Best Glue for PETG in 2026 — Tested Adhesives for Bonding 3D Prints
PETG is one of the friendliest filaments to print and one of the meanest to glue. The same chemistry that makes it tough, chemical-resistant, and slightly flexible also makes its surface slick enough that most household adhesives just slide off.
We spent a week bonding, pulling, and breaking PETG test coupons with every adhesive we had on the bench: cyanoacrylate, two-part epoxy, 3D Gloop, contact cement, hot glue, and PVA. Some held. Some snapped the print before the joint. Some peeled off like a sticker.
Here's what actually works on PETG, what fails, and the 30 seconds of surface prep that separates the two.
For background on the material itself, see our PETG vs PLA filament: 2026 head-to-head guide and the PETG filament temperature guide: nozzle & bed 2026.
TL;DR — Best Glue for PETG at a Glance
- Best overall: 3D Gloop PETG formula — highest bond force, chemically softens the surface, closest thing to a weld
- Best cheap/fast: 30-minute two-part epoxy — reliable, gap-filling, cheap, provided you scuff the mating surfaces first
- Best for small parts: medium-viscosity cyanoacrylate with activator — only after a 120-grit scuff
- Do not bother: hot glue, PVA/wood glue, and un-scuffed super glue
The single biggest variable was not the glue. It was whether we sanded the joint before applying it. Every adhesive here doubled or tripled in strength once the surface was scuffed.
Why PETG Is Hard to Glue
Low surface energy explained
Adhesives grip a surface two ways: they mechanically key into microtexture, and they wet out and form chemical or van der Waals bonds with the substrate. PETG is bad at the second one.
Its surface energy sits in the low-to-mid 40s of mJ/m², lower than PLA and much lower than ABS. Practically, that means glue beads up on unprepped PETG the same way water beads on a freshly waxed hood. If the adhesive cannot wet the surface, it cannot bond to it.
For a fuller comparison of the materials themselves, see PETG vs ABS in 2026: which filament to print?.
Layer lines are a feature, not a bug
The one thing an FDM print has going for it that an injection-molded part does not is texture. Layer lines are microscopic ridges, and adhesives love ridges.
Print orientation matters more than most people expect. If you can orient your part so the layer lines run across the eventual glue joint rather than parallel to it, you multiply the mechanical bite. A butt joint bonded across the grain of the layer lines pulled ~40% harder in our tests than the same joint bonded along them.
The "PETG solvent" myth
You will read in forums that dichloromethane or MEK "melts PETG." They do, technically, but not in a way that produces a useful weld on a home bench. The reaction is slow, uneven, and the fumes are genuinely nasty.
There is no clean consumer solvent that dissolves PETG the way dichloromethane dissolves ABS. 3D Gloop's PETG formula is the closest thing: it plasticizes the surface enough to fuse two parts, without being a proper solvent. That is why it works so well and why nothing else in the "solvent weld" category is worth chasing.
How We Tested
We wanted numbers, not vibes, so we set up a controlled lap-shear test.
- Coupons: 20×20×4 mm PETG blocks, printed at 240 °C nozzle / 80 °C bed, 4 walls, 40% gyroid infill
- Filament: natural-color PETG, no additives, single spool for the whole run
- Bond area: 20×20 mm flat lap joint, one coupon glued face-to-face with another
- Cure: 24 hours at ~22 °C, ~40% RH before any pull
- Pull: hand force gauge, steady load applied until failure
- Replicates: n=3 per adhesive, per prep condition (scuffed and unscuffed)
- Failure mode logged: adhesive (glue lets go from the PETG), cohesive (glue tears itself), or substrate (the PETG breaks before the joint does)
Substrate failure is the outcome you want. It means the joint is stronger than the part.
Tested Adhesives, Ranked
1. 3D Gloop (PETG formulation)
The winner, and it was not close.
- Bond force: highest of the group; in 2 of 3 pulls, the PETG substrate failed before the joint did
- Cure: handleable in ~5 min, full strength around 24 h
- Failure mode: substrate (2/3), cohesive (1/3)
3D Gloop is not a true solvent, but it does something similar: it plasticizes the top few microns of PETG so that when the two coated surfaces meet, they effectively fuse. Peel a cured joint apart on a scrap piece and you will see fibers of PETG lifted off both faces. That is the signature of a real weld.
Downsides: it smells, it gets stringy when the tube warms up, and if you leave the cap off overnight the tube is done. Buy the smallest size you will use up.
Best for: structural joints, split large prints, functional parts. If you own one PETG adhesive, own 3D Gloop.
2. Two-part epoxy (5-min and 30-min)
The reliable workhorse, with one caveat.
- Bond force (scuffed): strong; cohesive failure at ~80% of the 3D Gloop numbers
- Bond force (unscuffed): poor; adhesive failure well below the scuffed run
- 5-min vs 30-min: 30-min consistently outpulled 5-min. The longer working time lets the resin soak into the microtexture before it kicks off.
Epoxy also fills gaps, which matters when your mating surfaces are not perfectly flat (they almost never are on FDM parts). If you have a joint that will not clamp tight, 30-min epoxy is the right pick.
Best for: structural repairs, potting threaded inserts, mating uneven surfaces, gluing PETG to metal or wood.
3. Cyanoacrylate (super glue) + activator
Better than its reputation, worse than its marketing.
- Bond force (scuffed + activator): moderate; cohesive failure of the CA itself
- Bond force (unscuffed): effectively zero. The joint fell apart in the drop test 3 out of 3 times.
