PETG Strength Problems. Layers Adhering

[QuadView]

I have 3 colors of PETG and so far from what I can tell the Clear is by far the best. Has a lot of give to it and doesn’t want to crack. The black and green I have seems brittle.

[curious aardvark]

sounds about right.

[airscapes]

Have a roll of eSun white coming today as this is my first try and PETG.. will see how it goes

[Jester, Jr.]

Since there was a lot of information flowing in this thread and some of what I was doing wasn't correct or incorrect I'll reiterate what I think were the main problems.

NUMBER 1 First layer. Absolutely important that the first layer goes down correctly. I always thought after a few lines I was good to go and leave it be. NO! You much use glue, painter's tape or whatever you find that makes PETG stick to the bed and use it. Then you have to watch the entire first layer go down. Once that's done, you might have to have the first layer go down slow like 10mm/s, you can leave it. Then it's all about fan speed. I don't go over 20% fan speed now.

[airscapes]

I would assume you have all seen this.. it has been around for a while now, was originally posted on the MakerGear forum..
https://www.xyzfabs.com/forums/topic...lack-filament/

Jester, this speaks to what you are saying
Single most important thing with this filament is the calibration – it needs enough room to lay down the thread without brushing the previous layer. Any brushing at all of the prior layer and you get stringy threads that build up on the nozzle and then can dump in a glob later in your print, leave little zits all over the place, or give the print a rough, matte, almost glittery surface, especially on curved areas. The filament almost likes to “air print” by just a tiny bit. If you are getting a lot of buildup on the nozzle, move the first layer away from the nozzle by adding +0.02 mm increments to the Z-Offset in the G-Code section of S3D, until it quits. You do not smash this filament down to make it stick.