need to re-coat both sides of two of my smooth PEI steel sheets  

RE: need to re-coat both sides of two of my smooth PEI steel sheets

Posted by: @bobstro

I can't bring myself to throw the old one away. So there it will sit, looking at me with those sorrowful eyes.

Ah yes, it is a difficult thing to throw away something you know you can fix, as you take it to the bin it calls out "I can be like new again, save me!".  So it goes back on the shelf or in the drawer, only to wait and cry out the same thing again someday....  😆 

RE: need to re-coat both sides of two of my smooth PEI steel sheets

I may be way off, but would it work to go over the surface with a 4-600grit sandpaper to smooth it over and just reapply the new surface on top?

Especially if the new surface is abit thicker?

RE: need to re-coat both sides of two of my smooth PEI steel sheets

If you are at whits end and considering the trash, try a splash of acetone.  I pour one one ml of acetone and spread it around with a paper towel.  I wipe if off immediately and then wash the bed with IPA.  For me, it has stored the bed's stickiness and if it ruins it, who cares because I was tossing it anyway.  To me, it resets the PEI.  It has been 100% successful on 4 old beds.  I am about to treat 2 of them again after 6 months of reset.  

RE: need to re-coat both sides of two of my smooth PEI steel sheets

Posted by: @mrstoned

I may be way off, but would it work to go over the surface with a 4-600grit sandpaper to smooth it over and just reapply the new surface on top?

Especially if the new surface is abit thicker?

I have seen suggestions to fill the gaps in a torn PEI surface with gluestick. I did patch my hole temporarily with a cutout of blue painter's tape. Applying a fresh PEI surface over that might work, but I think you'd be risking a new sheet to save an hour's work.

RE: need to re-coat both sides of two of my smooth PEI steel sheets

Posted by: @mrstoned

I may be way off, but would it work to go over the surface with a 4-600grit sandpaper to smooth it over and just reapply the new surface on top?

Especially if the new surface is abit thicker?

  If you mean putting a 2nd PEI sheet over a damaged one, the issue there is the PINDA probe.  You'll end up with 2 layers of PEI and 2 layers of adhesive, that may put the print surface too far away from the steel for the PINDA to sense it.

 I agree on the acetone treatment, only reason to throw away a PEI sheet is physical damage, acetone will rejuvenate it's stickiness very well.

Each acetone treatment makes the PEI a little more brittle and prone to damage, so it is best to only use it as a last resort.

RE: need to re-coat both sides of two of my smooth PEI steel sheets

Posted by: @martys

Posted by: @mrstoned

I may be way off, but would it work to go over the surface with a 4-600grit sandpaper to smooth it over and just reapply the new surface on top?

Especially if the new surface is abit thicker?

  If you mean putting a 2nd PEI sheet over a damaged one, the issue there is the PINDA probe.  You'll end up with 2 layers of PEI and 2 layers of adhesive, that may put the print surface too far away from the steel for the PINDA to sense it.

 I agree on the acetone treatment, only reason to throw away a PEI sheet is physical damage, acetone will rejuvenate it's stickiness very well.

Each acetone treatment makes the PEI a little more brittle and prone to damage, so it is best to only use it as a last resort.

Yes, given that most have offsetvalues in the -0.5 to -1 a 0.1 or 0.2 pei sheet wouldnt make much difference?

A recycling tip (in progress)

Posted by: @martys

Posted by: @bobstro

I can't bring myself to throw the old one away. So there it will sit, looking at me with those sorrowful eyes.

Ah yes, it is a difficult thing to throw away something you know you can fix, as you take it to the bin it calls out "I can be like new again, save me!".  So it goes back on the shelf or in the drawer, only to wait and cry out the same thing again someday....  😆 

I know I'm not printing nearly as much as everyone else here, but in the year I've had my Mini, both sides of the smooth sheet suffered enough relatively minor indignities that I decided to get a replacement along with a Prusament order....and test an alternate method of stripping the old plate.

I didn't want to roll the dice on a random limonene-containing product, so I'm trying Goo Gone Pro-Power; the nice thing about my idea is that this is the only extra purchase. 

In a nutshell, put 2 or 3oz of the Goo Gone and the damaged plate in an empty ziplock bag from a filament spool.  Carefully purge as much air/bubbles as you can from the bag and seal it.  Fold the bag over top of the plate, and lay it flat where it will be undisturbed for a long while.  (you want the whole plate soaking as evenly as possible, so don't hang the bag or have the plate stand on-edge!)

My old plate has been sitting undisturbed this way for around 10 days and it seems to be working.  With only only 3-4 days of soaking and without removing the plate from the bag, I was able to lift the PEI corners and edges a bit.  I'll probably attempt a removal this weekend; I also have a small jug of EvapoRust in case of corrosion...

I did the lemonene bit and it was quick

Goo gone - that's pretty powerful stuff.  Anyhoo, I did the PEI sheet replacement on one of my sheets and used the limonene approach - following prusa's instruction.  Until the PEI sheets are off, not sure what your goo gone is gonna accomplish.  Using the deep freeze approach, the PEI sheets came off in seconds.  Then I soaked them in limonene for twenty minutes and used a spatula to remove the goo.  Getting the sheet clean and the residue gone took less than 20 minutes and I had bare metal sheet.  No corrosion.  Installed the smooth sheets as directed - mine came out with tiny little bubbles under the PEI, but that was more from unsteady hands more than anything else.  I've been using the repaired sheet for a few months now - works fine.

RE: need to re-coat both sides of two of my smooth PEI steel sheets

Little dumb question... i changed both pei sides after quite a few years of hard work and, messed up the new sheet badly with a huge abs print (my bad). I have spare pei to change the damaged side but, after reading the tutorial (even if they say several times that you can change only one side) i have serious doubts about the limonene process. I guess that when you try to dissolve the glue in one side it would affect the other side too, right? I would like to avoid changing both pei sheets as one of them is literally new. I would love to hear what do you think about it, any advice would be much appreciated 🙂