The Volvo's nearly drove me over the edge when, a couple of weeks ago, despite a second new head gasket and a head skim started blowing coolant out the exhaust for a 3rd time. With almost all possible remedies exhausted it was time for some more diagnostic work.
One die pen crack detection kit later and here's what I found....
A nice crack straight accross between no.2 back exhaust and inlet, stretching quite a long way into both ports for good measure.
So, that head is scrap then....... It t'was time to think again.