Investigate the science of sticking and joining

HARVEY’S MISSION

There are lots of ways to join things together; you can glue, nail, stitch, paperclip, tape, tie or fasten. But how do you know what method is BEST? In this activity, we’re going to test them all out, tabulate the results and see which proves to be the most successful.

You will need:

– A responsible adult

– Strips of thick paper or thin card

– String

– Nails

– Needle

– Thread

– A range of glues and pastes (make sure instructions are read carefully first)

– Stapler

– Sticky tape

– Sticking plasters

– Pins

– Paper fasteners

– A printed copy of the table, which you can find here or perhaps you could draw your own

GET STARTED

Step 1:

Use the various ways of joining two strips of paper/card as shown in the diagrams.

Step 2:

Test each join with a gentle waggle and pull. Then try a harder waggle and pull. Score each of the joins out of ten, according to the following criteria. Make notes to show your findings.

    • Did it really join? (Did it succeed?)

    • Does it waggle? Much?

    • Does it separate easily?

    • Does it spoil the things you joined?

 

Step 3:

Ask a friend to carry out similar tests. Compare your results. Which method proved to be the best? Can you explain why you think this was?

The home that gak built

If you enjoyed this experiment, why not investigate the various ways in which items have been joined around your home or school.

Some adhesives get into crevices while they are soft. When they harden, they make little interlocks. Putty, for example, hardens in the crevices round window glass.

Screws need a hole. They also have spiral ridges. These make good interlocks with the wood because the wood ‘gives’ to fit them. When a material like masonry is used, a rawplug is needed to provide the extra ‘give’. A staple, on the other hand, makes a hole and then bends over to make an interlock. When straightened, it pulls out.

Look at wooden chairs and tables to see what joints have been used to interlock pieces together. The best joins are a perfect fit. They do not waggle or start to wear.

Try making some jigsaws. Solving a puzzle is the perfect to way to see how interlocking pieces merge together to make a whole.

Level Up

Make your own carrier bag out of thick paper. Fix the handles on in different ways (See figure). Test them by placing metal cans into the bag to find out which handle fastening is the best.

Written by John Davis