Can super glue lose effectiveness after awhile?

I've got some Zap A Gap super glue that I tried to use on a thin part, and it didn't stick. I've had it for a while, but it's still very fluid, because I made sure to wipe off the tip to let it seal good. I don't know if it was the part or if the glue can go bad. I get contrary advice through Google with some saying that it can expire, though there's no expiration date on mine.

I would think if your bottle is still liquid, then there's still cyanoacrylate in the bottle that is capable of making a bond. If it is an old bottle, and some of the of the CA has polymerized, making the liquid a little thicker, then the bond would take longer and might not be as strong. In the link below, it talks about how CA becomes solid in contact with water, so maybe humidity is an issue with your case? Or perhaps you're being haunted by a model making ghost?

And if super glue has an expiration date on the bottle, I'd think the end result would be a solid block of CA within the bottle, not a liquid that doesn't work any more.

Interesting to read (to me at least): https://supergluemsds.com/Docs/PT-0...PT-05, PT-80 - Zap-A-Gap - Rev. 17 - 2014.pdf

It gets less effective with age once opened. I've heard of people extending the life by putting it in the fridge (sealed inside a bag of course to prevent fumes from getting out).

After it's been open for a while, you'll notice it starts taking longer for the glue to "grab" and this only gets worse. This is why I buy only small bottles to prevent it from going to waste.

Yes it definitely looses effectiveness as it gets older. At work we store in a refrigerator, like star-art says.

Thanks, I'll guess I'm adding new glue to my list.

It also doesn't age well after it's used and cured! Gets brittle. I try to avoid it.

Some things it doesn't stick to as well, you can use the insta-set to make it cure if you want.

Treadwell said:

It also doesn't age well after it's used and cured! Gets brittle. I try to avoid it.

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Yeah I'm going to experiment with liquid glue (the styrene-styrene weld stuff) on my next build. I used super glue on my Chiss Fighter and I'm worried about finding it in a pile sometime!

Sluis Van Shipyards said:

Yeah I'm going to experiment with liquid glue (the styrene-styrene weld stuff) on my next build. I used super glue on my Chiss Fighter and I'm worried about finding it in a pile sometime!

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If I'm building a styrene kit, I use styrene weld exclusively.
It melts and bonds the plastic together, making for a stronger join; it doesn't get brittle with time; it's easier to sand/file/shape than CA, which to my mind is the modeling equivalent of shaping stainless steel; no heart-stopping panics when you drunkenly glue your fingers together.
I only use CA when I absolutely have to - like for PE or nylon bits.

I've experimented with what I have (I think from Plastruct). I held the pieces together and let the glue flow between like it says, but it always seems to just glue the edges, not spread across the entire width of the part. It was easy to pull apart.

I don't like that thin "capillary action" glue, either.
I still use the old Testors orange tubes.
For fiddly bits, I'll squirt some glue out on a scrap of cardboard and apply it with a toothpick.
I'm old-school.

All glues become defective over time. I used paint thinner because that melts the plastic and so it worked like a weld, but that broke clean of later on. Model glue becomes weak over time too, of course not when you want it i.e. when you want to salvage an old kit.

RKS.

I'd say some research is needed. Liquid "glues" for styrene come in all kinds of formulations some specifically for certain plastics and hence unsuitable or less suited for other types. I've found that the original Testors liquid solvent in the glass jar was quite good for your standard run of the mill polystrene kits. Their tube cement was the same with a thickening agent added which I have not used for a long time due to issues with precise application. I believe Testors has changed their formula to be less "hazardous" and in response to EPA regulations, and perhaps for other reasons. I've adopted the Tamiya extra thin as a fair replacement, but it is 'hotter' so it evaporates faster & provides for a less 'deep' weld, making application more challenging (Testors is still a good choice for a less hot solvent though it seems to lack the "punch" of the original formula...)

