I remember when Krazy glue first came out…it was great. Now, it doesn’t seem like so called super glues work at all. I have tried various brands, and have trouble glueing a plastic cup. Were there too many lawsuits from kids glueing their eyes shut?
Too many people were using Krazy glue when just ordinary glue would do. Plastics evolved to be Krazy glue resistant, and there is a move to make Krazy glue prescription only. 
you need to make sure you’re using it properly. CA glues cure when squeezed into a thin layer. you need to apply a small amount to one of the surfaces you’re joining, then hold them together under pressure for a short time for the CA to “kick.”
also the thin CAs seem to work faster, gel-types cure slower in my experience.
It sticks better if you blow a humid breath over the substrate before bringing the two sides in contact. Water vapor is involved in curing. That’s what I read and it seems to help. For me, epoxies rule.
CA’s work great in some applications. But not so well in others.
On a failure analysis project at work, I discovered the root cause was the use of a CA adhesive used to bond two critical components together. The system was being used over a fairly wide temperature range, and the CTE and Young’s modulus of the CA adhesive were very different than the other two components (primarily the Ym). The results were disastrous, literally. In a nutshell, the CA adhesive was *much *too brittle for their application, and we recommended using an adhesive with much more compliance.
In addition to the above comments.
CA (Cyanoacrylate) is pretty brittle and has very low sheer strength. That makes it undesirable in many situations. Gluing a chip back into a cup would be fine. Gluing the whole handle back on might not be (esp with a cup full of hot liquid).
By the by, CA reacts exothermically (it gets hot. Really hot) in contact with some things like cotton. I’ve used it on the lathe as a finish for things like pens and paper towel + friction + CA = burnt fingers. It was hilarious for the on lookers as the paper towel still sticks to your finger just fine as it burns it.
I use the thin stuff most of the time. I find the prepacked little tubes to be the worst at gluing (confirming your finding)
Ahhh…The power of advertising mixed up with the power of nostalgia and the inaccuracy of the human memory,.
What, the part about gluing eyes shut?
Tell that to Prince Frederick von Anhalt, hardly a kid.
(Of course, if I were married to Zsa Zsa, I’d probably glue them both shut.)
CA glue is still CA glue. What does gluing one’s eye(s) shut have anything to do with the matter at hand? Well, current CA glue poses the same risks as the old stuff. So, my comment has been bolstered by your comment, postcards. Thank you.
So… It is the power of advertising mixed up with the power of nostalgia and the inaccuracy of the human memory (oh, it was so much better back then!). See, one might remember the ‘old’ Crazy Glue as being superior to current CA glues. Current CA glues can glue eyes shut, just like the good ol’ fashioned ones from the old days.
.
Sadly, this is proof that you can’t protect people from themselves!
Now that’s funny!
My beef with super glue is it seems like I can use it only once, then I have to throw the tube away. No matter how carefully I try to seal it, the whole damned thing has turned rock solid by the next time I get it out. Fortunately, the stuff is cheap here, 25 baht (80 US cents) for a small tube.
Even in the old days I never found super glue to work on plastics.
My current favorite glue for non porous (and porous) surfaces is Weld-Bond, it can glue glass to glass and I’ve used it on plastics to other things but never plastic to plastic.
How many times a year do you use it? If it’s only once or twice a year then my suggestion won’t make sense.
But if you have to use it more than once or twice a year you might want to paradoxically invest in a larger container of CA glue – one that stands upright instead of in a tube. It won’t dry out in a year. If the regular stores don’t carry it, try a hobby or gaming shop. It runs around $8 (although would probably be cheaper if found in a department/discount store), which wouldn’t be cost effective for you because it will still dry up before you use it all, BUT it might be worth the hassle of not having to rush out and buy more CA glue every time you need it. The big container can also appear be stuck but that can be fixed by poking it with a bent paperclip or a tack.
Plastics are notoriously hard to glue. There are all kinds of different adhesives that are specific to the type of plastic in question; IIRC it’s because they aren’t affected by the same types of solvents.
Nah, a couple times a year is about it. The little tubes we buy come with a long straight pin to poke it with, but really, it’s like trying to poke through granite. Never seen larger tubes over here, but no doubt we could find it if we tried. But we’re never caught short, because we usually keep two or three on hand, since they’re so cheap. If the old one’s dried up like usual, just open a new one. They sell them in grocery stores.
I have a dollar store right next door to my office and I can buy a package of 2 super glue tubes for a dollar. The glue works fine but the tube and nozzle leaks everywhere. I’ve come to accept that they are one time use kind of thing.
I’ve found that Loc-Tite Super glue works well and their epoxy with spray activator/hardener is fantastic.
Thanks for the safety tip. I was going to try the CA finishing technique this winter. Although I was planning on using gloves.
it depends on the type of plastic. it seems to work OK on, say, polystyrene or ABS. But there are some plastics that no adhesive seems to want to stick to, like polyethylene or polypropylene.
You can store it the fridge. It’ll last longer (plus there is probably less moisture in your fridge). It doesn’t take long for it to thaw out. Those little tubes are still a pain though.