On carefully unscrewing screws from aged plastic, for example onice Italian portable organs or keyboards

At your risk.
Take all safety precautions.
Do not attempt if you are not thoroughly familiar.


If the screws feel like stuck, jammed, they probably are after all those years. Plastic may have also become too hard or brittle.


The plastic threads may easily break when this quick unlocking sound is heard.


A way to avoid this happening is gently heating up the stuck screws with a soldering iron. Take great care for temperature and how low as the plastic may even melt.


If it is done properly by experience the screws will unscrew smoothly like butter.


By the way from little experience on Italian EKO keyboards, they would be will keys facing the ceiling when trying to open them.


What to do if plastic is broken?
(At your risk)
Thermal glue seems to give better results than expected.
And it can be easily removed with methylated spirit.