There is cheap super-glue and expensive super-glue. Even super cheap super-glue. They all seem to work the same. Are they different? Is more expensive a better glue?
There are a lot of different glues out there, so I can’t positively answer the question, but in my experience most things calling themselves “super glue” or some variation thereof are cyanoacrylates:
So there are different types of cyanoacrylate cements. Certainly some of them use additives to make them thicker or for other purposes, and the purity might vary as well. That might explain the differences you observe between brands.
Gorilla Glue, by the way, isn’t a cyanoacrylate. It’s polyurethane-based. But I’ve never heard it called super glue by anyone.
The original Gorilla Glue product is prolyurethane, but now they have a whole range, including PVA and superglue
Get what you pay for, if you’re lucky. “Superglues” have a shelf life, fresh stuff seems to work better. Helps if stored in the fridge. Course if we kept everything in the fridge that should be, there wouldn’t be any room for food. Good rationale for a beer fridge. Thank me later.
Looking at the range of cyanoacrylate products manufactured by Loctite will make your head spin.
There are variants for just about every application you can think of, and then about three times as many for applications you would never have thought of.
Even without getting into the question of quality of product, one thing is clear, there are better and worse adhesives for different applications.
Maybe I’m just paying too much, but I will only use a name brand superglue on something that matters. Usually Loctite. There are however times where you really don’t care and cheap is good. When you only need it for a temporary fix, then the no-name stuff is quite adequate.
Even aside from the quality of the product, there’s also a lot of variation in quality of the packaging. Most superglues, you can only use them once before the glue itself plugs up the nozzle. I usually wait until I have a half-dozen things that all need gluing before I open up a fresh tube, because it’ll probably be useless the next time I need it. But occasionally, you’ll find a tube that can actually be re-used.
The ones that are applied with a small brush attached to the cap are better in this regard.
Dollar store super glue - four tiny tubes in a plastic pill bottle type container. Probably not the best glue, but seems to stick, and if I can’t re-open a tube, no biggie to pitch it and open a new one.
I’ve had the best luck by far with Gorilla brand superglue (their cyanoacrylate). Even after opened and stored in a hot garage for months it is still usable. All others I’ve tried are good for only a couple uses before clogging up.
ETA: The Gorilla CA is also a little thicker so it doesn’t run off like many others.
One difference between cyanoacrylates is the level brittleness. You will get additives that make the adhesive slightly more forgiving to shock. If you want the joint to be temporary this is a bad thing. For instance most people will have come across Loctite in one of its original incarnations as a thread locker. Sometimes you want to be able to later undo a locked thread, only wanting the lock to stop vibration loosening the fastener. Other times you really never want it apart again. You use a brittle glue formulation for the temporary lock, and a more resilient formulation for the permanent.
My impression (formed with no actual evidence) is that the cheap superglues don’t have any of the interesting additives, and are the simple raw brittle form.
I’m finding that certain cheap plastics don’t seem to take a gluin’. Is that because I’m using cheap superglue or the wrong type of superglue?
Some plastics have very low surface energy, and they simply don’t glue. There are two part glue systems that use a surface prep and then adhesive that will glue many of them.
Super-glues are definitely not all the same. Apart from the differences mentioned above, they also have different formulas to create larger or smaller “open times”, that is the amount of time after application that you can make a bond. They can also have different viscosities, from watery to gel-like.
One of the few times working for an adhesive company has helped me answer a question on the Dope!
Many cyanoacrylate glues don’t work well on glass, polyethylene and polypropylene. But there are special formulas that do work on these materials.
Hardening in the tube after opening can be mitigated by storing the tube in an air tight glass jar with a few packets of desiccant.