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Quick question regarding damage control.

I put PEI on my glass this last weekend attempting to use the Windex Float method.

I made a complete mess of the whole situation. The 3M adhesive pulled up and was loose. It ended up wrinkling, trapping Windex, and generally mucking up the whole thing.

What can I use to safely remove the adhesive from the PEI? I figure I can use Goof Off to get it off the glass plate. I'm sure there will be residue on both.

Thanks

DK

You can get it off with soap and water and a lot of elbow grease, it's a pain in the ass to get it off anything.

Acetone works a treat. Pour some on a paper towel, lay that on the adhesive let it sit for a few mins. Wipe off, that's it

It's not a complete disaster, I've removed the 3M tape before. As DerStig mentions, use acetone. You will need some elbow grease and a scraper as well.

Once both surfaces are clean, apply another sheet of 3M adhesive and have another go.

GooBeGone works great to remove the tape from PEI or glass. I've removed quite a few PEIs from glass and the adhesive from both using it.

Actually I think any citrus cleaner also works.

Yes, the 3M adhesive is a real pain, because it is very unstable and has no structure on it's own. I advise you to put it on the glas first, and after drying an extended time (at least overnight!) apply the PEI to the glued glass. The glass gives the glue-film the needed stability to succesfull adhere the PEI. Anyone considering going for PEI, I would suggest the get the pre-glued kind. Once the 3M wrinkels don't bother and start over.

To encourage anyone: it's worth it!

Thanks guys. Repaired and the second try went much better. I'm pretty happy with it.

Now I just need to figure out why my deviation on my leveling system went up in the process...

I have another disaster to mention
I am using PEI on glass for a while now, and it works good, but not as well as I hoped. I have been upping bed temp to 90 to avoid ABS prints to curl up. Small parts no problem, but things like enclosure brackets are still curling up at 90C. To prevent that I have been roughening up the PEI surface with sandpaper grid 1000 a bit. Repeated that a few times because it did not seem to help much. Now it's a lot better, but the print is not popping off after the bed cooled down. Usually I give the print a firm spanking to the side to force-impact it off the bed, but that is getting more difficult now. I am too impatient to let the bed cool down completely when I have more prints to follow.

Now I used the spatula a bit to forcefully and the PEI seems to have lifted a bit, so now my bed is uneven and I can start all-over...
My ABS prints are coming off the PEI with a white discoloration on the bottom. That completely ruins the nice finish the PEI gives it.
I am thinking about heat resistant spray glue and an extra alu disc for the next sheet of PEI. Anyone tried that? I hate the 3M adhesive...

I never got great results with PEI/ABS at 90C bed temp, but it's fantastic at 110C. That was a big driver for the 24V upgrade. Prints stick beautifully and pop off pretty easily after it drops to ~80C or lower, then heat it back up for the next one. The main issue is that makes an even bigger temperature differential near the bed with the associated print artifacts.

If the print can be gripped with pliers and pulled directly upward and away from the PEI, that seems to work best, and I have no idea why. Maybe it's that I'm grabbing a corner and pulling that edge up first, then the rest releases?

Also, if it's below -20F out, you can just wave the bed around outside for a minute and release a print, while feeling vaguely like an idiot.

gchristopher wrote:I never got great results with PEI/ABS at 90C bed temp, but it's fantastic at 110C. That was a big driver for the 24V upgrade. Prints stick beautifully and pop off pretty easily after it drops to ~80C or lower, then heat it back up for the next one. The main issue is that makes an even bigger temperature differential near the bed with the associated print artifacts.

I do run the bed @20V so I can try that. But I thought most people get away with printing at just 70 or 80 C. I was afraid that if I run any higher, the part does come off even more difficultly. What exactly do you mean with the artifacts?

gchristopher wrote:If the print can be gripped with pliers and pulled directly upward and away from the PEI, that seems to work best, and I have no idea why. Maybe it's that I'm grabbing a corner and pulling that edge up first, then the rest releases?

