Glass Build Plate issues

[Ishy 8]

Just removed a large CPE part from the printer and left it for 30 minutes during which time there was a lot of creaking. The part came off with almost no help at all along with the surface of the glass as you can see in the pic. No glue was used on the build plate. Anyone else had this?

[geert_2 560]

This is fairly common with polyesters (PET, CPE,...). Some people advise to use glue, in the hope that the glue layer will break instead of the glass. But for me that didn't help, my glue was too good. So, just like you, I also heard the glass cracking while it was still cooling down.

 

Now I use my "salt method": wipe the glass with a tissue moistened with salt water prior to printing, which leaves a thin almost invisible layer of salt stuck to the glass. For PLA the salt method greatly increases bonding (compared to printing on bare glass) when the glass is hot, but there is no bonding at all when cold. But for PET the salt method slightly reduces bonding, so the glass doesn't crack anymore. Now the model separates from the glass in the salt layer, as desired. Disadvantage is a bit more risk of warping, so I print with no cooling fans. I only use glue now if I need a lot of cooling fan for printing overhangs.

 

[Ishy 8]

Ok, thank's for the reply. Funnily enough I do normally use some hairspray type glue.