PEI Sheet Bubbling/Damage
Did I do something wrong?
Is this PEI sheet defective?
My printer and PEI sheet only have 16d of print time total, only a fraction of that was using PETG.
https://photos.app.goo.gl/Hc1rZpyZ9eNmsJF98
RE: PEI Sheet Bubbling/Damage
I see it is the smooth PEI hot bed - printing PETG on this will stick too much. I use a wipe with diluted disk wash between print to prevent too much adhesion. This is not necessary with the textured surface.
Have bobbles all the time as I print mostly with PETG. Think it has to do with the higher bed temperature and the small shrinkage of the PETG when it cools down (seen the same with nylon, ABS and PC). Most of the bobbles disappears again with time.
If you print the same model at the same spot multiple times, the bobbles will get worse as they form at the corners and edges of the model.
Have a look at my models on Printables.com 😉
RE: PEI Sheet Bubbling/Damage
The glue delams from the PEI and steel sheets and leaves bubbles. Use a better release agent on the sheet to make removal of PETG a bit easier. Many of us spray Windex on the sheet, brush to spread it evenly and let it dry as a film.
The bubbles will be reabsorbed in time. Sometimes it helps to flip the sheet so the bubbles are down during printing. But the effect -- while disconcerting -- is normal and expected. Also - keep in mind Prusa will tell you the print sheets are disposable - and these cosmetic things are not cause for warranty.