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Mini steel sheet PEI coating is not as good as the MK3S  

Trusted Member
Mini steel sheet PEI coating is not as good as the MK3S

One of the things I notice very quickly after starting to use my new Mini is that the PEI coating on the steel sheet is not the same as the coating on the one that came with the MK3S that I've had for nearly a year. The coating on the Mini is noticeably softer and easier to damage. I routinely end up using a putty knife to carefully pop stubborn items off the bed of the MK3S. I don't have to do that all of the time but once in a while I need to use it to persuade a skirt to leave the premises. I have never damaged the PEI coating on the MK3S when doing this. The PEI looks pretty much just the way it came out of the box. But, on the Mini I have some minor scratches from using the same procedure. They are just barely noticeable but they are definitely from using the putty knife. I've since stopped using the putty knife on the Mini and have resorted to using my fingernail which seems to work and does not leave any noticeable scratches. I could probable find a thin, flexible plastic putty knife that would work but didn't take that step.

I understand that Prusa is using multiple sources for the coating but I would have thought the quality of the coating would be the same. Maybe this is one place they chose to save a bit of production costs for the Mini.

Posted : 30/03/2020 7:25 pm
Prominent Member
RE: Mini steel sheet PEI coating is not as good as the MK3S

Curious question - why do you use putty knife to pry printed parts off? Do you use some glue or hair spray that it holds too much? I just put whole sheet off, leave it cool down and prints partially release on their own. If I am impatient I bend sheet in and out and they pop out completely. 

Posted : 03/04/2020 5:33 pm