Bottom falling out of mugs!

[smiley_mug]

I buy the European mugs from printerowners as they are supposed to be the best, but twice now I've had customers come back and say the base of the mug has come off. It is like someone has sliced through the mug just above the base and it seems like the crack appears when it is first filled with hot water. No injuries but obviously a safety issue. Has anyone else had this or could it be something I'm doing wrong? I reported it to the sales people the first time and they said it was a one in 500,000 chance but looking more like a 1 in 500 chance to me.

[GoonerGary]

I've read Amazon reviews of sublimation mugs with this happening. It happened to me too years ago on the odd occasion. When pressing, you might hear a ping. That is a hairline crack forming. I'm guessing that too much pressure in the press along with a manufacturing fault is to blame.

[Justin]

How do you cool your mugs after printing out of interest?

My suggestion would be to try other mugs. I only use Xpres XP5013 mugs, never had a damaged or defective mug in last several years. Tried another well know supplier recently and I had over 20 damages in a 300 mug run, yellow staining, very poor indeed.

[smiley_mug]

Thanks GoonerGary I have heard pings in the past but not sure if they relate to this mugs, do you suggest binning if you've heard a ping or maybe testing with boiling water to see if it's caused a crack? I will try reducing my pressure too if poss without effecting prints.

Thanks Justin I could try switching supplier and I just allow the mugs to air cool afterwards sitting on a wooden bench.

[manic]

I had this a couple of time years ago (This was when I used water to cool mugs) , doesn't happen or should I say it hasn't happened since I air cooled them.

[GoonerGary]

The ping or dull sounding crack is the sound of the mug fracturing. By coincidence I had one yesterday for the first time in years and sure enough, there was a barely visible hairline crack. It was caused by too much pressure of the heat blanket due to a warping of the mug at the base, so loosen it slightly for that one mug. The heat blanket should hug round the mug a little.

Not all mugs are 100% straight and require small adjustment in the press, but some mugs are much straighter than others. Definitely bin it, don't bother with a boiling water test.