Super glue -- What is it? How does it work? Precautions?

We use super glue for many things in kite and banner making, such as attaching vinyl end caps and ferrules to our spars. But what is it? How does the stuff work? What precautions should we take?

What is it? It is ethyl 2-cyanoacrylate (CA). It is typically composed of about 90% ethyl 2-cyanoacrylate and 10% other compounds with traces of an organic acid. Thinner glues are most likely primarily CA.

Super glue bonds all kinds of materials but does not work well on the super smooth surfaces, like glass.

How does it work? Super glue is different from most glues we work with. White school glue and yellow wood glue are water based. You apply and the water evaporates. Super glue is just the opposite. It actually cures with water. It draws water from the air or the surface of the items being glued. Curing is caused by water vapor on the surfaces or in the air. (Most all surfaces have some water from the surrounding air, therefore humidity can affect bonding.) Super glue contains its own hardener. They add a weak acid to inhibit the bonding action from starting (keeps the molecules apart). When the moisture gets into the super glue, it dissolves the acid and triggers the curing process.

Super glue bonds quickly when spread very thinly between two surfaces. This is most often done by pressing the two surfaces together. Curing starts at the surface and progresses to the center on the glue. If applied too thick, the center may never cure. So, super thin is super for super glue.

Apply a small amount, like one drop per square inch. It usually cures in 30–60 seconds. You can handle your item in 1-5 minutes and a complete cure takes up to 24 hours.

Super glue is at its best holding things that are trying to be pulled apart. It is not the best at shear strength, like twisting and side-to-side forces. It also can crack/shatter if hit by a blow or dropped.

What brand do I prefer and why. The brand I use most is Gorilla Super glue in the half ounce bottle with the baby blue top. You can find at Home Depot, Lowe's, WalMart, etc. Super glue can be brittle. Gorilla adds rubber particles that enables it to better absorb shock. The Gorilla glue is not thin and runny like some of the other super glues. It also seems to to have a longer self life.

Problem solving: One of great things about super glue is that it bonds quickly. But sometimes it does it too well, like when you slip the ferrule into you spar and get only a half inch in and it will go no further. At times it just bonds too quickly.

Remember how above we talked about how super thin is super for super glue. Well if you have enough space between the parts and use a thicker layer you slow the curing time and you can adjust the parts. Once all is aligned, press the parts together to thin it out and to get them it to instantly bond. (No need to clamp.)

The instant setting if the glue before you can get things positioned is often due to the parts being too tight. The spars and ferrules we use are not the most precisely dimensioned. If they are too tight, try a different ferrule or put it on a different spar. Often that will work. If needed, sand the ferrule down, just a tad, to give you a little more space. It needs to easily slide in and out. If you have to push hard, your super glue is most likely going to set up before you get it positioned.

So you want it to cure even faster? They make what are called accelerators which you can spray on the glue and it will set up instantly. You can find at any hobby store that is into model building and radio controlled planes, cars, boats, etc. Pouring baking soda over the glue will also cause a faster cure but colors the glue white and can have an uneven texture.

How do you fill a void with super glue if you are only supposed to use in super thin layers? Baking soda to the rescue again. Drop in the super glue and pour the baking soda on top. They combine and harden. You'll need to do in layers if the gap is very deep. If you pour the baking soda in first, the super glue will immediately combine with the top layer and not soak in. It does not make a smooth surface and it will be the white color of the baking soda. You'd have to sand after.

The advantage of using super glue as a filler is the lack of shrinking.

Health Warning… Super glue has a strong, acidic odor. The fumes may irritate your eyes, your lungs and everything on the way there. For some people, or people who have exposed themselves many times over the years, the fumes may cause chronic allergic reaction. So protect yourself now, so you can use super glue throughout your life time.

Super glue will bond the skin. No joke, your fingers will be stuck together. Remember never to touch your face while working with it, especially around your eyes.

In skin or eye contact, super glue is non-toxic, so don’t panic. Carefully assess the situation. Seek medical help if necessary. Never try to tear the apart the bonded body parts!

Super glue can rapidly cure if exposed to a lot of water or alkaline substances and create a lot a heat, enough to inflame or even burn skin.

The bottom line is it is best to wear safety glasses and breathing masks. Not the thin masks that just keep out dust. If you can smell it, the mask is not keeping the fumes out of your lungs. To be truthful, if I am just doing a few ferrules, etc, I do in a well ventilated place keeping my hands and face away from the glue. I also use over some old newspaper to catch any glue drops and as a way to wipe off any glue that could ooze out as I insert, like a ferrule, for example. I then set aside with the glued end hanging over a small board to keep the part from gluing to the paper. I’ll often use the form fitting Exam Gloves, yeah like the ones your doctor uses. You can buy a box at Costco, etc and use them for all kinds of stuff (Come in latex and non-latex versions.)

Good ventilation is always a must.

"Well, I goofed. How do I remove it from my skin?" My experience is if you get a little on your fingers you can often carefully peel it off. Mostly, I leave it alone. It will magically come off on its own anyway in a day or so anyway.

You can soak a bonded area in warm soapy water. If you get desperate, use finger nail polish remover (which is diluted acetone) or even acetone straight. (Remember, be it acetone or super glue itself, your body absorbs substances though the skin. I try to stay away from it unless absolutely necessary.) You must be patient and NEVER pull the bonded areas apart. Gently wiggle the area to work the soapy water into the bonded area. If you were crazy enough to get on your lips, don’t panic. The enzymes in your saliva with help break down the bond over time. Be patient. Just take it as a sign that you talk too much.