Printing with Bambu Orange PETG and using a gold PEI plate, the bottom surface has this film or discoloration to it. I print a ton of PETG and I’ve never seen this with any other filament. I do like this shade of orange and would like to use it but I cannot have surfaces coming out like this. I’ve tried wiping with IPA and it doesn’t wipe off. Light sanding doesn’t help either. Any ideas?
Edit: Adding another photo of a second set of knobs printed right after with Eryone PETG which comes out normal just like several other brands.
Did you use glue on your build plate at any point in the past?
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Nope. It’s very odd but it’s only the Bambu filament that does this. Added another photo showing a set of knobs printed right after the set with the issues and they came out fine. Also did a set right before with no issues either.
Must be some “doping” of the filament, maybe something to make it flow better to support the printer’s higher print speeds…
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Could be. Only shows in the first layer though. Then again, first layer is slower than the rest. You’d think this would have been noticed by BL in testing. Maybe I just have a bad roll but don’t want to dig into other rolls just to test.
First layer is the only layer with an exposed flat surface from contact with the build plate. If there’s something volatile, it’ll maybe cook off every where else, but be trapped between the print and build plate so it shows up there.
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Yeah, that’s a good point too. Kind of why I posted here because if it was a common thing then others would have seen it I’d think. I did open a case as well to see what BL says. If I get a chance I’ll also pull out an engineering plate and see what it does on that.
Finally heard back from Bambu with no real help. They suggested I hit the discoloration with heat which worked fine for a rebust part but if this was thinner I wouldn’t like the idea of having to “burn” off the discoloration. Only other suggestion from them was to let the plate cool fully which is no help at all.
Brake parts cleaner or acetone on a q tip takes it off for me.
Interesting. So you see it at least so it’s not just me. I tried IPA but not Acetone. I’ll try that. What color did you see it in?
On black PETG-CF using the gold sheet.
I use small lighter to heat up the surface and it is back to normal color
I have the same thing happening with matte black PLA and for the life of me can’t figure out why its doing this.
In my experience, this was evidence of a dirty build plate. Residue left by past prints.
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Nah, it’s definitely the Bambu filaments. Happens with PETG, ABS and even PLA a little. But I can print the same model on the same plate without cleaning switching back and forth between brands and only Bambu stuff does it.
I don’t know what it is but if you don’t let the plate completely cool to where the part basically comes off itself, you’ll have this residue with Bambu filament. I don’t know if it’s some additive to encourage adhesion or to promote release when cooling but it’s only present in BL filaments.
I am not discounting your experience. I was simply stating that when I have experienced this it was an indication that my build plate needed to be cleaned.
I just printed a couple batches of Bambu Metal PLA. I didn’t wait for the plate to cool, and forced them off, but I do not have a residue on them. Again, this is just my experience moments ago.
If there is an additive like you suggest, it could be micro cracks in the filament as it is forcibly removed from the plate. If letting the print cool and come off on its own resolves the issue.
I also remember something like that when I used to print with glue on the plate. That was one reason I don’t use glue anymore, I didn’t like the residue it left on the bottom on the build.
