal. Any glasses with lead content cannot with stand high temperatures so hence why it is more expensive to produce and delicate.
THE PROCESS
Let's take you through the process of making a whisky/drinks tumbler from start to finish.
It is very difficult to talk you through the process unless you visit our studio, we also have many tricks and techniques which glassblowers like to keep as their trade secrets a bit like chefs and their recipes
But basically, the glass is molten on a tube or putty, it is melted to 2000 degrees and the glassblower has to keep turning it to form a ball of hot molten glass. He must turn it to defy gravity and stop it dropping to the floor. It is then blown into a precast mould made from either clay Silica mould or hard metal such as brass this gives it its form. If this was to be free blown and not moulded it would be spun out, and there would be tools such as grabs and mandrils to form the drinking cup. In our case we use a mould, and it is then the cup is reheated to add the solid base to the bottom of the glass.
The whole glass then has to be placed in an annealing kiln for about 12- 14 hours this allows the glass to reach and constant temperature Normally sits at 700 degrees and so it doesn’t cool to quickly and crack.
• What are the moulds used to shape the glass made from?
Generally stainless steel or brass – Carbon graphite mould we use too in some of our designs.
These moulds are bespoke to each product.
There has to be a design concept, initially then sampling would involve initial moulds, once a mould is cast that’s it , if you have to make changes you have to re make a mould, so the designing and sizing is the key part.
From then you make a finished sample and produce a prototype and if the mould and design are what you want then you start producing more of them. It’s sounds simple but it can generally take 6 – 9 months to get projects such as new glassware off the production line.
We deal with small runs but many large glass manufacturers only deal in high volumes so your initial glass run could be around 20,000 units.
• How many times can we reuse a mould?
Once cast it should last around 3-5 years
• How do we decide the weight of the glass – do you do any consumer research into this?
For us it was about the weight and feel in our hand and having worked with many other brands of glassware we knew what was right. From a tumbler to a copita they all have different athestics and weight plays a large part of that. We chose a heavy base which sits ideally in your hand, smooth and robust.
• What trials do we do to put the prototype through before you are happy with the product and launch it?
Quality testing and consumer feedback are the only tests we do, obviously flaws and weakness are usually picked up in first sample runs and can be improved on. Our customers are King so if things don't work for them we listen and make changes.
• What is the most exciting part of the glass making process?
The most exciting thing is seeing molten glass become a “thing” one minute you have a tube in your hands the next you have a glass or a dropper or unicorn! It is also the best feeling it seeing it on a shelf in a store. knowing you have had some input into making it and then getting it into that store.
• If there was a dream product that we could create from glass? what would it be?
I’d love to me able to make larger pieces like stills, we are a small studio so size of items constraints us to smaller products, I’d love to large installations as well as practical pieces. I’d love to make the inside of a whisky column still to show what happens to the liquid inside. Glass stills instead of Copper ... is that too controversial?
• Has glass blowing industry been affected by the development of technology? Is there still a craft element?
Glassblowing is a skill and most certainly has to have the human element. We have seen the very first Glass 3D printers emerge, but these were art spun pieces and although very beautiful I do not think an alternative to the heart and sole of two hands creating pure unique forms.
Our products are made by hand it is the legacy we want to pass on to other glassmakers and keep lampworking and Scottish glassmaking especially very much alive.
So now you know the thoughts the process and the time needed to make your own whisky glass.
Our glassblowers are magicians in their field and creating something that has never been made before is a challenge they relish.