TLDR at bottom -

Have an order due of 2.5g Iranian from one vendor and 1g hong Kong shit. So ordered 4 new oil burners off amazon.

Tried them today with a 0.2 sample I got delivered and ones cracked... The stems heat up ALOT when heats applied to the bubble, there's a creaking sound coming from one or more when it's very hot, one changed shape when I was trying to heat clean it, the bowls looked thick but cracked back and burned wayyy too fast ruining the first bowl.. Then when I get it sorted next bowl.. The heat distribution is fucked.. One spots hot, one spots cold.. I'm doing my usual rotation speed, even heating I'm pretty good at.. But this pipes fucked. Must be shitty cheap glass.. But they looked good on amazon, good reviews... Absolute shit. Worst bowls I've used by far.

TLDR - amazon burners are absolute shit, cheap Chinese glass... Where in the UK is best for buying oil burners?

I'm not sure if this counts as sourcing... Paraphanelia is 100% legal in the UK so....?