powder coated bed not sticking without glue?  

RE: powder coated bed not sticking without glue?

Wow! Thanks. Struggled with my new build MK3S and getting PLA to stick to the powder coated sheet. IPA wouldn't do it. After finding this thread, I use a little Dawn dish washing soap and a scotch brite pad.  Worked wonders!

RE: powder coated bed not sticking without glue?

Another thing to try if both IPA and dawn fail is to dry your filament.  Several of mine become less sticky and more stringy when moist. 

RE: powder coated bed not sticking without glue?

Hi guys,

I ordered my powder coated sheet a month ago, but I was only able to take a try with it today.

I was so confident about that I will just change the sheet & re-calibrate the Z-height and everything will be fine. Uhhum, that's what she said...

The first layer calibration was fine - sticked well, the texture was great, and then I thought, time to print the Prusa logo which came with the printer on the SD-card! Until 6th or 7th layer the print was great, stucked well - then suddenly detached from the sheet! I cleaned with IPA 99% 3 times, and it still detached...Second time I was almost unlucky because the nozzle just cached the part and started to burn it almost.

I was trying to print the  silver PLA which came with my printer - probably I shouldn't print with PLA?

Other thing: I found an interesting noise while the powder coated sheet was on my bed. When the bed temperature started to be 50+ degrees, a weird noise came from the direction of the EINSY/LED from the bed. When I switched back to the original smooth PEI sheet, this noise just stopped instantly. Do you have any explanation of this? 

Thanks in advance.

BR,
Adam

RE: powder coated bed not sticking without glue?

@adam-jonas-91

you can try washing the sheet with dish soap, plain dawn or palmolive, and drying with clean dry paper towels.  handle by the edges of the sheet only and then wipe with IPA and try a print again.  It is pretty common for this to happen with new plates.  It seems there is a buildup of something that happens with PLA and the PC sheets that only dish soap can remove. 

Do not use acetone on the PC sheet.

just rinse the soap off with running water in the sink and dry immediately.  dont soak it or anything and dry it off immediately after.

this does not need to be done too often, but only infrequently.

as to the noise, I do not know but it could be a rattle from the plate not being squarely on the bed and vibrating....

RE: powder coated bed not sticking without glue?

@jbinfl

I forgot to say, but I also tried to wash it with soap before the 2nd try. Just a little bit strange for me that the print doesn't stick that well on the powder coated sheet.

Anyway, as I saw yesterday evening, so many people struggling with PLA - probably I should use the smooth PEI sheet when I want to print with PLA?

I will check how planar is the powder coated sheet what I received - but what can I do if this causing this clicking sound? (By the way, it's still interesting it only comes after a given temperature, and I'm not sure if it's going to cause any damage on my printer.)

RE: powder coated bed not sticking without glue?

I wonder if posters are not talking at cross purposes. I think some are talking smooth powder coated and some textured powder coated.

RE: powder coated bed not sticking without glue?

Posted by: @towlerg

I wonder if posters are not talking at cross purposes. I think some are talking smooth powder coated and some textured powder coated.

It only recently made a difference. The care and maintenance instructions were originally identical between the two. Prusa updated the textured sheet product description and care instructions in early 2019 in response to issues with the textured sheet although they refuse to acknowledge this fact. 

RE: powder coated bed not sticking without glue?

@adam-jonas-91 - I do two things to ensure that my parts stick to my textured powder-coated sheet:

• I wash it frequently (about every 3-4 prints) with dish soap and water
• I set PrusaSlicer to use a 4mm brim for any parts with small contact area

This assumes you have properly calibrated the first layer height. The little test patch built in to the printer isn't as useful as a 60mm diameter disk. Print the first layer of the disk and if you see gaps between the lines as the area fills in, adjust live-Z a bit lower. Raise it if it tears or the print head pulls some plastic off. When you remove the disk after the bed cools, you should not be able to tear apart the filament lines easily if the Z height is properly adjusted.

