PETG eats the glassbed, what to do? Sometimes when I print with PETG it takes a chunk out of my glassbed, why does it do that, how to prevent it? I print the part and when it is finished I let it cool off, usually it just pops of the bed, but sometimes it takes a piece of my borosilicate glassbed with it. I'm not applying force or anything, the glasschunk is just sitting underneath the part I just printed when I lift it off, still stuck to the part and impossible to get loose. I print with the bed at 70C for the first few layers then 65C. https://reprap.org/forum/read.php?262,554321,554321#msg-554321 Tue, 12 May 2026 03:13:10 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?262,554321,834056#msg-834056 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,834056#msg-834056
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dlc60
Wow, this just never happens. I wonder where our processes differ?
DLC

Very easy thing.
Tape and hair-spray protect your glass from PETG bits it.
If you don't use tape or hair-spray, you realize PETG doesn't need it to stick on glass.
But realize it's too hard to remove from glass.
After realize too sticky PETG, don't try to remove by scraper or pull/push PETG from glass.
If you do, you find PETG eats the glass.
Only need is wash by water gently, and wait PETG spit glass!]]> YMita Printing Wed, 19 Sep 2018 10:20:14 -0400 https://reprap.org/forum/read.php?262,554321,833003#msg-833003 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,833003#msg-833003 I get the best results with plain glass with hair spray. I let the surface cool and the part just pops off.
I have used MakerGeek PETG, eSun PETG and Sunlu PETG, all with the same results. No glass chipping.
Same with ABS prints, I have less time with ABS, but still quite a few prints. Both small and large parts.
This is on four different printers as well.

Wow, this just never happens. I wonder where our processes differ?

DLC]]> dlc60 Printing Thu, 06 Sep 2018 12:50:10 -0400 https://reprap.org/forum/read.php?262,554321,832485#msg-832485 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,832485#msg-832485 If you use BOROSILICATE GLASS bed, only gently wash under the water after cool down.
It't too easy to remove, no need of scraper or another tool, or stick glue, tapes. Only pick and pull by your finger!]]> YMita Printing Fri, 31 Aug 2018 07:19:43 -0400 https://reprap.org/forum/read.php?262,554321,806401#msg-806401 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,806401#msg-806401 I am printing on Glass with kapton tape on it an di do not have an problems with removing the print from it.]]> Tessanger Printing Sat, 20 Jan 2018 05:26:51 -0500 https://reprap.org/forum/read.php?262,554321,806366#msg-806366 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,806366#msg-806366 Roger123D Printing Fri, 19 Jan 2018 21:08:21 -0500 https://reprap.org/forum/read.php?262,554321,804417#msg-804417 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,804417#msg-804417 forums.reprap.org]. Oh, and I do things like this too [www.youtube.com]]]> deckingman Printing Mon, 08 Jan 2018 04:42:53 -0500 https://reprap.org/forum/read.php?262,554321,804416#msg-804416 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,804416#msg-804416
KEEP THE GLASS CLEAN!

When first going for PETg, it seemed to me that either the objects do not stick at all, or they will stick so well that it's hard to remove. If the bed was not hot enough (70C), or the leveling was incorrect, there was no adhesion. Increasing the temperature to 75C, the printed objects got stuck for good. With larger (about 20cm) objects the loss was was 1 glass / 1 object. The glasses were normal 2mm "photo frame" glass from two different and well reputable local sources. One of the sources advertises supplying Pilkington brand.

The solution was to use clean the glass bed perfectly: no fingerprints, no signs of grease, nothing, just plain shining clean glass, clean as a camera lens. And voila, the problem was gone! Adhesion depends now nicely on bed temperature, which I have set to 73C.

The filament I use is Real Filament PETg. The cleaning stuff is normal alcohol-based window cleaner, which leaves some residues to be removed with a clean napkin.

