super glue

4 Articles

Tech In Plain Sight: Super Glue

December 11, 2023 by 68 Comments

Many inventions happen not by design but through failure. They don’t happen through the failure directly, but because someone was paying attention and remembered the how and why of the failure, and learns from this. One of these inventions is Super Glue, the adhesive that every tinkerer and engineer has to hand to stick pretty much anything to anything, quickly. Although it was a complete failure for the original uses it was developed for, a chemist with good memory and an eye for a helpful product created it in a process he described as “one day of synchronicity and ten years of hard work.”

Super Glue was initially invented in 1942, when the chemist Harry Coover was working on a team trying to develop a clear plastic gun sight that would be cheaper than the metal ones already in use. The team cast a wide net, trying a range of new materials. Coover was testing a class of chemicals called cyanoacrylates. They had some promise, but they had one problem: they stuck to pretty much everything. Every time that Coover tried to use the material to cast a gun sight, it stuck to the container and was really hard to remove. 

When the samples he tried came into contact with water, even water vapor in the air, they immediately formed an incredibly resilient bond with most materials. That made them lousy manufacturing materials, so he put the cyanoacrylates aside when the contract was canceled. His employer B. F. Goodrich, patented the process of making cyanoacrylates in 1947, but didn’t note any particular uses for the materials: they were simply a curiosity. 

It wasn’t until 1951 when Coover, now at Eastman Kodak, remembered the sticky properties of cyanoacrylates. He and his colleague Fred Joyner were working on making heat-resistant canopies for the new generation of jet fighters, and they considered using these sticky chemicals as adhesives in the manufacturing process. According to Coover, he told Joyner about the materials and asked him to measure the refractive index to see if they might be suitable for use. He warned him to be careful, as the material would probably stick in the refractometer and damage it. Joyner tested the material and found it wasn’t suitable for a canopy but then went around the lab using it to stick things together. The two realized it could make an excellent adhesive for home and engineering use. Continue reading “Tech In Plain Sight: Super Glue” →

Hacking Broken Plastic Parts Without A 3D Printer

October 13, 2019 by 16 Comments

We’ve all encountered the odd plastic part that is broken and unobtainable. Sure, 3D printers can print big replacement parts, but sometimes you just need to rebuild a very specific piece. [AkBkukU] shows off a technique for doing just that using a process you could almost call manual 3D printing. We’ve seen baking soda used to cure cyanoacrylate glue before, but this technique uses it to build layers of glue that are apparently quite solid.

There’s quite a bit of nuance in the video below, but the basic idea is to put a pile of soda on one side of a piece of tin foil and a glob of glue. You dip the part in glue and then into the soda. Each time you get a little thicker layer of glue.

Afterward, you’ll have to file and otherwise shape the new part, but the fact that it can survive being filed should tell you something. We were reminded of how some people use epoxy to form repair parts and then machine them to the exact shape needed. At the very end of the video he builds up layers on a part he can’t dip. Did it work? Watch it and see.

In addition to the manual 3D printing technique, he demonstrates using baking soda to cure repairs on a knurled knob from an old clock radio. That’s a bit more conventional, but if you haven’t seen it done before, it is nearly miraculous.

Glue is amazing. We’ve seen hot glue do injection molding. There are many more types out there, too.

Continue reading “Hacking Broken Plastic Parts Without A 3D Printer” →

Saving Your Vision From Super Glue In The Eyes

March 8, 2019 by 72 Comments

Super glue, or cyanoacrylate as it is formally known, is one heck of a useful adhesive. Developed in the 20th century as a result of a program to create plastic gun sights, it is loved for its ability to bond all manner of materials quickly and effectively. Wood, metal, a wide variety of plastics — super glue will stick ’em all together in a flash.

It’s also particularly good at sticking to human skin, and therein lies a problem. It’s bad enough when it gets on your fingers. What happens when you get super glue in your eyes?

Today, we’ll answer that. First, with the story of how I caught an eyeful of glue. Following that, I’ll share some general tips for when you find yourself in a sticky situation.

Continue reading “Saving Your Vision From Super Glue In The Eyes” →

Homemade Bulletproof Glass, Built And Tested

January 28, 2016 by 35 Comments

Hackers tend to stash away lots of stuff that seems useless, right up until it saves the day. This includes not just junk in our parts bin but brains full of tips and tricks for the shop. With that in mind, you might want to file away a few of the tips in [AvE]’s video of how he made bulletproof glass for a rainy day.

By his own admission, [AvE]’s video is a little disjointed, and the topic of the bulletproof glass is only covered at the beginning and again briefly at the end. Most of the video concerns the machining of a stout stand for the glass for testing on the range. There’s plenty to learn from the machining, though, and [AvE] is always good for a laugh, so the video is worth a watch. The bulletproof glass itself is part of a long-term project that [AvE] is releasing first to his Patreon patrons – a ridiculously over-built flashlight dubbed “The Midnight Sun”. His first two tries at laminating the Lexan discs were less that optimal, as both brands of cyanoacrylate glue clouded the polycarbonate. Stay tuned to the end of the video for the secret of welding Lexan together into an optically clear sandwich.

As for testing under fire, [AvE] sent the rig off to buddy [TAOFLEDERMAUS] for the hot lead treatment. The video after the break shows that the glass is indeed bulletproof, as long as the bullet in question is a .22LR. Not so much for the 9mm, though – that was a clear punch-through. Still, pretty impressive performance for homebrew.

If you want something that can stop an arrow, there’s a lot of materials science to be learned from the ancient Greeks.

Continue reading “Homemade Bulletproof Glass, Built And Tested” →