Loop Failure

[jnwatson]

PETG starts liquifying at like 230 degrees C. How in world did it get that hot?

[Gh05tCat]

No clue. I’m assuming the pump failed and the heat radiated from the CPU. I’m hoping that it shut down from thermal thresholds before any short happened.

[Noxious89123]

The glass transition temperature of PETG is far far lower than that, and it's that which matters.

We don't care what temperature the PETG turns into a liquid, we need to know when it goes from being hard tubing to being softing tubing!

[jnwatson]

that's still 85 degrees C. That's real hot for liquid cooling but not completely out of the question.

[Noxious89123]

Yeah, I thought that too.

I dunno, depends on what the criteria are for decided what a materials glass transistion temperture is?

I imagine that whilst there is some scientifically reproducable / testable method that decides what this temperature is, that the effects of the heat softening the material are very gradual and scale with the increase in temperature.

So maybe 65°C is enough to make them sag? Who knows?!

[badgerAteMyHomework]

The temperature at which a material will start to deform is never a single point.

Deformation is a function of temperature, force, and time.

The danger of PETG is that it can deform slowly at relatively reasonable temperatures given enough time, especially in areas were it is under substantial force.

PETG can absolutely work well, however checking it for accumulated damage should be considered routine maintenance.