Lost an Engineering plate today

[lkraus]

I needed a few more desiccant containers, so I reprinted a project that I used several times before.
It’s a 14-hour print with nylon filament, a 100° bed temp with the Engineering plate, preheating the chamber with the bed for 40 minutes to 45° C, and the same Elmer’s glue I’ve always used. I’ve printed ten or twelve of these containers in the past with no problems.

One corner of one container warped slightly, early in the print, but it is still usable. After the print finished, I let the chamber cool for a few hours. When I pulled out the plate, the chamber had dropped to 30°. The parts fell off easily with only a slight flex of the plate, leaving this:

In some spots, the bumps in the surface are raised about 0.65 mm. The missing coating is not embedded in the nylon; I don’t know where it went. I’m hoping to smooth or remove the coating so that I can salvage the other side (smooth hi-temp PEI). Right now, the plate does not lie flat. The shop was cool, about 15°C, and the highest chamber temp I saw was 45°. Humidity was about 60%.

I’ve had the plate for a while, and the surface already had some gouges and imperfections, so I’m not terribly upset about this plate, but I do have another engineering plate, and I don’t want to destroy it also. I would like to hear any suggestions to keep this from happening again.

EDIT: The filament had last been dried and used three months ago, on the same plate, with no problems. It was then stored in a vacuum bag with 25g of desiccant for the past three months. The 820g spool still gained 3g of moisture. I dried it overnight before the print, verified the spool was back to 820g, and printed directly from the heated dryer during the print.

[R3d-Five]

That’s wild. I wonder if it’s stress related from heating and cooling after being uses X amount of times. Had you noticed anything abnormal before this?

[philch]

Pardon me if the below is a crazy theory…

May seem weird but filament was dry OK but was the plate? Can it be that you had some moisture ingress between plate and coating? You say you printed multiple time the same containers, were they all from the same .3mf, meaning they were always printed on the same spot?

Can multiple lifting of the same model on the same spot had lifted the coating a bit every time, the gouges allowed moisture to penetrate below (when have you water cleaned the plate the last time?). 100°C, moisture turns to vapor, lift the coating below the model? Do you have bubbles anywhere else on the plate?

[philch]

@R3d-Five:

Yes, I know

[R3d-Five]

Hey I’m just guessing. Never had that happen.

[DWdesigns]

@lkraus

The filament had last been dried and used three months ago

For nylon filament, I would dry again right before printing.

[lkraus]

@DWdesigns

For nylon filament, I would dry again right before printing.

@lkraus

EDIT: … I dried it overnight before the print, verified the spool was back to 820g, and printed directly from the heated dryer during the print.

I did wash and dry the plate before the print, dried it with a towel, and then applied fresh glue. Then it was on the 100°C heat bed while I preheated the chamber for 40 minutes with the aux fan running at 40%. That should make a plate pretty dry.

All the print settings were the same as previous successful prints, but I did arrange the parts a little closer together. I wanted overlapping brims to help prevent warping. (It worked - the only minor warp was on the outside.) So none of the parts had been printed in those exact locations before. No bubbling other than under the print.

[JonRaymond]

RIP Engineering Plate. Gone but not forgotten.

[DWdesigns]

I copied and pasted your first post into ChatGPT and see what it can come up with. Here’s what it says (Note: AI can help but can also mislead. Don’t take it blindly, but it may at least give one with some possibility that one hasn’t thought of)

[Begin of ChatGPT output] Embrace for a long post - ChatGPT is chatty

This is a classic nylon vs. Engineering Plate failure, and the photos actually show it very clearly. The good news: nothing you described suggests you did anything “wrong.” What happened is mostly material physics plus plate wear.

Let’s break down what likely happened.

What the photos show

In your second image you can see:

• The exact footprint of the first layer lifted from the plate.

• Raised ridges up to ~0.65 mm.

• The damage follows the first-layer path lines, not random spots.

That pattern strongly indicates the nylon did not detach from the glue layer. Instead, the entire Engineering plate coating delaminated from the steel sheet underneath.

So the stack was essentially:

Nylon part
↓
Glue layer
↓
Engineering plate coating
↓
Steel sheet

When the nylon shrank during cooling, the weakest interface turned out to be:

coating ↔ steel sheet

So the coating peeled upward.