Another thing you could try is to buff one side of your textured powder-coated sheet with a kitchen scrubbing pad for printing PLA, and leave the other side pristine for printing other materials. I haven't needed to do this yet but I keep thinking I should. I was also considering fine sandpaper. I'm not yet ready to make a permanent change to the surface of sheet.

The final thing I do is watch caerefully the first couple of layers as they print. If they lay down OK without lifting or tearing, then I can let the printer go on unattended. If I see any problems (globs, tears, loose lines) I abort the print, wipe the outside of the nozzle clean with a dry paper towel while it's still hot, wash the sheet if I saw anything lift off it, and try again. I have learned that accidentally touching the surface with my fingers creates a spot where the filament doesn't stick well, and alcohol isn't enough to clean it.

RE: powder coated bed not sticking without glue?

You absolutely have to have a good first layer calibration.  Too low and too high can adversely effect the adhesion.  I use the same list On both the smooth and powder coated.     

My fixes start at the top and work down:

1. Clean with IPA - spray on while cool, let it sit for 5-10 seconds, and wipe off with low lint paper towel.
2. Clean with Dawn and water.  I use a non-abrasive sponge to gently scrub.  
3. Check my first layer.  

I have never failed until my Pinda probe failed this weekend.  I am replacing it.   

RE: powder coated bed not sticking without glue?

I just finished assembling my MK3S.  I ordered it with the powder coated sheet because I eventually want to print PETG.  In the meantime I am learning to print PLA.  I had a hard time getting the first layer to stick.  I tried washing the sheet in soapy water, cleaning with Isopropyl Alcohol, and finally got 1 in 3 first layers to work by calibrating the Z offset.  That was with the Prusa PLA included.

I tried to switch to another PLA so I could print another color.  However, now I can’t get the first layer to stick even after going through the same steps.  During the calibration, the initial lines will stick after adjusting the Z offset to significantly more than the Prusa PLA, but the final rectangle at the end consistently peels off and globs onto my hot end making a mess of it.  I’m about out of patience having cleaned it and retried the calibration so many times.  I need to be able to use this printer with non-prusa filament as it costs so much to ship the Prusament from Czech to the US. 

Any suggestions would be much appreciated!

RE: powder coated bed not sticking without glue?

1) Order a smooth PEI sheet. Does not have to be Prusa.

2) Print a calibration square / circle, not the internal one. Post the result here.

Base it on:

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

I get good results with the textured sheet - but it is harder to get used to.

RE: powder coated bed not sticking without glue?

@the-baron

As I and others have stated, either buy a smooth PEI sheet, or "sacrifice" one side of your powder-coat sheet by abrading it a bit with a scouring pad to increase the micro-surface area, which should help adhesion (disclaimer: I haven't tried this, but am prepared to do so if non-Prusa PLA turns out to have issues).

RE: powder coated bed not sticking without glue?

Posted by: @anachronist

Posted by: @tim-m30

For Powder Coated sheets, an initial SOAP and HOT WATER wash has been found to be an effective way to improve PLA adhesion. 

YES!! Thank you! That did it for me. I just finished building my MK3S with a powder-coat sheet, and have spent the last several hours recalibrating, cleaning with 99% isopropyl alcohol, calibrating again, trying the first test print on the SD card... and the print kept peeling off the bed in a corner, or the middle of the first layer.

Then I saw this post, took my steel sheet to the kitchen and washed it thoroughly in warm water and a lot of dish soap, then dried it with clean paper towels without touching it with my hands.

After going through the recalibration again, the PLA is finally sticking! My first test print (the rectangular plate on the SD card) is looking beautiful.

I do not believe it, it a positive sense. After hours and hours of extremly frustrating calibration activities I finally stumbled across this post. It works, it really works!!!

RE: powder coated bed not sticking without glue?

