Wiki

This page covers sticky tapes and glues.

Summary

When things fall part there are various types of glue and sticky tape that you can use to stick them back together again, but different ones are good for different things. This page will help you choose the right one.

Safety

Broken mains electrical items repaired with adhesive and/or sticky tape will necessarily fail the visual inspection part of a PAT electrical safety test. If you decide on such a repair (at your own risk) you should at least ensure that any glue is supported by strong tape such as gaffer tape wrapped completely around the item, with a good overlap.

Types of Glue

There are lots of different types of glue. The first few below are the most useful in a Restart situation but others may come in handy for general repairs or for making stuff.

Superglue

Superglue will stick your fingers together instantly. You may find it rather embarrassing to have to go to A&E to get them unstuck.

Provided the surfaces to be mated fit together very closely, superglue will usually do a good job, but it's not so good at filling gaps. Buy it in small tubes and make sure you put the lid on tight as otherwise it will set solid.

Epoxy

Epoxy glue comes in 2 separate tubes. Squeeze the same amount from each tube and mix well. Be sure to put the right lid back on the right tube, or you'll never get them off again!

Epoxy glue sticks to most things, and although it's best if the mating surfaces fit well together, you can use it to fill gaps or build it up around a join to add strength.

Rapid epoxy sets in a few minutes and so is very useful, though it takes longer to achieve full strength.

Hot Melt

Hot melt glue comes in sticks which you have to feed into a glue gun. Cheap glue guns are available for just a few pounds. Apply the glue and join the parts together immediately. The glue will set in a few seconds as it cools but will take a little longer to gain full strength.

Hot melt glue remains flexible after it has set and so is good for repairing flexible things, like sticking the sole back on a shoe. Where a wire is soldered to a circuit board a blob of hot melt glue is very good for preventing the wire from flexing and breaking at the solder joint.

PVA Glue

This is mostly used for wood. The strongest joints are screwed and glued.

Vinyl Adhesive

This is good for sticking PVC as it consists of PVC dissolved in a solvent, which will partially dissolve the surfaces to be joined.

Glass Bond

This is a UV-cured adhesive which is good for sticking glass, transparent acrylic or metal to glass or acrylic. If you don't have a UV lamp you can cure it in sunlight, though it will take considerably longer.

Polystyrene Glue

Mainly used for assembling "Airfix" and similar plastic models, but also for paper.

Sticky Tapes

PVC Tape

PVC insulating tape is good for wrapping around exposed wires and electrical connections, however, it should never be use as the sole protection in the case of mains (or higher) voltages. If two wires are simply twisted together, heat may be generated when a current flows and this could melt the tape. (Use solder or a crimped or screw-secured connection.)

PVC tape sticks reasonably well bit it's stretchy and not especially strong, so shouldn't be used simply for fixing.

Gaffer Tape and Duct Tape

These are very strong tapes used for holding things together. Gaffer tape has a fabric backing whereas duct tape uses some form of plastic, but otherwise they are similar and often confused. Good for taping cables to the floor to prevent a trip hazard.

Self-amalgamating Tape

This isn't strictly adhesive, but when wrapped around an electrical junction or low pressure water pipe the layers fuse together seamlessly.

Sellotape and Scotch Tape

These should only be used for paper and parcels.

Other Sticky Stuff

Sugru

Sugru comes in sachets and initially has a putty-like consistency but cures to a synthetic rubber. Excellent for adding protection and strain relief to a low voltage cable (such as a headphone lead) where it's starting to crack on its entry to the plug. The website www.sugru.com gives hundreds of other examples of its use. It comes in black or white and several bright colours.

A drawback is that part used sachets cannot be resealed and will very quickly go off, and unused sachets have a limited shelf life. This can be extended somewhat by keeping them in the fridge.

Formcard

A thermoplastic which comes in credit card sized pieces which can be softened in hot water as required. It can then be moulded for a variety of uses before it sets hard on cooling. It was launched in a Kickstarter campaign in late 2015 and should subsequently be available more widely.

Modelling Clay

There are several types of modelling clay, mostly used for making rather than repairing. Polymer clay can be cured by heating to a modest temperature of 13⁰C for 15 minutes and doesn't shrink or change shape in the process. It can be obtained from hobby, craft and art stores.