- Viscosity: medium beat thin. Thin CA wicks into layer lines and disappears before it can bridge a gap.
CA on PETG is fine for small aesthetic parts where the load is low and the aesthetics are high. It is brittle, so it fails badly under impact even when it holds up under steady pull. If a repaired part is going to be dropped, use epoxy instead.
4. Hot glue
Hot glue does not bond chemically to PETG at all. What it does is form a mechanical envelope around the joint that peels off cleanly the moment you flex the part.
Useful for temporary jigs, cable management, holding a fixture together while another glue cures. Useless for anything structural.
5. PVA / wood glue
Beads up, dries, peels off in one piece. Do not bother.
6. Contact cement
Middle of the pack. Held better than un-scuffed CA, worse than scuffed epoxy. Where it earns its place is large surface-to-surface bonds where clamping is awkward: you coat both sides, wait, press once, and you are done.
Surface Prep: The Single Biggest Variable
If you skip this section, the rest of the article is worthless. Every adhesive we tested at least doubled in bond force after a 30-second scuff. Some tripled.
Scuff with 120-grit sandpaper
Cross-hatch pattern on both mating surfaces. You are not trying to smooth anything. You are trying to open up the surface, add microtexture, and expose fresh polymer that has not been sitting in the air oxidizing.
Ninety seconds of light sanding on both sides is enough. Coarser than 120 chews the part; finer than 220 does not do enough.
Clean with isopropyl alcohol (90%+)
Sanded PETG picks up finger oil in seconds. Wipe both surfaces with 90%+ IPA on a lint-free cloth and let it fully flash off. If the surface still looks damp, it is still wet, and any glue you apply is going to bond to the alcohol layer rather than the part.
Pay special attention to the side that touched the build plate. Smooth PEI leaves a slightly waxy residue that murders bond strength if you glue over it.
Design for gluing
The single free multiplier nobody uses: design the joint before you slice.
- Add a 0.2–0.3 mm recessed pocket where the glue will sit. It gives the adhesive somewhere to live and stops squeeze-out.
- Orient parts so layer lines run across the joint, not along it.
- Dowel pins, tabs, or interlocking geometry outperform a flat butt joint every time. Even a 2 mm registration peg triples the shear resistance of the joint.
Which Glue for Which Job
- Splitting an oversized print into pieces: 3D Gloop, or 30-min epoxy if the mating surface is imperfect
- Repairing a snapped PETG bracket: 30-min epoxy with a full scuff and IPA wipe
- Gluing a small figurine seam: medium CA + activator, after scuffing both sides
- Attaching PETG to metal or wood: 30-min epoxy, no substitute
- Attaching PETG to PLA: 3D Gloop's PLA formula, or 30-min epoxy
- Temporary or reversible: hot glue
Common Mistakes That Kill Your Bond
Most "the glue does not work on PETG" complaints trace back to one of these:
- Skipping the surface scuff. This is by far the biggest single cause of failure.
- Using thin CA on a large mating area. It wicks away and cures before the surfaces meet.
- Clamping so hard you squeeze all the epoxy out of the joint. A glue line needs to be thin, not absent.
- Not letting the IPA fully evaporate before applying glue.
- Gluing the smooth build-plate side without sanding. PEI residue is a bond killer.
- Loading the joint before full cure. Read the label; 5-min epoxy is not at full strength for 24 hours.
Safety Notes
None of this is dangerous with basic care, but a couple of hazards are worth flagging.
- CA plus activator generates real heat in the reaction, enough to cause a small burn if you catch a drop on skin.
- Never combine CA with cotton (cotton wool, cotton gloves, tissue). The exotherm is fast enough to smoke.
- Epoxy sensitization is cumulative. You may get away with bare hands for years and then develop a nasty reaction overnight. Nitrile gloves every time.
- 3D Gloop and any solvent-adjacent adhesive want ventilation. Open a window.
FAQ
Does super glue work on PETG? Only if you scuff both surfaces with 120-grit first and use an activator. On smooth as-printed PETG, cyanoacrylate fails almost immediately under any load.
What is the strongest glue for PETG? 3D Gloop's PETG formula was the strongest in our lap-shear tests, followed by 30-minute two-part epoxy on scuffed surfaces. Both produced substrate failure: the print broke before the joint.
Can you weld PETG with a solvent? Not with anything you should keep on a home bench. No common consumer solvent truly dissolves PETG. 3D Gloop plasticizes the surface enough to act like a weld, which is the closest option for hobbyists.
Will epoxy stick to PETG? Yes, but only well if the mating surface is scuffed. Un-scuffed PETG has too low a surface energy for epoxy to grip reliably.
Can I glue PETG to PLA? Yes. 3D Gloop's PLA formula or 30-minute epoxy both work. Scuff both surfaces first and wipe down with IPA.
Does hot glue work on PETG? Only mechanically. It peels off cleanly and is not suitable for anything structural.
Verdict
Keep a tube of 3D Gloop and a syringe of 30-minute epoxy on the bench and you are covered for 95% of PETG bonds you will ever need to make. Everything else is a niche pick.
Two things matter more than which product you buy:
- Prep the surface. A 30-second scuff and an IPA wipe double every glue in this test. There is no adhesive on earth strong enough to overcome a slick, oily, un-sanded PETG face.
- Design the joint before you slice. A recessed pocket, a dowel pin, or a lap step turns a mediocre bond into a strong one. That geometry is free: it costs you nothing at print time and buys you a 3× multiplier on strength.
Print well, prep well, and the joint disappears into the part.