Prusa i3 MK3 - PEI issues after 39 days printing  

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I also have the impression that the PEI sheet changes over time and doesn't stick as well as in the beginning.

But I always get it to stick without glue stick for PLA and PETG, just need to be more precise with the Z-level and slow down the first layer more, to make it lay down well.
In my experience, the dishwashing soap + hot water + minimally abrasive kitchen sponge works very well. Maybe check if your kitchen soap has any hand care features, that might mean it contains some oils.
I haven't used acetone for a while since the soap works so well.

And I certainly have no interest in using glue stick all the time, it's a bit messy.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

If you use isopropanol, it should be 99%.
Isopropanol 70% may contain 30% of something that worsens the bond to the bed.
And as you mention, detergent and water is outstandingly good to clean the bed with.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I have loved my new MK3, but am having adhesion issues with the PEI sheet. I am using 91% isopropyl alcohol before almost every print, have washed the PEI sheet with soap and water several times, and just finished washing the sheet with acetone twice. I find that i just can't get all parts to stick to the bed unless I use glue stick. https://appsync.biz/speed-test/ https://appsync.biz/scrabble-word-finder/ https://appsync.biz/solitaire/ I haven't used a kitchen scrubber, 2000 grit sandpaper, or steel wool yet, but I have read that these are also possible solutions to rough up the PEI sheet.

Any other ideas? Should I just keep using the PEI sheet with glue stick?

At first there were no issues, and I was using 70% isopropyl from the drug store. Would denatured alcohol (mixture of ethanol and methanol) be better?

My issues has been solved thank you
________________________________________________________________________________________________________________________

Re: Prusa i3 MK3 - PEI issues after 39 days printing

Are you able to elaborate what fixed it.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I have been printing pretty consistently for about the same amount of time. I found with PLA keeping the bed to 70c and using brims were appropriate stopped all of my issues with adhesion. I have used 2 different PLAs so far, the Prusa you get with the printer and some Hatchbox stuff I got off Amazon. Zero issues since changing the Bed temp.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I got a new flat sheet, the theory being I'd keep one for glue (TPU or PETg) and one clean.

The new one, maybe there are other reasons, but it's giving me fits. I'm constantly struggling. I've washed with soap, acetone, iso, and level level level level.

Sometimes it works, and sometimes I have to start 30+ prints to get it working.

Perhaps they do "break in". Perhaps I should use the old one for "clean" and the new one for glue.

I've noticed dark spots like oil spots sometimes by parts that don't stick - and it was clean going in. I DID find going a little hotter nozzle temp made some stuff stick which wasn't before.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

my experience.

Acetone and PEI are a bad combo, it makes the PEI brittle combined with the heating and cooling cycles requiring a new sheet every few weeks if you print ABS.

PLA:
91% or higher alcohol higher the better. combine this with using a scotch bright sponge. (yellow sponge+green pad)
spray the alcohol on the bed. Scuff the bed with the green pad gently . Mop up with a lint free micromesh cloth.

PEI:
spray bed with windex glass cleaner, mop up with micromesh cloth, do not use green pad.

nylons and TPU glue stick with water and sponge/green pad clean up.

the trick is the scour pad it scratches up the surface of the PEI so that the first layer has more to bite into.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I had the exact problem.

After I actually cleaned the bed, printing has been wonderful. As a matter of fact, PLA is hard enough to knock loose it bothers me. PET is like superglue was used (and that's using Windex and intentionally fouling the bed surface with a palm print).

The risk with using detergents, especially ones with antibacterial agents that are common these days, is they leave behind ingredients that keep stuff from sticking. You have to rinse thoroughly, and if you have soft water, rinsing needs to be done a few times, drying with a fresh paper towel in between rinses. It was such a problem I no longer wash with Dawn dish soap. I'll wipe the bed with a glue stick, and rinse the glue off and dry a couple of times. Then a serious scrub with fresh 91% alcohol. I've also used acetone with good effect, usually just a light wipe is enough.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I had the exact problem.
.........

The risk with using detergents, especially ones with antibacterial agents that are common these days, is they leave behind ingredients that keep stuff from sticking. You have to rinse thoroughly, and if you have soft water, rinsing needs to be done a few times, drying with a fresh paper towel in between rinses. It was such a problem I no longer wash with Dawn dish soap. I'll wipe the bed with a glue stick, and rinse the glue off and dry a couple of times. Then a serious scrub with fresh 91% alcohol. I've also used acetone with good effect, usually just a light wipe is enough.

Regular old Dawn has worked wonderfully for me. My sheet is coming up on a year of service and is still in excellent condition and has only ever been printed on one side. At one point the wife switched from dawn to Palmolive and nothing stuck to the sheet after using it, I used Dr Bronners Pure Castile while we had the Palmolive and PLA stuck to the sheet like glue after a fresh wash with it. I guess different strokes for different folks.

Someone posted this a while ago, might help with choosing cleaning agents...

http://sevierlab.vet.cornell.edu/resources/Chemical-Resistance-Chart-Detail.pdf

Re: Prusa i3 MK3 - PEI issues after 39 days printing

my experience.
Acetone and PEI are a bad combo, it makes the PEI brittle combined with the heating and cooling cycles requiring a new sheet every few weeks if you print ABS.

IMHO as long as you don't "go crazy" with the acetone the PEI isn't adversely affected. I generally wipe down once per month with fairly constant use and not noticed any ill effects. Perhaps once per week or greater will cause problems.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I've used acetone almost weekly - and even more frequently (a couple times a day) when printing "difficult" parts. Bed is fine except where PET adhered a bit too well and I now have pry marks. Not sure what the nominal life of the bed is supposed to be, but mine is still working well many months later.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I used Acetone once in the 11 months I've had my printer and feel it cleans no better than Dawn. I've only ever printed on one side of my PEI sheet and the surface on the print side is almost as nice as the side that's never been printed on. The big exception is the purge line.

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I used Acetone once in the 11 months I've had my printer and feel it cleans no better than Dawn.

Every time I have asked her she says it isn't her job. 😯

Guess I'll get reported now for non-PC. 😈

Re: Prusa i3 MK3 - PEI issues after 39 days printing

I put a strip of Kapton tape across where the purge line goes to reduce the effect of successive purge lines.

Joan