Thanks George
Yes, we know about the 80% rule. That's what he has been putting in.
Maybe I've just been unlucky with my compressor(s)?
I'll know shortly cause I pulled a compressor off an old Holden I have lying dead down the back. It showed no signs of oil leaking and it was still holding gas after 16 years since last recharge. If this one holds I'll be OK. Fingers crossed
Experience is that marvellous thing that makes you recognise a mistake when you make it again.