Ouch! Nasty ugly destroyed MK3S build plate. (Has anyone tried re-skinning these?)
I just got back in town, and tonight I decided to resume a few 3d print projects. The printers have been idle for about a week.
First was a couple of small pieces in the PLA silver-gray, Prusa Filament-PM equivalent, printed without a hitch. Standard protocol, wipe off the plate with alcohol, launch the print, flex the plate to remove the printed pieces, NBD. Results as expected.
Next was the bottom for a small project box. Unload the PLA, preheat to ABS temp, load Hatchbox black ABS.
Again, standard protocol for ABS prints. Wipe off with alcohol, apply Layerneer for a release agent, preheat and let the machine stabilize to ABS temperature for maybe 20 minutes or so, then launch the print.
Print went as expected and finished.
My standard protocol at the end of an ABS print is to let the plate and the print cool to almost room temperature, then flex to remove. That's what I did.
When I flexed the almost-room-temperature plate, I heard the familiar 'crack' of the print releasing, so I removed it.
However, along with the print came a HUGE section of the PEI coating (see below) which separated from the plate and was attached to the print.
The piece of PEI that came off with the print peeled off of the print quite easily in one piece.
For some reason (?????) the adhesion to the print was obviously stronger than the adhesion to the steel build plate.
The adhesive on the plate side is still tacky, but obviously not sticky enough to hold the PEI coating anymore.
I'm kind of at a loss to explain this. ABS prints using Layerneer always release easily and cleanly. I always cool them to almost room temperature and then flex the plate and they pop off.
This is (make that WAS) the 'good' side of my original plate, and the one that I ruined one side of early in the process, about two years ago, when I did an ABS print without a release agent and got impatient and pried the print off, along with a couple (much smaller) pieces of PEI coating. I've been using the 'good' side of this plate regularly for PLA, PETg, and ABS prints, and the 'bad' side for smaller prints, also with good results.
Almost coincidentally, just before I left, I ordered a 'factory second' plate from Prusa, mainly because I had read here that they may be in short supply, and I figured WTF, might as well try the factory second, which I sure cannot tell, visually, from a 'factory first' plate. 😉
So now, as far as the smooth plates go, I now have four good sides, two sides on one lightly-used plate and two on a yet-to-be-used 'factory second' plate.
I'm thinking of trying to re-skin this one, now that both sides are boogered up.
Has anyone here actually done this? If so, what did you use to remove the (remains of) the old PEI and can you comment on the technique of applying the new PEI sheets? Amazon has the PEI sheets in stock and I just ordered two, which should be here this coming week, so I want to please get some feedback from anyone who has done the PEI sheet replacement before.
Thanks in advance.
Ugly old sheet with replacement PEI as an alternative
I had one side get torn up and (eventually) did the replacement. You do want to get the old PEI off, which can be an adventure. I used plenty of limonene and scraping, but have read that something like Goo Gone is much more effective at dealing with the old adhesive. Figure an hour or so of focused work.
The replacement PEI went on easily enough. If you're doing both sides, consider using BuildTak's PEI which uses an adhesive that is much easier to work with. It will require a separate Live-Z setting though.
The biggest disappointment was how badly the sheet oxidized underneath the PEI. It looks like crap, although the sheet is perfectly fine to print on and works well.
In practical terms and for the amount of work, buying a replacement double-side spring sheet makes more sense. Back when the spring steel coated sheets were $20 or so, this was a no-brainer. The only problem with simply buying a replacement sheet is that you'll have a perfectly good spring steel sheet sitting in the corner calling to you to do something with it and your practical side won't let it go.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Ouch! Nasty ugly destroyed MK3S build plate. (Has anyone tried re-skinning these?)
I don't think the base steel plate on mine is bad at all, as in no corrosion or oxidation.
Getting the old PEI sheets off will be the Real Work (tm).
I tried testing the adhesive with a Q-Tip and acetone and it did not really dissolve it.
Googling the ingredients in Goo Gone I come up with kerosene, trace amounts of ether, and citrus oils, probably similar to limonene, so I may try to get some GG or maybe just a generic 'mineral spirit' solvent. It sure looks like the real active ingredient in it is kerosene.
The piece of PEI that came off with the print came off the print easily and was somewhat brittle, so I'm sure that the old PEI sheets will probably come off in pieces.
It will be a few days until the new sheets come in, so if needed I can soak the plate to soften the old adhesive.
RE: Ouch! Nasty ugly destroyed MK3S build plate. (Has anyone tried re-skinning these?)
[...] The piece of PEI that came off with the print came off the print easily and was somewhat brittle, so I'm sure that the old PEI sheets will probably come off in pieces.
The PEI came off fairly easily. It was the glue residue left behind that required all the work.
FWIW - The oxidation underneath the PEI happened quickly after installing the replacement sheet. Prior to that, the appearance of the damaged sheet was normal except for the missing chunk of PEI. I cleaned the steel sheet before applying the PEI, but may have missed a few spots.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Ouch! Nasty ugly destroyed MK3S build plate. (Has anyone tried re-skinning these?)
Bob, what did you use for the final cleaning of the bare steel plate before applying the new PEI?