So, it turns out the question I should’ve asked is “Should I REALLY be allowed anywhere near a plastering trowel?”
to which the answer is a most definite NO!!!
I should’ve learnt from when I first tried plastering that I am rubbish with a trowel. I just made a mess.
ended up giving up, scraping it all off and went back to metal frame instead.
if I ever ask a question about DIY anything that involves a plastering trowel please tell me to not be so f*****g stupid and to pay a professional.