Hi Everyone . Hope you all are well. Little question for anyone who does mugs here. When you are doing a big order of mugs
do you
1 put your mugs in a bucket of water to cool quickly?
2 Wait for them to cool naturally.?
The reason i am asking these questions is because i have been told by a well respected member of our local community not to water cool them as it interfers with the cooling of the mug leaving transfers open to degredation. I did have to take his advice afterall because he worked for a well known pottery most of his life. What do you guys think?
Cool them everytime. If you leave them to cool naturally then there is a danger that the image will blur a little. The ceramic mug is VERY hot and at 180 degrees C the sublimation inks are still in their gaseous state. Cooling them rapidly reduces the heat in the mug and stops the inks from blending. The cooling process could, for example, be boiling water - not necessarily cold water - as this will still reduce the heat of the mug dramatically. Obviously don't use boiling water and be aware that cheap mugs might crack in cold water straight from the mug press, so to be on the safe side use tepid water. It will soon heat up once a dozen or so mugs have been dunked in the water.
I rarely dip if I don't have to. After you get used to lots of different designs you get to have an idea of what might bleed if left to cool naturally. Dipping is a pain on big orders as water tends to get everywhere and slows packing down.
In the days of TAMS, I dunked all the time without issue. Since then, you can never be sure how the mugs will stand up to the sudden drop in temperature. After all, there is a difference between a 10oz RN-coated mug and soft-coated colour-change mug. The old white-panel black mugs would never tolerate dunking without pinging (and if they ping, you're in trouble), and I wouldn't want to dunk that heat-sink of a mug, the 15oz El Grande or the barrel steins.
These days I cool with a desk fan. I set the fan at the end of the table and, as the mugs come out, I line them up to cool - moving each line back when fresh mugs come out of the oven/press. By the time the table is full, the first ones are cold and ready to box.
If I'm in a rush, I up the fan to its faster setting.
Remember that you only have to get the mug to drop below about 140C to prevent further sublimation, and the temperature will drop quicker at the beginning than at the end. If you're using a press rather than an oven, the inside of the mug and the handle won't be that hot anyway - so the first step in cooling down is handled already. You don't need to shock-cool them from burning hot to freezing cold.
(sorry, private joke everyone else 
)