Hope this helps.]]> willeo Printing Mon, 08 Jan 2018 04:13:06 -0500 https://reprap.org/forum/read.php?262,554321,692334#msg-692334 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,692334#msg-692334 the_digital_dentist Printing Thu, 28 Jul 2016 06:55:29 -0400 https://reprap.org/forum/read.php?262,554321,692330#msg-692330 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,692330#msg-692330 deaconfrost Printing Thu, 28 Jul 2016 06:49:14 -0400 https://reprap.org/forum/read.php?262,554321,692221#msg-692221 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,692221#msg-692221
Edit: The glass screen protectors might be sacrificial, but I have not had any luck getting the PETG to actually stick to them yet. Probably as someone said, the finger print coating is getting in the way.]]> PDBeal Printing Wed, 27 Jul 2016 18:42:25 -0400 https://reprap.org/forum/read.php?262,554321,692216#msg-692216 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,692216#msg-692216 MrBaz Printing Wed, 27 Jul 2016 18:20:32 -0400 https://reprap.org/forum/read.php?262,554321,691920#msg-691920 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,691920#msg-691920 deaconfrost Printing Tue, 26 Jul 2016 20:42:10 -0400 https://reprap.org/forum/read.php?262,554321,691277#msg-691277 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,691277#msg-691277
Regarding screen protectors, they may have an oliophobic coatings to prevent fingerprints and smudges which may interfere with print adhesion.]]> the_digital_dentist Printing Sat, 23 Jul 2016 22:25:37 -0400 https://reprap.org/forum/read.php?262,554321,691260#msg-691260 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,691260#msg-691260 IMBoring25 Printing Sat, 23 Jul 2016 17:28:31 -0400 https://reprap.org/forum/read.php?262,554321,691238#msg-691238 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,691238#msg-691238 article sounds interesting. At least I found it worth a shot for $12 and ordered a glass screen protector from Amazon. Shame I can't get the exact glass size, but got one close enough to try with PETG and hopefully it won't eat the glass bed.]]> PDBeal Printing Sat, 23 Jul 2016 15:24:17 -0400 https://reprap.org/forum/read.php?262,554321,691180#msg-691180 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,691180#msg-691180
I'm wondering if I'm getting chips coming out of my glass because it has been scratched up a lot. Maybe I should consider the printing surface a consumable and start buying a couple replacements.]]> MrBaz Printing Sat, 23 Jul 2016 10:11:01 -0400 https://reprap.org/forum/read.php?262,554321,691001#msg-691001 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,691001#msg-691001
Motedis warns against using PET-G on glass "as it will chip it".. if you bother to view their video.. their text says a generic "pritn on glass.
[www.motedis.com]

Also a thread here on Ultimaker fora:
[ultimaker.com]

I have had several plates ruined by various types of materials.. only when I used hairspray though.. so I no longer use that. Happened on all sorts of different types of glass, and also high quality Boro glass.]]> dintid Printing Fri, 22 Jul 2016 10:36:10 -0400 https://reprap.org/forum/read.php?262,554321,577166#msg-577166 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,577166#msg-577166 deaconfrost Printing Thu, 29 Oct 2015 14:36:54 -0400 https://reprap.org/forum/read.php?262,554321,571893#msg-571893 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,571893#msg-571893
If the glass just pops out, it sounds like you have bad glass, so maybe replace that with nicer glass or a sheet of aluminum. Then put on glue stick, blue tape, or hairspray -- or PEI, if you want to do that.]]> epicepee Printing Sat, 17 Oct 2015 15:14:51 -0400 https://reprap.org/forum/read.php?262,554321,554519#msg-554519 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,554519#msg-554519 Paul Wanamaker Printing Sun, 06 Sep 2015 02:40:11 -0400 https://reprap.org/forum/read.php?262,554321,554403#msg-554403 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,554403#msg-554403
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Dirty Steve
It happens when you have scratches in your glass. The heating/cooling stresses the glass at a scratch, and a print over that scratch can break out chips. I've had ABS do the same thing.

Must be bad quality of the china-glass then, first time it happened the glass was fairly new, had printed some PLA on it and no nozzle crashes or the like had happened.
It happened a couple of times on and off, just moved the "print" to another area.
Today it happened once and the glass was now so damaged so I turned it around and the first print on that side took a really big bite out of it, hence this thread.

Since it had happened before, I had already ordered a spare.
I hope this brittish glass is of better quality then.]]> Koenig Printing Sat, 05 Sep 2015 15:32:55 -0400 https://reprap.org/forum/read.php?262,554321,554376#msg-554376 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,554376#msg-554376 Dirty Steve Printing Sat, 05 Sep 2015 14:41:52 -0400 https://reprap.org/forum/read.php?262,554321,554343#msg-554343 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,554343#msg-554343
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dc42
If you have an aluminium heat spreader under the glass, then you can use ordinary float glass instead of borosilicate (I also know of people who use float glass without a heat spreader, although I wouldn't recommend it). I don't know whether you would have any less problems with chips sticking to the print from float glass than borosilicate, but at least it's cheaper to replace.

Think I will go for that the next go around!

Is this something common, I've not seen anything about it before, I'm new to this so what I have seen is very limited, I was thinking bad quality glass first, came from china.

Now I put on a brand new borosilicate from UK, we'll se how that goes.]]> Koenig Printing Sat, 05 Sep 2015 13:45:59 -0400 https://reprap.org/forum/read.php?262,554321,554331#msg-554331 Re: PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,554331#msg-554331 dc42 Printing Sat, 05 Sep 2015 13:36:04 -0400 https://reprap.org/forum/read.php?262,554321,554321#msg-554321 PETG eats the glassbed, what to do? https://reprap.org/forum/read.php?262,554321,554321#msg-554321
I print the part and when it is finished I let it cool off, usually it just pops of the bed, but sometimes it takes a piece of my borosilicate glassbed with it.

I'm not applying force or anything, the glasschunk is just sitting underneath the part I just printed when I lift it off, still stuck to the part and impossible to get loose.

I print with the bed at 70C for the first few layers then 65C.]]> Koenig Printing Sat, 05 Sep 2015 13:22:41 -0400