Discolored spot showing up on bottom of part

I have a discolored (white) spot showing up on the bottom of my parts printed on the TAZ5 plate. Is my bed adhesion too high? Or is it being caused by something else? I’m printing with ABS material from Lulzbot store online. Running 230 nozzle temp, 100 bed temp.

I see some discoloring on everything I print on the PEI bed but not as pronounced as you show. I always thoroughly clean the bed with acetone before printing. I also often paint my printed parts with acetone, especially the side that was on the bed, this almost always removes the discoloring.

John

I dont think acetone is good for the pei surface. Acetone is fine on pet tape. Cleaning the PEI should be alcohol wipes

Interesting, I have never seen discoloration on any of the PEI beds I’ve printed on for the last year. Is this the LulzBot PEI? Is it different than the PEI we use from Amazon and McMaster?

I bought my PEI from Amazon right after I got my TAZ4. I’ve been cleaning it aggressively with acetone for months (didn’t know otherwise) I’ve seen no noticeable degradation to the PEI? I also frequently use a very diluted ABS juice on the PEI for parts prone to lifting/warping to increase adhesion (this was suggested elsewhere on this forum). You have to be careful with this because if you use a lot of ABS in your juice you won’t be able to get the part off the bed without damaging the part or the PEI. The discoloration I see is usually very sleight but very noticeable.

An acetone wipe really should not harm the PEI (http://www.astisensor.com/ultem.pdf) but, acetone is nasty stuff so be careful. Isopropyl alcohol is safer for both you and the PEI.