DSF

Hi everyone,

When I remove the mug from my press, I can hear a little crack sound. The mug stays intact but I can see some blue shadowed lines inside it. Again, no breaks, no visible cracks, just those lines. I'm attaching some photos.

Do you know if it's a weird behaviour and what could be causing it?

Which mugs are you using? What press/time/temp etc?

Hi Justin,

AA grade orca coated mugs, 200 °C 201 seconds, high pressure... Press is a Chinese multipress

Hi, temp is a bit high and time is a bit long in my opinion. I use Orca mugs at 175-180c for 180 seconds. Although I have never been able to crack a mug as such through increased temp / time. Only other thing I would suggest is to ensure the mug is warmed before inserting into the press, this reduces a sudden change in temperature which can cause hairline cracks.

Alex

.... And remember you don't need a very high pressure, as long as blanket is making good contact with mug all the way around, it should close with just a little force.

Those lines are cracks. Did you sort it? if so what was it?

as already said Warm the bottom of the mug before pressing, Try reducing the temp and time. I use a chinese 5 mug press, temp is 170c for 160 seconds.