I have been printing with PETG on glass for a little while now, and have gone through almost an entire roll. Yesterday I had my first print stick so hard that it delaminated the glass :(. I stopped using hairspray as it made the prints not stick at all, and printing bare glass was just fine. But something about yesterdays print made the glass give up. Is this how PETG + Glass normally fails? Works perfectly for years, and then suddenly fails?
Just clean it with alcohol (IPA), dishwasher fluid or glasses cleaner spray
I had just cleaned it with methylated spirits before the print that killed the bed :(
Windex and gluestick are other options besides hairspray. And yes, you experience is not uncommon.
Never tried Windex, but might give that a go. Gluestick had the same issue, lots of prints wouldn’t actually stick so I had lots of failures :/ I vaguely remember someone suggesting sugar water, so might try that as well.
Windex to clean, let it dry for a bit, then a layer of gluestick has always worked for me, as long as the bed heats to 60°C for printing. The z offset has to be a bit different for PETG than PLA, which can be a bit tricky. I think (been a whole since I’ve printed PETG) it had to be a bit higher than PLA, so it wouldn’t “squish” as much as PLA. Seemed a bit counterintuitive, but it solved most of my problems
This does happen.
+1 for glue stick.
Also a layer of blue painters tape works well for me.
Another thing I’ve had good success with is cleaning the bed well with 95% IPA (thanks resin printing!) Then dropping the build plate with print attached into the freezer for a bit after it’s done.
I used to do tape, but i really like the smooth finish that bare glass gives. Glue stick gave me bed adhesion issues, and i cant easily remove the glass bed.
I think the glass delaminated while it was cooling normally, not when i was prying it off.
You might look into a smooth build plate. It can take the damage and just be replaced.
I went with glass originally as it seemed at the time to be durable and therefore less waste. I don’t want to generate extra waste. And those pei sheets dont look cheap :/
Thanks for the suggestion though, will keep it in mind
I don’t tend to print on glass, but this failure mode isn’t surprising - repeated heating and cooling, plus the mechanical stress of the PETG slightly contracting as it cools will create microscopic cracks the build over time until the sheet fails
Yup, in hindsight that seems obvious. But i never had super strong adhesion to begin with, so I assumed it was fine. And my impression was that petg glass failures were something that happened instantly, rather than a gradual thing.
Maker’s Muse recently recommended G10 garolite as a durable print surface. This is basically a sheet of fiberglass fabric embedded in epoxy resin. It’s cheap material, highly heat resistant and apparently releases prints very well.
I watched that video when it came out, but never made the connection to that being useful to me. I might give that a go when my replacement glass bed fails. Thanks!
