PETG not sticking to PEI bed  

RE: PETG not sticking to PEI bed

Dawn and water scrub PEI surfaces whenever swapping between PLA and PETG. Their print residues are mutually incompatible and not removable with just alcohol.

RE: PETG not sticking to PEI bed

I print directly on smooth PEI sheet with Isopropyl wipe down before each print. The trick is to allow the bed to completely cool before removing the parts. I have pulled some PEI off my sheet when trying to pull parts off while it's still hot, but when the bed is cool they pop right off. 

RE: PETG not sticking to PEI bed

Posted by: @guy-k2

Dawn and water scrub PEI surfaces whenever swapping between PLA and PETG. Their print residues are mutually incompatible and not removable with just alcohol.

On one printer, I have have a tough time with the first layer.  I am going to have to try soap and water.  

RE: PETG not sticking to PEI bed

How did you calibrate your first layer? Hard to beat Live Z.

RE: PETG not sticking to PEI bed

409 is NOT Window Cleaner.  Entirely different formulations.

Try real Windex brand.  Wash the sheet with soap and water, rinse in hot water for a long time (minutes) to remove all soap and oil residues; then spritz lightly with Windex, and using a fresh paper towel wipe the Windex around so it evenly coats the sheet, then let the Windex dry as a film.

Also - some PETG (Amazon that I've tried) wants a clean sheet to stick well.  Other PETG (Prusa) wants Windex or it sticks like super glue. No two brands of PETG are the same.

RE: PETG not sticking to PEI bed

Also keep in mind - some PETG sticks too well. It can rip off the PEI layer.

Nothing beats the textured sheet for PETG. Well that is my opinion. I won't let PETG touch my smooth sheet.

RE: PETG not sticking to PEI bed

Posted by: @tim-m30

409 is NOT Window Cleaner.  Entirely different formulations.

Try real Windex brand.  Wash the sheet with soap and water, rinse in hot water for a long time (minutes) to remove all soap and oil residues; then spritz lightly with Windex, and using a fresh paper towel wipe the Windex around so it evenly coats the sheet, then let the Windex dry as a film.

Also - some PETG (Amazon that I've tried) wants a clean sheet to stick well.  Other PETG (Prusa) wants Windex or it sticks like super glue. No two brands of PETG are the same.

This is true.  One of my smooth sheets PEI sheets is pretty scarred from PETG.   

RE: PETG not sticking to PEI bed

Thanks for all your input.  Here's an update.  Long story short, when I washed my PEI sheet with dish-washing fluid and water and then dried it at 100C on the printer bed, PETG started sticking like a champ.  Prior to that I also tried doing just an IPA clean as brandon-r9 suggested and it stuck better (enough for me to do a print), but I saw some peeling on small features.  I didn't have any trouble peeling it when the bed was cool.

So, dishwashing soap and hot water clean seems to be the winner, although it is somewhat more of pain to do before each print than just wiping with IPA...

RE: PETG not sticking to PEI bed

Washing with Dawn is an occasional thing. Not after every print!

Do it maybe monthly, to get the scum off.

IPA wipe as needed, after every print or so.

We are preaching the Religion of Dawn - just don't over-do it.

RE: PETG not sticking to PEI bed

I will have to try Dawn.  Thanks.  I used to use it, but quite after to Prusa instructions were released.  

RE: PETG not sticking to PEI bed

Washing with Dawn is an occasional thing. Not after every print!

Sorry, I didn't mean to imply after every print. Like Rob said, it is an occasional thing.

When you change filament types, wash with Dawn. Maybe once a month just for gradual grime buildup.

Otherwise, just IPA wipe between prints. Actually, often I don't even wipe with IPA. Pop off the parts cold and avoid touching the plate surface with fingers. I use a chef's knife to flip the skirt free. 

RE: PETG not sticking to PEI bed

I'd use Dawn-and-wash every day if the sink were convenient. Certainly not every print, but regularly. A bottle of isopropyl alcohol is just a lot more convenient. 

RE: PETG not sticking to PEI bed

@bobstro

Great. So sounds like most of you had no issues of TOO much adhesion using an IPA wipe.  I’ll probably continue with occasional dish soap washes and IPA before each print. 

RE: PETG not sticking to PEI bed

If you are using PETG on the smooth sheet - keep the Windex handy. Sooner or later - you will need it.

RE: PETG not sticking to PEI bed

Can I just make a shout out for Double-sided Textured PEI Powder-coated Spring Steel Sheet .

I went through two smooth PET sheets before I tried the textured and I haven't looked back.

well worth the money.

RE: PETG not sticking to PEI bed

@julian-b10

It has it place as does my old smooth pei.  

RE: PETG not sticking to PEI bed

As for cleaning with alcohol, I've pretty much stopped using it.  It generally makes adhesion worse.  And I only use 91% poured directly from the bottle on to the bed.  Now when soap and water fail to restore the surface I go straight to acetone, then do a wash and dry to rinse off what the acetone picks up. 

RE: PETG not sticking to PEI bed

Posted by: @tim-m30

As for cleaning with alcohol, I've pretty much stopped using it.  It generally makes adhesion worse.  And I only use 91% poured directly from the bottle on to the bed.  Now when soap and water fail to restore the surface I go straight to acetone, then do a wash and dry to rinse off what the acetone picks up. 

That is very much contrary to most of what other experience.

RE: PETG not sticking to PEI bed

I found PLA followed by PETG is a disaster waiting to happen.

The sugars release during PLA printing do not wipe off using IPA, and it takes either a hot soapy wash with water to clean or, a 1 layer PETG print to basically stick to the sugary deposits and peel them off with the PETG, and even then it does not guarantee full removal.

Your best bet is to have separate plates for  PLA and PETG. Smooth PEI for PLA and the textured sheet for PETG.