Glass bed delamination and glass replacement

Hi all,

How easy is it to transfer the Silicon heating pad to a new piece of glass? Is it just a peel-off, press on sort of thing?

I was printing ABS with a bed temp of 85, I used the ABS Juice on bare glass, which has worked quite well. When I came in the next morning, I noticed the corners of the parts had lifted, so I took them off. They all came up with little to no resistance. I was examining one to see how the layer adhesion looked and when I flipped it to look at the bottom layer, I noticed that there was almost a “puddle” of glossiness on it. I was confused and examining it further, realized that it was part of the glass bed. I looked at the bed, and sure enough there’s a divot in it. There are no sharp edges, I can run my fingers over it just fine, but it left pretty deep divots in 4 places in the glass. Has this happened to anyone else?

Did you remove the PET surface? The silicone heated bed is somewhat difficult to remove. You may not be able to do so without damaging the heater. It may be easier to place a new piece of glass over the existing bed, and use binder clips to secure the bed to the assembly. If you don’t mind, is this a stock TAZ? Mind sending in your 3D printer serial number/order information to

I did remove the PET surface, I actually had better luck printing ABS on bare glass with a little bit of the ABS juice.

Would I need to compensate for the additional layer of glass by turning up the heat or doing anything different?

It is a stock TAZ 4, purchased at the beginning of June. I’ll e-mail my info in now.

This would be a good candidate for some 3M adhesive and a sheet of PEI.


I’ve had the same problem. In the end more and more patches went. I thought i might have overdone it on the concentration of ABS in ABS/acetone goo or edged the temperature too high. I only did it because it was so hard to keep the ABS adhered to the bed for the whole duration.

I ordered a new glass sheet and have been working with this sheet on top of the old because i could not gather the enthusiasm of transferring the heating pad to the new glass bed. I remodeled and printed the bed corners to clamp the thickness of 2 glass sheets. So far so good. At least the glass hasn’t come off with the print yet. I still use goo (in lower concentrations) and i need about 100 dC for an ABS to stick reliably. Rafting helps when the corners are sharp but is a pain to remove for ABS. I wait a little longer for the temperature to stabilise because of the double layered glass. It takes a little longer to cool down too. The added inertial mass on the Y axis did worry me a bit but i’m running Y accelerations at stock default (3000 mm/sec^2 i think) and there’s not been any belt slippage (yet). Y-stage stepper motor might be working harder than it should.

I’m still weary to try models with a large contact surface with the print bed and i’m slowly working up to it.

Other users have also encountered flaking or delamination when removing parts when printing on bare glass. We recommend printing with either the stock PET surface, or with the new PEI print surface that some of our more advanced users are using with great success.


I just experienced this for the first time after 2 years of use. Funny thing is that I use purple gluesticks and the part was printed overnight and had completely cooled. the part along with the portion of glass that laminated was 100% detached although sitting exactly in place. I would never have guessed the glue would have been strong enough. I’m thinking of filling in the void with epoxy and laying a pei sheet on it. any idea of what filler to use? JB Weld? some other 2-part epoxy? Bondo?

The issue isn’t the void, it’s the different rate of thermal expansion and contraction. The surface is already damaged and compromised. Best case scenario the plug pops out. Worst case scenario, the remainder of the plate shatters. I’d just grab a new plate sandwich

I didn’t think of that. I’m trying to avoid spending too much, and was hoping for a cheaper answer.

You could always go for the aluminum bed plate mod. I’m not sure that technically counts as cheaper though.

It’s salvaging the bed heater that concerns me. I really don’t want to spend that kind of money on something that wasn’t the problem in the first place.

Does anyone know what glue lulzbot uses to attach the heater to the glass? I’m looking for some type of solvent that will help remove the heater without ruining it. Thanks, Greg.

I’m not entirely sure what it is. i know it comes pre applied to the heaters with a removable backing paper, so it isn’t contact cement, and I know that citrus based glue removers like goof off will remove it. The downside to using that approach is you get a citrus oil residue on the rubber that is difficult to remove to reapply new glue. Contact cement would likely work for re-applying the heater. Some people have had luck with freezing the assembly then peeling the heater off starting with a corner. you run the risk of broken wires that way though.

I froze mine down to below 0f and the pad came off rather easily with all the glue remaining on the glass. I checked the heater with an ohmmeter before and after removal and the resistance stayed the same so I think I’m good.

just wondering, did you put it outside to do that, I see you’re in Alaska, and I have no idea if it is that cold there yet.

Nah, I’m on the southern coast, it’s around freezing at night, not much colder. I just threw it in my chest freezer, it stays around -5f

What adhesive did you use to put it back on?