Repairing broken plastics? This stuff is better than superglue

Broken plastics are a fact of life these days. Plastics tend to break either through being dropped or misused, or through old age.

My weapon of choice in the war against waste and sending things to the landfill has been cyanoacrylate adhesive — this stuff goes by many names, such as instant glue, power glue, or superglue — and on the whole it's pretty good stuff.

But it's far from perfect.

I find the performance of cyanoacrylate adhesives varies a lot. It sticks well to some things, but not so well to other things. Also, its repairs last well at room temperature, but using it to repair something that's going to be in a hot environment (such as a greenhouse) or cold environment (such as a refrigerator) can be disappointing.

And after decades of using cyanoacrylate to repair stuff, I'm still wary of it. It gets everywhere, and while its performance might be subpar on some materials, you can be certain that there's one thing it sticks to really well, and that's human skin.

And you definitely don't want to get superglue in your eyes.

A few people have mentioned that I should try UV curing adhesive for repairing things, so the other day I gave it a go.

And I'm impressed.

Note that the kit I'm recommending comes with a small UV light, so you don't need to worry about buying that separately.

Unlike cyanoacrylate where you apply the adhesive and you have seconds to work before it cures, the UV resin doesn't cure until you apply UV light to it, so it gives you more time to work.

Curing UV resin with a small UV light

Curing UV resin with a small UV light

Also, because the resin is thicker, you can use it to build up the repair better and more easily than with cyanoacrylate (you can add some baking soda to cyanoacrylate to achieve the same result, and it does make for a stronger bond, but again it can get messy).

UV resin also eliminates you accidentally gluing your face to whatever you're repairing. Don't think you can suddenly find your face glued to something? Think again.

I've experimented with UV resin adhesives on a number of different materials, with impressive results. It seems to work much better for repairing things that are going to be subjected to heat and cold, and it's great for building up material when something has broken when the plastic has shrunk (which happens over time).

One drawback is that UV resin relies on UV light to cure, so wherever you apply it, you will need to be able to get the light on it to cure it. Bear this in mind as it makes it unsuitable for some applications.

For example, if you're sticking something down, adding the resin underneath isn't going to work because it won't cure. 

But overall, I'm impressed. It doesn't fully replace cyanoacrylate adhesive, but it's another tool in the toolbox.

And it's fast become an indispensable tool.

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