I used too much and cracked my glass bed! The part I was trying to pry off had a large surface area. I would not recommend using gluestick and PET tape, from experience. I have heard okay things about ABS/Acetone solution, but my concern is: I don’t want to deal with Acetone. So, I had to figure out how to make PEI work for me, and it’s way better once you convert your process a little.
@PEI 1/8in thick.
I’ve found PEI amber glossy finish to be the superior material. FYI, I’m printing ABS at 85F on the bed. It is possible that 1/8in is too thick, if you have the glossy amber material. The 0.063 amber glossy sheet I am using is the ‘amber glossy’ on both sides sheet. I also order the ‘natural finish’ and it DOES NOT WORK, fyi! Do not buy the ‘natural finish’ PEI. I also used gluestick on the natural finish with no luck. I absolutely could not get it to stick to that surface. Even though the surface appears ‘sanded’ in texture the high glossy amber finish is amazingly superior (contrary to what you would think).
I’ve also been doing this over the past few weeks. And as you described there is a natural ‘bow’ to the sheet. So, if the bow goes face down on the glass and you pull the edges down it works excellent. However, if you do it the other way it will distort the bottom of your print.
Also, because of the heat diffusion on the 0.063 PEI amber sheet that is bulldog binder clipped to the top of my glass bed, I had to disconnect the print fan on the extruder, so that my small parts would not ‘pop up’ or ‘curl’ off the bed. Also, disconnecting the print fan dramatically improved the quality of all the prints on top of the 0.063 PEI amber sheet that is just clamped to the print bed. I now get all perfectly level prints which pop right off when you bend the sheet.
Another thing… if the bed is too hot:
When you flex the PEI sheet, be sure to look at the bow after you flex it. I have found that when my thick PEI sheet heats up the bow can reverse when you flex it while hot. So be sure that you’re placing the sheet bow down when you go to replace it. Also, applying the PEI sheet while the glass bed is still hot will cause the bow to increase. I have found for best results to let the bed cool to below 35F before reapplying the sheet.
And the edges of the bed:
On my printer, the best print seems to be in the center of the print bed. The edges of the 0.063 cool too quickly and I can get parts that pop off or have flaws and unevenness. I’m currently blaming this on the thickness of the PEI and the lack of an enclosure around the heat bed. The temperature of my house can fluctuate over night and this maybe the source of most of my 6+ hour print issues.
I have another 0.040 PEI amber sheet on the way. My hope is that it will solve all my probs(?).