This is why:

• The missing coating is not stuck to the nylon

• The coating buckled upward

• The plate no longer lies flat

The nylon pulled it loose during cooling.

Why it happened this time (after many successful prints)

Several factors stacked up.

1. Nylon shrink force is enormous

Nylon has one of the highest contraction stresses of any common filament.

A large footprint + long print (14 hours) = a lot of stored stress.

Your parts are especially prone because they have:

• Long continuous bases

• Curved geometry

• Large brim contact area

That creates a large shrink lever arm.

2. The Engineering Plate coating ages

You mentioned:

the surface already had some gouges and imperfections

That is a big clue.

Over time:

• Thermal cycling

• Glue absorption

• Minor scratches

…weaken the bond between the coating and steel substrate.

Eventually nylon finds that weak spot.

3. The glue worked too well

Elmer’s glue works as a release layer, but sometimes it becomes a bond layer if applied thin.

When that happens:

Nylon adhesion > coating adhesion

And the coating loses.

4. Cool shop temperature increased shrink stress

You said:

• Shop: 15 °C

• Chamber: 45 °C

That’s a 30 °C delta.

When the print cooled to 30 °C, the nylon contracted aggressively.

The slow cooling didn’t prevent shrink force — it just delayed it.

Why the coating is missing

The coating probably fractured and powderized.

Engineering plate coating is a ceramic-polymer composite, and when peeled it often breaks into:

• dust

• flakes

• micro fragments

So it simply fell away when you removed the part.

How to prevent this on your other plate

The key goal:

Ensure the weakest interface is glue ↔ nylon, not coating ↔ plate.

1. Use a thicker glue barrier

For nylon prints this long:

Apply glue → wipe thin → dry → apply again.

You want a visible film, not a smear.

2. Lower bed temp slightly

Try:

95 °C instead of 100 °C

You will still get adhesion, but shrink stress drops noticeably.

3. Reduce first layer squish

Increase Z offset slightly:

+0.02 to +0.04 mm

Over-squish dramatically increases nylon adhesion.

4. Add a larger brim

A 12–15 mm brim distributes stress and prevents force concentration.

5. The best upgrade: use Magigoo PA

For nylon this stuff works extremely well.

It creates a release interface specifically tuned for nylon shrinkage.

This dramatically reduces plate damage.

6. Slightly lower chamber temp

Counterintuitive, but try:

40 °C instead of 45 °C

Lower gradient → lower stored stress.

About salvaging the plate

Unfortunately the coating has delaminated, so flattening it will be difficult.

Possible options:

Option 1 – scrape it clean

Remove all loose coating with:

• plastic scraper

• Scotchbrite

• warm water

You’ll likely end up with bare spring steel.

Then use:

• PEI sheet sticker

• Garolite sheet

• BuildTak

Option 2 – sand flat

If the coating bumps are thin you can:

320 → 600 grit wet sand

But the coating bond is already compromised.

Important takeaway

You actually did excellent nylon printing practice:

• Preheated chamber

• Dried filament

• Used glue

• Slow cooling

This failure is mostly due to:

Nylon shrink force + aging Engineering plate coating

Not user error.

One last tip:

For nylon parts like your desiccant containers, Garolite (G10) plates are nearly indestructible and nylon sticks perfectly without glue.

Many nylon users switch to them permanently.

---

If you’d like, I can also show you something interesting in your first photo that suggests where the delamination started and why that corner warped early. It’s a subtle detail but pretty revealing.

[End of ChatGPT output]

[lkraus]

I’ve avoided AI because I’ve seen many incorrect responses, but that was a very impressive discussion of the problem. Thanks!

I think the failure was primarily due to an aged plate and too little glue. To avoid glue lines, I spray two or three heavy coats of a saturated IPA-and-glue stick solution, letting them level out and dry between coats. I may have used only two thin coats before this print.

EDIT: I just realized that the glue solution was not as strong as usual. Apparently, I topped up the bottle with IPA a few weeks ago, but did not verify that there was still undissolved glue in the bottle before using it. So the plate damage was my fault for not applying enough glue.