Lash extensions are applied with an adhesive called a cyanoacrylate. Lash adhesives are made from methyl-2-cyanoacrylate which is designed to bond a smooth surface (the eyelash extension) to a porous surface (the natural eyelash). It is designed to be used around the eyes and on the natural lashes, but not on the skin which will cause irritation.
There are a variety of Cyanoacrylate adhesives designed to have curing times designed to accommodate different skill levels and speed.
- 1 to 2 seconds – Expert
- 2 to 5 seconds – Intermediate
- 8 to 10 seconds (Sensitive) – Beginner
Speed Diva Lash Adhesive is designed to be an adjustable adhesive. Meaning; the more control over the environment of your lash studio (temperature & humidity), the better you can control the open time (or cure speed)! Optimal temperature 21 to 22ºc.
- 15% to 25% RH: 6 to 8 seconds open time
- 25% to 35% RH: 4 to 6 seconds open time
- 35% to 45% RH: 2 to 4 seconds open time
- 45% to 55% RH: 1 to 2 seconds open time
- 55 to 65% and higher RH: less than 1 second of open time
Light Speed Lash Adhesive is also designed to be an adjustable adhesive, however it is a little more forgiving with higher humidity environments. Optimal temperature 21 to 22ºc.
- 15% to 25% RH: 8 to 10 seconds open time
- 25% to 35% RH: 6 to 8 seconds open time
- 35% to 45% RH: 4 to 6 seconds open time
- 45% to 55% RH: 2 to 4 seconds open time
- 55 to 65% and higher RH: less than 2 seconds of open time
The following excerpt from “Understanding Adhesives” Classic 101 – Core Skills Application Pro:
As discussed, your “Open Time” is determined largely by the quantity of hydroquinone used in your adhesive however almost any adhesive can be “adjustable”. Meaning; you may be able to increase or decrease the cure speed of your adhesive by changing the humidity and temperature in your studio.
In order to determine what changes need to be made to your environment you will need to have a hygrometer on hand. This way you can record the temperature & humidity prior to every appointment. This is the best way to determine what works best for your environment as well as reveal your clients unique cycles. (Please see Lash Consultation Pro Mini-Course for more details on consultations and tracking your clients progress)
You are experiencing difficulties with retention – or – the adhesive seems gooey or stringy as you dip the extension: Your adhesive cures to fast, resulting in bond resistance or bond failure, because the adhesive is mostly cured as you bring the extension in for bonding to the natural lash. What you can do:
Lower the RH (relative humidity) in the studio.
- Turn on HVAC and/or a fan to increase air circulation.
- Run a dehumidifier in the room.
- Open a window (if the RH outside is lower than the inside)
- Heaters and A/C units may contribute to the humidity and may be adjusted or turned off. You may want to use a small space heater in your studio as an alternative to forced air heating.
Lower the temperature in the studio
- In this case you may want to turn on A/C units (keeping an eye on whether the humidity changes)
- Open windows strategically to allow for a gentle cross-breeze to flow through your work space.
- Turn on fans. Ceiling fans should be turned to spin counter clock-wise to push air down.
You are experiencing difficulties with sticky’s – or – the adhesive doesn’t “grab” the extension so you have to hold it in place for a long time before the extension seems to grab onto the natural lash: Your adhesive is not curing fast enough. What you can do:
Increase the temperature in your studio
- Ceiling fans should run clockwise to pull air up and redistribute the hot air that rises to the top of your room.
- Optimal temperatures are normally between 21 to 22 degrees however you might like to experiment by increasing the temperature by half a degree at a time until the adhesive starts to dry down a little quicker.
Increase the humidity in your studio
- Run a humidifier or 2 in your studio.
- Use a Nano-Mister frequently during the course of the lash appointment.
- Opening a window may be all that is needed if the RH outside is higher than inside.