Hi. I'm 4 months into my second year and have been working on a totally new technique. It's still not clear whether it will work and I'm worried that after 18mnths I'll have to drop it. Does this often happen? Many thanks

yes it often happens but make sure you have "backup" experiments from a more established technique. Hopefully you will get good results from the new technique, but if not you can write up why you dont think it worked plus have some other results that might not be as new and exciting but at least you can be sure of...

basing a project around a technique can be risky. anyway, it's the question you are asking that should be more important than the technique being used. Are there other ways of asking the same question? maybe you could get a side project. good luck.