PEI Sheet Replacement - Best Technique?

Hi all, well love my Taz, having built an enclosure for it, brilliant prints almost every time.

But for the second time, I need to replace my PEI sheet due to bubbling.

So the first time i did it, I peeled the old one off (was a bit of a struggle) , used alcohol to clean of the glue then fitted the new sheet. It was reasonable successful but I was wondering if anyone has come up with better ways?

  1. I have read putting the bed in the freezer first for an hour make sit easier to remove the old sheet is that correct?

  2. Last time using the alcohol it was still a real pain in the butt to get rid of all the glue, is there a better solvent or technique to use?

  3. When refitting the sheet it was hard to get all the air out, are there any tips on how to do this the best way?

Thanks in advance for any tips or tricks.

Well having done this more than a few times myself, I have a few tips.

  1. Yes, do pop the bed in the freezer for about an hour. The old PEI will come right off.

  2. I wouldn’t use any solvent other than alcohol. You don’t want anything that could possibly leak onto the heater underneath the glass and cause any problems there. Use alcohol and a scraper that has a razor blade or utility blade to remove the glue. It’s messy and a pain, but it’s the safest way to go.

  3. When putting on the new sheet, don’t pull all of the plastic cover off the adhesive. Just peel up some plastic on one edge and position the PEI sheet on one edge of the cleaned glass. Get that edge down while bending the rest of the sheet up a little and start pressing or using something like a ruler to squeegee the air out. Peel a little more plastic off as you go and press more air out. Keep the unstuck PEI flexed up away from the bed as you go and work down a few inches at a time. Make sure you get as much air as you can before pressing the few inches of PEI down. Think of it as almost rolling it down like a carpet, but you want all the air out before it completely laid down.

  4. When it comes time to replace it again, consider going with a thicker PEI sheet. The last time I changed my PEI, I decided to try a 40 mil sheet and I’ve been real happy with it. So far no bubbling and it is much tougher than the original PEI. Of course you will have to compensate for the increased bed height, depending on how thick the PEI is.

http://catalog.cshyde.com/viewitems/3d-printing-materials/ultem-pei

I made a guide video on how to replace your PEI sheet. I did it with the Lulzbot Mini bed, but the process is exactly the same for the TAZ.

https://www.youtube.com/watch?v=Oo4oy7ZJobU&t=389s

-Jim

Thanks for the tips, much appreciated!!

It’s honestly not too bad. Some additional tips:

  • the freezer approach works like a champ.

  • watch a video. I didn’t. I struggled with removing the glue. Seeing others techniques though kind of made me feel stupid (they had a much easier time)

  • be patient when putting the new sheet down. I was left with a few (not terrible) bubbles and know this is going to spell trouble quickly. I will likely need to repeat the process soon. So far haven’t been an issue but bubbles are all sorts of bad (mess with bed adhesion, part removal, print accuracy, etc).

  • alcohol recommended on video above works well. I’ve seen others recommend something like Goo Gone too. The video used a spray bottle. Another nice tip that I could have used going in :wink:. Obvious in hindsight.

Good luck!

A brand new razor blade is key. Stay away from the edges of the glass until you have all the middle cleaned off, or you will wreck the blade. Keep transferring the glue to a paper towel, it will be like a booger you can’t get rid of. Isopropyl alcohol works very well. Do the job on a towel, covered with paper towels.