PC killed my textured sheet - calib square won't come off
 
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hawai
(@hawai)
Estimable Member
PC killed my textured sheet - calib square won't come off

Hi everybody,

 

my first interaction with the infamous Prusament PC-Blend got me into big trouble.

I set out to print a calibration square 70x70mm 1 layer thick and have probably started a wee bit too low. The square is now firmly glued to the sheet and even the highly praised and liberally applied kores glue wasn't enough to prevent this.

 

Does anybody have any suggestions how to get this stuff unstuck apart from a good scraping with steel wool and hope that the coating will survive this?

 

As always thanks in advance for the help.

Cheers

Hansjoerg

Posted : 02/04/2021 7:06 am
Peter M
(@peter-m)
Noble Member
RE: PC killed my textured sheet - calib square won't come off

Try putting in a freezer.

I have a chisel  for this( never use this normally), but it will damage your steel plate if it is bonded to much to the bed.

This post was modified 4 months ago by Peter M
Posted : 02/04/2021 9:33 am
herbert
(@herbert)
Trusted Member
RE: PC killed my textured sheet - calib square won't come off

Try putting it in the freezer, perhaps you have luck. Would be the only thing I would try in your situation. Prusa sends a GlueStick with a PC Prusament for a reason 😉 so perhaps it is also a learned lesson for not reading.

Print sheet preparation

Prusament PC Blend can be printed on both smooth and textured print sheets. However, spreading a separating agent on the sheet before you start printing is required. Otherwise, the adhesion of the print may be too strong. The easiest way to prepare your print sheet is to apply a thin layer of paper glue onto the sheet. This is why we include a paper glue stick (KORES) with every PC Blend spool, free of charge. Failing to add a separating layer may lead to damage to your print sheet! While our documentation states that it’s not necessary to apply glue to the powder-coated textured print sheet, the PC Blend is an exception. Do not use the glue when printing with other materials (PLA, PETG, ASA, Flex and others)!

Posted : 02/04/2021 9:36 am
hawai
(@hawai)
Estimable Member
Topic starter answered:
RE: PC killed my textured sheet - calib square won't come off
Posted by: @herbert

Try putting it in the freezer, perhaps you have luck. Would be the only thing I would try in your situation. Prusa sends a GlueStick with a PC Prusament for a reason 😉 so perhaps it is also a learned lesson for not reading.

Oh, you're talking about the Kores glue stick that I have generously applied to the sheet?

Reading the posts before answering is generally quite helpful and it avoids coming across as condescending.

jm0.02$

Posted : 02/04/2021 10:44 am
herbert
(@herbert)
Trusted Member
RE: PC killed my textured sheet - calib square won't come off

Right, should take my own advices in consideration too 🙂 , but because I printed nearly a kilo of PC filament already with glue (in my case UHU stick) applied and had no issues releasing it, my head filtered out this information completely.

 

My fault, and I am sorry for this misunderstanding.

 

Posted : 02/04/2021 11:21 am
hawai
(@hawai)
Estimable Member
Topic starter answered:
RE: PC killed my textured sheet - calib square won't come off

@herbert

No problem, I was just a wee bit miffed that you referenced all the stuff I had just read before I started with the PC filament.

 

The sheet is definitely a goner. Freezing didn't work and neither did trying to scrape the plastic off with a blade. Was completely my own fault for having started the calibration way too low. It just annoys me that I didn't order a replacement sheet with the last order from Prusa. Shipments take ages from Prague to New Zealand...

Posted : 02/04/2021 12:07 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: PC killed my textured sheet - calib square won't come off

@hawai

One thing I would have added to the Prusa instructions for PC blend - start a little higher on Z offset when calibrating the first layer and slowly ease into the right Z.  You are not the first nor the last to make this mistake.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 02/04/2021 12:51 pm
RedDawg
(@reddawg)
Estimable Member
RE: PC killed my textured sheet - calib square won't come off

Worth a try: Under settings, find what the Z offset value is. Add maybe 0.4mm to it. Overprint the current print with the same geometry @ 100% fill at least 10 deg hotter than "normal". Let it print at least 2mm thick. With any luck, the "new" structure will bond to the troublesome layer and they can both be removed together.

1. "Creativity is the sudden cessation of stupidity." and "Any problem can be solved with the materials in the room." -Edwin Land, inventor of the Polaroid Land Camera. 2. "If I can't fix it, it isn't broken." -Me....
Posted : 02/04/2021 1:34 pm
Daryl
(@daryl-2)
Trusted Member
RE: PC killed my textured sheet - calib square won't come off

Freeze spray might be helpful if applied just to the printed part, causing it to shrink and release.  Depending on bond surface coating might come with it.

Posted : 02/04/2021 3:33 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: PC killed my textured sheet - calib square won't come off

The bond can be very tight.  I have had print warp and bow the sheet.

--------------------
Chuck H
3D Printer Review Blog...
Posted : 02/04/2021 5:32 pm
3Delight
(@3delight)
Moderator
RE: PC killed my textured sheet - calib square won't come off

I have absolutely no experience with PC Blend but... what about if you heated the bed as hot as possible to try to soften the bottom most layer and flex the sheet while at full temp (wearing gloves of course)?  Has anyone tried that?

