[Closed] Printing PETG kills my PEI Sheet  

Re: Printing PETG kills my PEI Sheet

From the PDF manual:

PETG sticks very well to PEI, which is generally a good thing. But sometimes it could stick a
little bit too well and you could rip a piece of PEI from the bed, so you should use a
separating​​agent​(e.g. gluestick).

So yeah, RTFM 🙂

Re: Printing PETG kills my PEI Sheet

With my mks2 every print went off with the gluestick 😂

Re: Printing PETG kills my PEI Sheet

Also suggested by PRUSA is using window cleaner to clean the PEI sheet before printing PETG. The residue left by the detergents act as a sufficient separating agent. When I use Windex before printing PETG, it comes off the sheet as easily as PLA. I've yet to need to use the glue stick.

Re: Printing PETG kills my PEI Sheet

I've also had luck with the Windex solution (ptp)

Re: Printing PETG kills my PEI Sheet

Before the Mk3 I used the same sheet of 0.03" PEI for over a year while exclusively printing PETG without any issues.

Less than a month of use on the Mk3 and both sheets of PEI have begun developing stress cracks, usually at the corners of larger objects. I think the PEI being used it far too thin to hold up to long term usage.

Re: Printing PETG kills my PEI Sheet

Been printing almost exclusively PETG for months and using genuine Windex for bed cleaning. Works fine, never had to use glue stick.

Re: Printing PETG kills my PEI Sheet

Any ordinary windows cleaner will work - I use a environmental friendly windows cleaner for a year now with no problems.
I think it is the thin soap film left behind that helps PETG slipping the PEI sheet.

If you have a sticking PETG part, warming up heat bed to 40C will help - In some cases applying alcohol to the edge between part and bed will make it slip.

Re: Printing PETG kills my PEI Sheet

I'm just getting started with PETG. Absent contamination of the print surface (from finger oils, etc.) do you need to wipe with Windex before every print to protect the PEI?

Re: Printing PETG kills my PEI Sheet

I'm just getting started with PETG. Absent contamination of the print surface (from finger oils, etc.) do you need to wipe with Windex before every print to protect the PEI?

No. I add either Windex and Glue Stick prior to all pETG prints to prevent over adhesion.

Re: Printing PETG kills my PEI Sheet

thanks!

Re: Printing PETG kills my PEI Sheet

I printed PETG with both standard heated bed (PEI directly on heated bed) and new steel sheets. Sure removing print from steel sheets is much more easier. Manipulation with spatula could have damaged the bed. Now the bed looks like new in the print area for an year.
I can see one weaknes of steel sheet. For me it seems, that the PEI sheet is not holding there as strong as it was on the bed directly. For the printing area I have no issues. However the starting line, which is every time on the same place and with quite big amount of filament and also some times without Z calibrated perfectly (because this you do just after that) damaged my PEI sheet. It started with small peace ripped off the bed, but after that it continues. So currently this part of steel plate is completely without PEI. I do use this side still for PETG printing and the second side for PLA.

Milos

Re: Printing PETG kills my PEI Sheet

So you print directly on the steel sheet with PEI when printing PETG?

Re: Printing PETG kills my PEI Sheet

Almost yes, but just the front left corner piece for the initial line. Because there is a "hole" inside, it does not stick so well and therefor I can still remove it after print. Looks ugly, but I will replace both PEI in the same time finally, not just the one (or maybe I will replace the whole sheet, time is money 🙂
But the point was, that the PEI is not holding very good on the steel sheet.

Re: Printing PETG kills my PEI Sheet

Otherwise, printing PETG directly to the PEI steel sheet is without issues, just clean it with IPA and than make it a bit dirty with Windex or similar.

Re: Printing PETG kills my PEI Sheet

Otherwise, printing PETG directly to the PEI steel sheet is without issues, just clean it with IPA and than make it a bit dirty with Windex or similar.

Thanks. I may transition to a naked steel sheet for PETG.

Re: Printing PETG kills my PEI Sheet

Not sure what you mean by naked steel sheet 🙂 Sure PEI has to be there.

Re: Printing PETG kills my PEI Sheet

For this initial line, it does not matter much. But for the print area itself, sure it matters. Bad is that even a small hole in the PEI will lead to bigger ones later 🙁

Re: Printing PETG kills my PEI Sheet

Sure removing print from steel sheets is much more easier.

This created the confusion. sort of no mention of PEI.

Re: Printing PETG kills my PEI Sheet

I will continue to use Windex.