Originally Posted by DaveLT
How is 310,000 and 350,000 virtually identical It is a difference of about 11%. It's still comparably weaker. Also acrylic is 342000 to 500000 psi tensile strength roughly around 319000 of PETG and their tensile strength is 7000 to 12100
psi vs 7000-8000 of PETG
Also the reason PETG is easier to bend when heated is that they have a low melting/malforming point. That should have been clear
I am being condescending because most of the points you list are all "upsides" when really they aren't. You seem to put PETG in a better light than it truly deserves.
I once lost a system thanks to PETG tubing
Another word, isn't PET often stained?
I don't mean to put PETG in a better light than it deserves. I was posting my impressions after having worked with it. I will concede that I may have overstated the strength of the material, when what I meant was its tolerance to stress... and yes, it achieves such tolerance from being more malleable. I am going to have to contest some of the numbers you just provided, though.
You wrote "acrylic is 342000 to 500000 psi tensile strength roughly around 319000 of PETG and their tensile strength is 7000 to 12100". I am sorry, but that is incorrect. I think that you meant to write 350,000 to 500,000 tensile modules, not strength. So if we compare apples to apples and oranges to oranges, we will see a different picture:
PETG Tensile Modules (psi) = 320,000
Cast Acrylic Tensile Modules (psi) = 350,000
PETG Tensile Strength (psi) = 7,700
Cast Acrylic Tensile Strength (psi) = 8,038 (I understated this earlier... see, no bias)
PETG Flexular Strength (psi) = 11,200
Cast Acrylic Flexular Strength (psi) = 12,000
So it is true that PETG is not as strong as cast acrylic, but it is very close... and when I say that, I mean that with respect to using it in watercooling loops.
You also write that PETG has a "low" melting/malforming point. Again, I think that you are using the wrong terminology. According to the data, PETG has no definite melting point. It's forming temperature (which is what I think you mean) is 137 C to 160 C. How is this a "low" malformation point in the context of watercooling? Are you running boiling water in your system? I don't think that the cause of the mishap that was linked to earlier (at themodzoo.com) was ever determined... so a low malformation thermal point is not "clear".
Regardless of any of this, you had no reason to be condescending. One of things that I love about pc and tech enthusiasts is that I find them to be altruistic, patient and -- although opinionated -- courteous to each other. If you feel that I am overstating the positives about PETG, then just say so and rebut my assertions. I took time to write my post, and I did so simply with the intention of giving my impressions... I am always looking to learn, so I would've been more receptive if you'd posted your second post the first time. Ya know what I mean.
You say that you lost a system to PETG tubing... what happened??? I have all my tubing runs done and have leak tested, but I haven't filled with coolant and cranked up my system. I think that I'll wait for your response to do so.
Lastly, in response to your staining question... no, PETG does not stain. I do not know about PET, but PETG does not. If there is one thing that I have read repeatedly with regard to PETG virtues, it is that it has "superior chemical resistance" and is less likely to stain than just about any other transparent plastic -- including acrylic (which is not to say that acrylic will stain either).