PETG is a pretty great material to print 3D models with, but one issue with it is that gluing it can be a bit of a pain. In a recent video by [Cosel] (German language, with English auto-dub) he notes that he found that with many adhesives the adhesion between PETG parts would tend to fail over time, so he set out to do a large test with just about any adhesive he could get his hands on. This included everything from epoxy to wood glue and various adhesives for plastics
For the test, two flat surfaces were printed in PETG for each test, glued together and allowed to fully dry over multiple days. After about a week each sample was put into a rig that tried to pull the two surfaces apart while measuring the force required to do so.
With e.g. two-part epoxy and super glue the parts would break rather than the glue layer, while with others the glue layer would give way first. All of these results are noted in the above graphic that has the force listed in Newton. The special notes and symbols stand for strong smell (‘Geruch’), the PETG itself breaking (‘Substrat gebrochen’) and high variability (‘hohe Streuung’) between the multiple samples tested per adhesive.
Interesting is that multiple superglues (‘Sekundenkleber’) show different results, while MMA (Methyl Methacrylate) and similar score the highest. The Bostik P580 is a polyurethane construction adhesive, usually used for gluing just about anything to anything in interior and exterior applications, so perhaps its high score isn’t so surprising. Trailing at the end are the wood glue in last place, with the UHU general adhesive also scoring rather poorly.
Clearly there are many options for gluing PETG parts, but some are definitely more sturdy than others.
Thanks to [Risu no Kairu] for the tip.
I do a lot of 3D printing using PETG, so this is very helpful. Many thanks for quality citizen science!
I’ve heard some people use flame or plasma to activate surface energy of PETG to bond more readily with glue and paint. Haven’t tried yet.
I have used a product called TAP Polyweld, which is for gluing HDPE together. The secret is in the surface prep, you need to flame both surfaces. It actually works great, I need some right now and I think I have enough left, but I was looking for it online and it has been discontinued, with no explanation. I can’t find any adhesive anywhere that mentions polyethylene on the label, nor anything that mentions the flame treatment.
Does anyone know what happened? It just says discontinued and there’s no warning to discard any you may have. Or is there hopefully some new formula that makes it easy?
I dont like to use glue at all. I prefer to bond parts with plastic welding instead. Depending on the part I either use a modified soldering iron, an ultrasonic cutter, or a 3d printing pen. I get that glue is easier, but if you dont mind surface finishing work, welding really gives a superior result. YMMV
this is probably the better idea, pvc pipe welding solvent is the one I think?
Thats chemical welding. While that works, if you choose the right solvent for the plastic youre working with, I dont love handling solvents.
Thermal bonding just makes the most sense to me when dealing with fdm parts.
Haha, before even opening the article I thought to myself “I bet UHU is at the bottom of the list”
What a suprise….
I genuinely don’t understand how they are still in business
Stores stock it because people buy it, and people buy it because stores stock it.
PVA glue is missing from that list.