Gluing Plastics / Filaments / Parts

[scampa123]

I'm curious if folks have recommendations on which glues are the best for gluing parts together. ..I figured a thread on this would help others too

I'm sure it depends on the filament, so let's name a few out (others welcome!):

• PLA
  PETG
  ePC
  NinjaFlex

Anyone have suggestions?

[Tim]

Methylene Chloride is the best for PETg and PLA. The easiest form to get it in is a can of Weld-On #4. The label on the can mentions polycarbonate, so chances are that it works well with ePC, too, although I haven't tried. It comes in a very thin liquid that is best applied by clamping the parts together first and then dripping the solvent into the seam.

2-part epoxy works reasonably well with PETg and PLA. Cyanoacrylate (super glue) is okay but has no shear strength.

[jimc]

yes, I second tims advise. methylene chloride is what you want. it works for almost all plastics except nylon. always use it in a well ventilated area. its a pretty toxic solvent. but it with a needle applicator bottle. you want a fine gauge needle. around 28ga. ninjaflex is a no go. your really not going to glue that stuff reliably with anything and have a super strong flexible joint.

[Tim]

buy it with a needle applicator bottle. you want a fine gauge needle. around 28ga.

I got mine off of Amazon, e.g.,

http://www.amazon.com/SCIGRIP-10308-Acr ... FWTX1D1V1K

for the solvent and

http://www.amazon.com/Applicator-Bottle ... KJDZFJPQRS

for the applicator bottle with the needle. It's a 25 gauge needle, works okay for me, but occasionally gets clogged. When that happens, I've usually been able to get it unclogged by dipping the tip back into the solvent and wiping it clean.

I recommend getting a small metal funnel for pouring from the can into the applicator bottle, because the can is definitely not made for convenient pouring. Don't put more into the applicator bottle than you need at a time, or pour whatever is left back into the can, because otherwise it will just sublimate right out of the closed bottle and be gone in a few days.

[willnewton]

Of course you can skip the glue and use a soldering iron at low temps for some joins. You can also friction weld by chucking a short length of filament into a Dremel. Some folks use the 3D pens as patch tools.

[jsc]

I use actual syringes for Weld-On. Easy to dispense into (just suck it up) and purge back the extra.

I went into a glue frenzy a while back and tried everything. All of the above recommendations are good, here's some additional comments:

Weld-On #4: great strength for PLA and PETG, but tends to wick along seam lines and can bleach out some filament colors, causing ugliness. Needs practice to apply well. You can use pure acetone similarly with ABS, but it is often easier to create a slurry by dissolving waste filament in acetone to thicken it up.

Superglue (I prefer Bob Smith Industries Insta-cure+), with optional accelerant: good, but weak shear strength as Tim mentioned. Still, very useful for very quick setting.

Two-part epoxy (I prefer Loctite heavy duty 5 minute in the separate bottles, not the dual-syringe applicators): also very good for strength and quickish set time. Seems sturdier than superglue in most situations.

E6000: a flexible craft glue, you might want to try it for flexible filaments, since you can use it for cloth. Very strong, impact resistant. Downsides: 24 hours to set up, smells terrible.

Gorilla Glue, the brownish stuff: terrible. Weak, foams up, I don't know why people like this thing.

Haven't tried soldering iron welding because my soldering iron is too nice to gunk up. I have tried Dremel friction welding. It works, but the result is not what you would call pretty.

[ednisley]

Gorilla Glue ... why people like this thing.

It's good for sloppy fits, where it can expand to fill the space available. Works fine in wood, good for leather, OK for bulky plastic things, moderately for fabric-to-plastic, and poorly for just about everything else.

My supply of foaming goo is solidifying in its smallish bottle and I probably won't replace it.

I use actual syringes

Protip: There exist jurisdictions in this great land of ours (*) where having a syringe, even without a needle, counts as "possession of drug paraphernalia". That you got them in bulk from eBay and use them for refilling 3D printer cartridges, oiling machine components, and gluing plastic doodads may or may not count in your favor, depending on the situation where the question comes up.

(*) The USA, in case you were wondering.

[Jules]

Protip: There exist jurisdictions in this great land of ours (*) where having a syringe, even without a needle, counts as "possession of drug paraphernalia". That you got them in bulk from eBay and use them for refilling 3D printer cartridges, oiling machine components, and gluing plastic doodads may or may not count in your favor, depending on the situation where the question comes up.

(*) The USA, in case you were wondering.

Don't even get me started.

[willnewton]

Gorilla glue was a bit of a dream come true for professional woodworkers. It moisture curing glue and wood retains ambient moisture, so was a good fit for the industry.

It has a very high initial tack so you can nearly rub two well-fitted pieces together and sit them down to cure. It also dries hard and friable, making for exceeding easy cleanup versus "yellow wood glue" which dries rubbery/plastic and is harder to sand off.

The foaming action is assurance that you are getting a good cure. It IS NOT a magical gap filling wonder glue, The foam dries brittle and provides little structural integrity, as some of you have found out. It actually requires tighter tolerance than regular glues and is not suited for all kinds of joinery.

A perfect example would be to use it for long, straight joins, such as gluing up a tabletop.

A poor example would be using it to glue Granny's falling to a hundred pieces loosey-goosey rocking chair.

To jump back on topic, it is a poor choice for 3dprints.

[jsc]

I can see how it would be handy for woodworking, and that's the context I've read most about it. But if you read the bottle it makes it sound like some sort of wonder glue that can attach anything to anything. Simply not the case for most things.