The one you know how to work with! Let's talk about getting to know that one thing that can make or break our day/week/month/year:
Eyelash Extension Adhesive.
It's a tricky subject.
But we just dip the extension in it and stick them to the Natural, right? Noooooot so fast there. We need to use the science behind these glues to truly understand them and create an environment around them that is mutually beneficial.
Cyanoacrylate-based adhesives on the market vary greatly from Instant Bond Glue such as Super Glue and Krazy Glue to Lash extension glue to Dental glue to Surgical glues and more.
There is so much science that goes into each and every one, but there seems to be a lot of debate as to what that science says for the lash world, specifically. So let’s dig in!
Cyanoacrylate (Ethyl- Methyl- and Ethyl 2-) bonds almost anything instantly as long as there is at least a small amount of moisture involved.
When moisture is introduced to the liquid adhesive the glue will start to polymerize (harden) and cure, due to that exposure. As it cures, it ideally wants to stick a non porous item (extensions) to a porous one (natural lashes). It releases small amounts of fumes in the form of both Formaldehyde and Acetic Acid. It's fumes attach to moisture and alcohols and can form a film on them (did you know that heated cyanoacrylate is used by investigative teams to lift fingerprints?) meaning they can attach to skin & mucus membranes. This can potentially cause irritation when used in large amounts or consistently in one area - including our respiratory system, nasal passages, and eyes. MSDS reports state that eyes, nose, and mouth should be protected while in use. (By wearing glasses and carbon-filter or VOC-specific masks) The strength of the fumes varies depending on how it was manufactured (read: QUALITY), how quickly it cures, what it was created to do, and how long it has been open. It always must be treated with the safety guidelines, no matter who produced it or where it was created.
Opened bottles of cyanoacrylate based adhesives (that have been exposed to the environment, also therefore, moisture) will typically work for 6 to 8 weeks before the remaining adhesive polymerizes itself.
HOWEVER, after 4 weeks of being open your glue may not bond the same way it did before due to the moisture that has been introduced to the glue in the bottle. After being opened and exposed like this it will start to degrade. Most lash glues are only safe and good to use for 4 to 6 weeks (tops!) before they expire and will not only start causing retention problems, but also irritation, by producing more fumes as the degradation process continues. Moral of the story? Chuck it after 4 weeks and open a new one. Your future self will thank you!
The temperature we store and work with eyelash extension adhesive needs to be taken into consideration as well.
As temperatures rise above the ideal range (68 to 73° F, 20 to 22° C) they tend to get stickier and dry/cure faster.
As temperatures dip below the ideal range, they have a harder time curing as quickly as needed.
Sometimes this can work to our benefit. Often if we can’t adjust our humidity conditions immediately, we still have the opportunity to balance things out a bit.
Humidity too high?
Lower that temperature. Not only will that help to remove some of the humidity but the cooler temperature will give you a tad bit more time to work with your adhesive.
Humidity too low?
You can raise the temperature in your room by a few degrees to help compensate for it. This part is not an exact science, rather abalancing actto help you out during unfavorable conditions.
So how does this play into what we really want to know about: Eyelash Extension RETENTION.
Well most of us know we have to control our temperature and humidity to have our glue work properly, but you can’t base the glue you choose solely on what your average humidity. In addition to environmental conditions, how you personally work with your glue matters - a lot. How quickly you work needs to be considered in conjunction with your particular technique, application, and fan attachment process.
It really can be a trial and error process to figure out what glue works best for you. Often you’ll find yourself favoring a different adhesive as seasons and environmental factors change.
My personal advice to you?
Set about gathering intimate knowledge about many eyelash extension glues. Learn how to observe them, what properties change about them when you use them in different circumstances, and how to personally adapt how you are working so you can work together instead of fighting with each other. When we know all these things and take the time to experience them, we’ll find that humidity is just one important factor in what glue we should choose. I like to teach students to "Get a hygrometer, then learn how to ignore it."
There are some simple steps you can take to improve your eyelash extension glue:
Pay attention to your humidity - you will likely base the adhesive you want to use around those average numbers.
Watch your glue as you use it. When it's wet (looks shiny) on the end of your lash or fan, we are able to continue to attach, work with it, & manipulate it. When it's cured (dry/ looks matte) we can't manipulate it & shouldn't try to attach it to anything. It just won't work. (think about the difference between sticking something together with super glue vs. tape) SOOOOO
Glue should be wet when we move it over to the natural lash, and apply it. If it is wet the whole time & then turns matte as you hold it on the natural lash, that is ideal!
Glue that turns matte before it reaches the natural is curing too fast. You have 4 options: Work FASTER (& know this isn't always possible), Use slower drying glue, use a dehumidifier, or lower your room's temperature.
Glue that stays shiny & wet after application isn't curing fast enough. You have 4 options: Work SLOWER (again, not always possible) Use faster curing glue, apply Glue Aid to lashes to speed the dry time, use a humidifier, or up your room’s temperature.
Let’s just be clear about one thing: I'm not saying that you personally have to work faster or slower to make your glue work for you, just that it's one option among others! What I want you to take from this is that your environmental conditions are so important, but only play a part. The rest is how you personally work, and how you choose to work with them!
LBLA in their curriculum provides save and effective way to work with lash adhesives.
Anything outside prescribed usage could be potentially dangers. Following proper product usage and having proper certification will eliminate risk to minimum.