It is always good to keep in mind some basic characteristics for the available 'glues'. On one hand, you have the various solvents designed to chemically weld the parts together, which implies care is needed to ensure compatibility with the materials being used. On the other, the various 'cement' types (CA, epoxies, PVA, etc.) that work by mechanical adhesion between the parts by forming a rigid or semi-rigid matrix at the mating surfaces. For CA, the bond strength is greatest is tension while being relatively weak in shear, so for example, gluing shafts that have to resist torque is inappropriate So good resistance to "pulling" but bad resistance to 'sliding'. Its main use is for quick bonds between dissimilar materials that have some "tooth" or micro roughness on the surfaces (which is why your PE parts should be 'pickled' in an acid before use...) The set time will degrade with time as noted, but even aged CA can work within a micro-matrix field such as provided with micro balloons, paper or even baking soda (if the chemistry is confirmed first.) (CA alone is a poor gap bridge material as it performs best in tight fits.)

Performance of a bond over time is subject to many factors. CA is especially sensitive to weakening when subjected to repeated shear stress, for example when different materials result in thermally induced movement. Epoxies tend to be quite strong in all bond planes and some are slightly flexible as well which helps prevent debonding.

This just scratches the surface of what is really a quite involved subject. Most folks have a relatively narrow range of bonding requirements in their modeling and so settle on what they find works for them. This is not a bad thing, but one should be aware of the limitations of the 'tried and true' approach when trying new things or techniques, or working with new materials. One tip is to use the molding trees to test the compatibility of your modeling materials. Taking time to conduct some experimentation can save on grief later. It does take time however, because allowing for full cure can side track things a bit yet with the benefit of having confidence in the findings.

Even careful checks are not absolute proof against problems, as I found one time when the blob of modeling clay I used as a nose weight managed to melt its way out of my model after a couple of years! (Turns out it was a petro based product - like styrene.)

Hope this is of some use...

Regards, Robert

I just want to congratulate everyone who spelled "lose" correctly.

I used the correct form of there as well. :lol


I think the thing that wins me over with super glue is you can set it instantly. I'm not sure what the set time is for glue like the Plastruct Bondene I have. I just read something (while looking up which type I had) that said you can use the brush and coat a whole part, and while it will look/feel dry, it will still bond when the pieces go together. So it looks like I will do some experimenting with it.

As a professional model builder, time is of the essence. CA is essential. When I'm building for myself, I prefer welding my plastic parts together. The bonds are much stronger that way. It all depends on the materials involved. CA definitely has a lot of really good uses.

I typically use Tamiya's extra thin cement, and I've never had any "flow" issues with it before. I also use CA in a pinch.

SB

That's what I do.......On a long seam I coat the parts first with either Plastruct or the regular Tamiya liquid cement (it's thicker than the Tamiya super thin and doesn't dry as fast) join the parts....tape or clamp them. Then with a fine brush and go over the seam with the Tamiya super thin cement which wicks into the seam and reactivates the cement that was applied earlier. If you apply with very light coats it dries very fast and will hardly mess up the plastic. A light sand will remove any of the glue residue. Works really good in welding the seam. If I have access to the inside part of the seam I may go over it with epoxy or CA

Sluis Van Shipyards said:

I used the correct form of there as well. :lol


I think the thing that wins me over with super glue is you can set it instantly. I'm not sure what the set time is for glue like the Plastruct Bondene I have. I just read something (while looking up which type I had) that said you can use the brush and coat a whole part, and while it will look/feel dry, it will still bond when the pieces go together. So it looks like I will do some experimenting with it.

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You can also use CA as a "clamp" to hold your plastic parts together while the solvent cement dries. This can be very helpful when you're in a hurry!

Yeah it can get less effective with age but usually by thickening. Keeping it in a fridge as others have said slows this down.
Some cyanoacrylate does just seem worse than others though, even in the same viscosity.
The biggest problem with superglue ageing is brittleness, things will never fall off sitting on a desk or a shelf but if they're constantly travelling it's a problem.
I use it all the time just for time constraints, plus by the time it's starting to fail my works usually in a skip somewhere.

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