In my opinion the 3M glue liner that is being offered by GizmoDorks is just not stable enough for this. It allows to be disformed under pressure. I am afraid to pull bulges into the PEI sheet. Although the bulge I pulled yesterday seems to be fairly straight again... I am searching for a suitable industrial spray glue to adhere the PEI directly to an alu disc, so for now I will have to do with it.

gchristopher wrote:Also, if it's below -20F out, you can just wave the bed around outside for a minute and release a print, while feeling vaguely like an idiot.

I have no problem with that, but I have not thermometer that shows F

Are you running enclosed? I am running 75c on PEI enclosed. If you need to, just grab a huge garbage bag and enclose it. You will resolve adhesion/splitting issues in the middle of the print as well.

No, I am not running enclosed yet. It's Timskloss his enclosure brackets I am printing

Another bracket finished. I removed this one with the spatula, off a completely cooled down plate. I did not pull at all, just moved the spatula from side to side. There is a white discoloration visible (on ALL my prints!). Only way to get rid of that is to sand, or flame it with a torch. But that makes the bottom of the print bulge. This happened as well before as after sanding the surface.

gchristopher wrote:
If the print can be gripped with pliers and pulled directly upward and away from the PEI, that seems to work best, and I have no idea why. Maybe it's that I'm grabbing a corner and pulling that edge up first, then the rest releases?

Pulling up on print is wrong way. You should never have to use pliers. Does it not mar the print? Often just a sharp crack with a small hammer in the right spot will release it from PEI. Sometimes putting a metal putty knife under one corner or unimportant edge and giving it a sharp CONTROLLED tap will do the trick.

One tip I learned from mhackney was to sharpen and bevel the spatula tip so it essentially it is razor thin. all you need is the proper angle to get a tiny portion underneath the print but not dig into the pei surface, then you can level the spatula and slide it underneath the rest of the print easily. I have NO issues getting prints off PEI anymore

I've lowered my bed temp to 80c and I'm not having any issues getting the piece off. I did have some problems with it curling at first but I just lowered my z=0 .05mm at a time till curling stopped


The only think I don't like about the pei is that I think it makes my IR sensor less accurate. I am thinking about building a corexy soon, and I think I might go for piezo disk leveling on that, though maybe it has the same issues with pei as the accelerometer boards do.

Qdeathstar wrote: I am thinking about building a corexy soon, and I think I might go for piezo disk leveling on that, though maybe it has the same issues with pei as the accelerometer boards do.

When I built my CoreXY I just made sure it was perfectly square and solid so Auto levelling is not needed. A properly built machine does not need auto levelling. I do have a z probe set up to just read the Z height because it is easier than doing it manually.

DeltaCon wrote:I have another disaster to mention. Now I used the spatula a bit to forcefully and the PEI seems to have lifted a bit, so now my bed is uneven and I can start all-over...

I had this same problem and found a solution. I back-drilled a very small (1/32") hole through my aluminum plate to the adhesive layer. I set the depth on my drill press so I wouldn't go through the PEI. This hole allows the air to escape and the PEI to settle back down on the plate.

After drilling the hole(s) I heated the bed back up to 100C and rubbed the high spots out of the PEI with the end of a wooden dowel working from the outside of the bubble towards the hole. There remains a slight unevenness but it seems to be less than 0.05 mm and doesn't affect my first layer.

Saves me from starting over again.

I will have to drill through my boroglass then

DeltaCon wrote:boroglass

lol, i've forgot to remove protective film from gizmodorks's sheet and applied it with 3M. Good thing i have another 3M sheet, so all i need is to disapply pei from glass

I wrote before about pulling a bulge in my PEI surface. The stupid thing is that the bulge is moving around! That indicates that there is still (after about 3 months of use!) moist in the 3M glue liner. I think it is REALLY not the best glue for the job... Anyone any luck searching for heat resistant spray glue?

I've always used 468MP and it hasn't done that.

Did you apply it wet or dry?