 

Just ignore me if I'm being dumb. 🙃 

Posted : 02/04/2021 7:05 pm
jsw
 jsw
(@jsw)
Noble Member
RE: PC killed my textured sheet - calib square won't come off

I would ditto suggestions for refrigerator, freezer, maybe freeze spray.

I have one non-Prusa printer that has a glass plate and, release agent or not, large prints stick very well to it.  15 minutes or so in the refrigerator really helps.

If all else fails, maybe CAREFULLY applying a heat gun might help, but I would not try that until it's certain that it's really stuck.

Posted : 02/04/2021 9:23 pm
hawai
(@hawai)
Estimable Member
Topic starter answered:
RE: PC killed my textured sheet - calib square won't come off

Thanks everybody for chipping in with the good ideas.

 

Unfortunately the sheet is now pretty much ruined after I froze it and tried to get under the single layer with a blade. Luckily it has another side I can ruin until a replacement arrives.

I was also thinking about overprinting the square with a few more layers to get some leverage but didn't dare to try in case it got stuck as well and I couldn't use the other side any more.

At least I learned that the original plan why I got the PC wouldn't have worked out so well. It should have been part of a test series to find amaterial from which to print rather thin grass blades for a project I'm currently working on. Maybe I should have started a thread in the "how do I print this" forum earlier.

Posted : 02/04/2021 11:34 pm
jsw
 jsw
(@jsw)
Noble Member
RE: PC killed my textured sheet - calib square won't come off

When I was new to using the Prusa with the flexible sheets, I ruined one side of a smooth sheet by getting impatient and using a kitchen implement to pry off a sticky ABS print.  The side of the plate is still usable for smaller prints and I do occasionally use it.

Had I simply waited for it to cool down more, and/or obeyed TFM and used a release agent, it would have been find.  These are stumbles while climbing the learning curve.

Posted : 02/04/2021 11:51 pm
RedDawg
(@reddawg)
Estimable Member
RE: PC killed my textured sheet - calib square won't come off

If you are resigned to trashing the sheet, you might as well try the overprinting with a thicker structure to have it bond with the stuck layer (details further up in this thread). Worst case is it hastens the sheet's travel to the trash can. But if it works, please let us know; it might save some grief for someone with the same problem, with a way out of it.

1. "Creativity is the sudden cessation of stupidity." and "Any problem can be solved with the materials in the room." -Edwin Land, inventor of the Polaroid Land Camera. 2. "If I can't fix it, it isn't broken." -Me....
Posted : 03/04/2021 1:03 am
RedDawg
(@reddawg)
Estimable Member
RE: PC killed my textured sheet - calib square won't come off

If you are resigned to trashing the sheet, you might as well try the overprinting with a thicker structure to have it bond with the stuck layer (details further up in this thread). Worst case is it hastens the sheet's travel to the trash can. But if it works, please let us know; it might save some grief for someone with the same problem, with a way out of it.

1. "Creativity is the sudden cessation of stupidity." and "Any problem can be solved with the materials in the room." -Edwin Land, inventor of the Polaroid Land Camera. 2. "If I can't fix it, it isn't broken." -Me....
Posted : 03/04/2021 1:04 am
Swiss_Cheese
(@swiss_cheese)
Prominent Member
RE: PC killed my textured sheet - calib square won't come off

I will concur with 3delight suggestion, while I have had the freezer work for me, the one time it didn't, I used boiling hot water and sacrificed the print to save my sheet, BTW I use elmer's disappearing purple glue stick two strong layers and haven't had a problem with it and don't get glue texture lines from it. I put on two layers crisis cross, but allow the first layer to dry before applying the second.

 

Good Luck to you,

 

Swiss_Cheese

The Filament Whisperer...
Posted : 03/04/2021 1:09 am
hawai
(@hawai)
Estimable Member
Topic starter answered:
RE: PC killed my textured sheet - calib square won't come off

Status report update 🙂

I managed to get most of the PC off the sheet simply using the scraping side of a kitchen sponge and some patience. That part of the sheet looks rather poor but probably still usable. Just about to redo the z-height adjustment, starting with an offset of ZERO.

 

I don't think the overprinting would have helped in my case as the plastic was seriously smeared into the nooks and crannies of the powder coated sheet.

 

@Swiss_Cheese: Thanks for that suggestion, I will take that on board for further experiments with the PC-Blend stuff.

Posted : 03/04/2021 3:18 am
hawai
(@hawai)
Estimable Member
Topic starter answered:
RE: PC killed my textured sheet - calib square won't come off

@reddawg

Would have loved to take one for the team, but the other side is still in perfect working condition. Hence I was reluctant to add something to the bad side that might not come off, leaving me with a deformed and useless sheet.

I will keep that in mid though and should this or another sheet come to the end of its useful live I'm sure there will be corner left for some experimentation.

Posted : 03/04/2021 3:21 am
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