PLA not sticking???  

RE: PLA not sticking???

Soap and water is amazing.  It works.  

RE: PLA not sticking???

So much frustration for weeks, trying to solve those first layer issues... and soap + water solved it...
So IPA 99% I was using trying to get the bed clean do NOT work as I thought...

I followed the instructions Randy's advise (page3 but others pointed in the same direction), and it was like magic.

I pasted below part of Randy's post below is someone would need.
Hope it will help.

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The Prusa manual says to use alcohol to clean the print sheet. They even include an alcohol wipe with the printer. But cleaning the print sheet with alcohol only works to a point, and only temporarily. The alcohol will break down some of the plastic residue and dilute it, allowing you to move it around. But repeatedly wiping down the build sheet with an alcohol soaked paper towel only redistributes the residue, it doesn’t remove it. Eventually, there are so many slippery molecules of plastic left behind on the bed after the alcohol evaporates, new prints will refuse to stick any longer.

At this point, an acetone treatment, because it’s a very aggressive organic solvent, may give you back some lost bed adhesion by breaking up some of the residues and allowing them to be mostly wiped away. This process potentially also etches the surface layer of the PEI sheet, exposing fresh material to adhere to beneath.

I’ve learned what works to really clean the print sheet without causing any harm to it from many of the good users in these forums, so I want to pass it forward. Frankly, I’m surprised none of the mods has taken one of the excellent posts on effective cleaning tips and made it a sticky at the top of the ‘Assembly and first prints troubleshooting’ sections. It’s an issue so common and so baffling, it deserves a permanent place there.

A serious deep cleaning of your build sheet requires a trip to the kitchen sink, or shop/laundry/slop sink if you have one. You will need three common household items and lots of very hot water.

First you will need Dawn Dish Detergent (in the U.S., Farie in the U.K.) with no additives or fragrances. We’ve all seen the Dawn commercials where they use the product to clean birds and wildlife that have been caught in an oil spill. This is actually a proven use case which works because Dawn contains surfactants which allows the water molecules to attach to the oil molecules and flush the oil away from the animal. The same principle works with our print sheets. The surfactants in the detergent allow the leftover polymer molecules on the build plate to attach to the water molecules and float them away. I have experimented with other dish detergents and found I actually had worse adhesion after cleaning than before.

      (note: I used basic dish detergent, a 'nature friendly' one and it worked well on my side)

Next, you need a brand new, unused non-scratch abrasive scrubbing sponge. Something like the yellow sponge with the rough green scouring surface on one side, marketed under the Scotch-Brite brand. Do not, under any circumstances, use a sponge that has been used to wash dishes or has come in contact with food. This will completely negate your efforts and your build plate will end up slipperier than when you started. And don’t use an abrasive sponge containing metals or other aggressive scouring materials.

Finally, you’ll need some clean dry paper towels.

Wet the print sheet thoroughly with the hottest water you can stand. Generously apply Dawn Dish Detergent to the surface and scrub vigorously with the scouring sponge until the detergent builds a thick, heavy foam. You may need to rinse and repeat more than once. Use lots of hot water. You need to break up and float off the residue. 

Avoid touching the surface of the plate with your fingers. Hold it by the edges only and/or wear a pair of clean,non-powdered disposable gloves. When you’ve finished with one side flip it over and repeat on the other side. Rinse any soap and residue completely.

When finished cleaning, remove the plate from the sink, handling only by the edges, and immediately and thoroughly dry with clean paper towels.

Return the print sheet to the printer, align & Install on the heatbed (all without touching the surface with your fingers), and run a preheat routine for any filament in order to insure any remaining moisture is driven out of the print sheet. Once you reach target bed temperature you can either start a print or cancel the pre-heat routine.

Do not wipe the sheet down with alcohol and do not wipe the sheet down with a microfiber cloth or any other material. Make your first print on the freshly washed and dried surface and see what your results look like. That should be all you need.

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RE: PLA not sticking???

Try CGMaxed PVB based printer bed adhesive. It's less expensive than the PVA based adhesives and you get a lot of it. 6oz for 22 dollars on ebay. I use it on all my prints. It's incredible.