CR-6 SE glass build plate - no lifting possible I've been dealing with 3D printing for 1.5 years, but now own a CR-6 SE myself since the beginning of 2021. Most things are already quite clear but for 2 days I have had a problem with the adhesion of the prints.
Nearly all prints I have done so far used the filament shipped with the printer (PLA 1.75) and they came off the building plate after some cooling time by themselves. I used the default printer settings for PLA: 200 °C nozzle temperature, 60 °C printing bed.
Then 2 days ago the prints began to not stick to the bed anymore and I thought this could be because of dust and from touching the bed. So I cleaned the bed with IPA. The microfiber towel was yellowish afterward - so I thought that this must have been printing residues. Since then every print is kind of &quot;welded&quot; to the bed. There is no chance of loosening it without more IPA or way too much force.
I already tried:

cleaning the bed with clean water - unfortunately, didn't work
setting the Z-offset from 0.1 back to 0.2 mm - also no success

Today I also tried a spool of brand new PETG, with the following recommended settings: 240 °C nozzle temperature, 80 °C print bed - but the problem stayed the same.
Am I doing something wrong? Did I destroy the &quot;Carborundum&quot; coating (silicon carbide) of the glass plate?
I have had similar issues, and I have learned three tricks:

Some slicers (i.e. Cura) let you specify the height of your first layer, and I have found that slowly incrementing up from 0.16 mm by 0.2 mm to find the sweet spot of adhesion without warping. Every brand/type is different. But, usually, for me, fall between 0.18-0.22 mm.

Blue painters tape. If you don't need the glass flat finish of printing directly to glass, I always use blue tape. It makes for great adhesion, and also easy removal of super stuck prints, and you can just peel it off the build plate. With blue tape, I tend to add 2-3 °C to the bed temp.

Glue sticks (instead of hairspray). But, Elmer's glue sticks that go on purple and dry clear. When you use these, if a print is stuck, you just need to spritz some water around the print. The print and the glue will wick the water under the print, and reconstitute the glue. Once the glue is tacky again, the print will pop right off. The only downside is a slight texture to the print and not glossy glass flat.


The reason I like the colored glue, as it reconstitutes it activates the cobalt chloride and turns purple again. This is great for knowing when it is good to start printing again. And also tends to become less of a sticky mess than hairspray.