I can basically confirm the "wash with warm water and soap" approach. Frankly, PLA combined with the textured sheet never worked really well for me, I always had to use a glue stick to make it work. For I while, all I had was the Prusa i3 Mk3S with the textured sheet. Only after a hint from a friend I ordered the PEI sheet, which opened up a completely new world of carefree PLA printing for me. So I simply used the textured sheet for PETG and the PEI for PLA.

Then after several hundred hours of printing PETG on the textured sheet, I started to run into first layer adhesion problems which I had never seen before. As much as I tried to clean the sheet with isopropanol pads before every print, small pieces simply did not stick reliably any more. Unfortunately I had not found this post then, so I had to come up with the idea myself so soap it down. Ever since my problems are solved. 

Also I see no problems with getting the sheets wet, if they are wiped completely dry immediately afterwards, but that is everyone's own responsibility of course.

Long story short: Also for printing PETG, I think it is a good idea to clean the textured sheet with warm water and soap every once in a while.

RE: powder coated bed not sticking without glue?

Unless I am badly mistaken, the official line is to NOT clean the textured powder-coated sheet with acetone, ever.

RE: powder coated bed not sticking without glue?

@jsw - acetone should never be used, and nobody is advocating acetone, but rather warm water and dish soap. Washing in warm water and dish soap every half dozen or so prints is the most effective way to maintain PLA adhesion to the powder-coated sheet.

RE: powder coated bed not sticking without glue?

@anachronist

I disagree with that statement.  I would say the proper statement is that it should rarely be used and only as a last resort if you have tried everything else.  It works for me to reset adhesion.  

RE: powder coated bed not sticking without glue?

@charles-h13 - we must agree to disagree, then. For me, every 6-10 prints, alcohol simply doesn't work anymore and I must wash the sheet. The true last resort would be abrading my sheet to increase the surface roughness. I haven't needed to do that yet, because washing it works. I did experimentally try to abrade a corner with a pot scrubbing pad (not the metal kind) and I found that the powder coating is apparently tougher than the scrubbing pad material and isn't disturbed by it. So if I do need to roughen the sheet, I'll have to use steel wool.

Destroying the sheet isn't a big deal. It isn't a permanent component of the printer. I consider it a consumable item, like filament or blue tape or ABS glue, although the sheet lasts longer.

So far I have used only one side of the sheet for printing. I had made a small scratch in the white triangle on the edge to mark the surface I use, but now that I've made a few prints with PVA, I find that the PVA itself marks the powder-coated surface, so it's easy to tell which side I've been using. It looks like the PVA is leaving an unremovable residue (I can't wash off the faint marks where PVA had been stuck). It seems that PLA sticks better to the areas where PVA had been, but I can't be 100% sure of that until I print PVA all over my sheet.

RE: powder coated bed not sticking without glue?

Posted by: @anachronist

[...] Destroying the sheet isn't a big deal. It isn't a permanent component of the printer. I consider it a consumable item, like filament or blue tape or ABS glue, although the sheet lasts longer.

That's really the crux of the matter. Although Prusa's official stance is that ONLY isopropyl alcohol should be used, there's really no warranty on these sheets. Contact Prusa support with a problem with a brand new sheet and they'll immediately let you know the sheets are consumables. At that point, what does it matter what Prusa's position is so long as you get some adhesion? In my case, I was getting poor adhesion with PLA and PETG. I tried the Dawn wash, isopropyl alcohol, acetone and mild abrading with a 3M 7445 pad. Fortunately, I had options, but if that had been my only sheet, I'd have tried hairspray, glue stick, MagiGoo, VisionMinder and any other stuff to try to get anything to stick.

None worked, so I ditched the Prusa textured sheet (sent it to @vintagepc for testing) and replaced it with a clone sheet that has worked beautifully with PLA, PETG and a host of other materials.

I suggest folks try the official procedure with isopropyl alcohol 1st and focus on a good Live-Z adjustment. If that fails, do whatever works and official instruction be damned.

RE: powder coated bed not sticking without glue?

Chemical Resistance of Specialty Thermoplastics: PEI - acetone and others