Van der Graaff: tips for successful sparks
The Van der Graaff generator is a staple experiment in almost every school and the basis of every static electricity introduction. From sparking in air to raising the hair, the Van der Graaff is always a winner with students.
But…’Lord or Lady’ Van der Graaff can be somewhat vain in temperament and will often need an ego boost to perform to their best (as all the best stars of the show do!).
If you have been dreading the request of “Van der Graaff” on your order sheet, for fear it will embarrass you (again?), then try these tips to keep that ego soothed and ready to perform on the main stage.
Remember: keep it safe and discharge and unplug before starting maintenance work. All the best performers can be a bit prickly when told they need sprucing up – don’t let this diva bite!
Tips to keep the Van der Graaff in top shape:
- Humidity: This diva does not like to perform in the wet (who does?) or even the slightly damp. Have a hairdryer on hand to dry the air immediately around the generator if you think the weather is a smidge on the damp side (which in the UK is most days). Just don’t heat it for too long or too hot or too close as this will damage the generator (did we mention this one is a diva?).
- Dome: Make sure the dome is (pretty) smooth. Like most stage performers this one loves the skin to be smooth and glowing. Remove the dome to gently knock any (large) dents out, and smooth off any nubs with fine sandpaper before drying with a soft lint-free cloth and wiping over with methanol (allow to evaporate off, beware methanol is toxic and flammable).
- Clean: With the dome off it’s time to spruce this performer up with a clean. Carefully remove any build-up of dust etc. in the combs and on the belt with a soft cloth. You can wipe the support (insulating) column and the rollers with a lint-free cloth and wipe them over with methanol as you did the dome.
- Collector comb: It doesn’t want to be touching the belt, a distance of a few mm will allow for good charge collection.
- Belt: You may need to remove the belt and replace it if it is old or loose, wipe the new one down – soft cloth and methanol as before - before fixing it onto the generator. Make sure it is not too tight once fitted (you can gently stretch it before fixing, but don’t overdo it. Lord Van der Graaff does not like a loose waistband on his costume!).
- Lower pulley: Check that the material (unless it's Teflon) on the lower pulley isn’t damp or flat. A touch and remove with a strip of Velcro will raise the fibres again for better flow of charge. If the bottom pulley is Teflon, wipe it with a soft cloth.
- Both pulleys: After cleaning these will need a little lubrication (back to the green room anyone?). A little dab of lightweight bearing grease may be needed if the Van der Graaff you have has pulleys with bearings (you may need to check the instruction manual).
- Storage: when not in use (or ‘resting’ as our performers like to say) keep the Van der Graaff in a dry place and covered to prevent any dust build-up or damage to the dome (no performer likes a damaged hairdo!).
- Need Help? For help and instructions for removing and replacing the belt follow this link click here
Follow these tips for a flawless performance every time...