Ok after spending the Christmas break gluing, pulling apart, cleaning and re gluing . have now found method that is working better after a bit more research. Basically i have taped either side of the gluing area and scuffed up the Armour slightly and the underside of the cover strip to give a keying surface for the glue, although still possible to pull apart but slightly better foundation.
once i had the glue applied i suppose i might have used a excessive amount of magnets!! but it was going to work this time.
but i am happy to report that indeed it has worked this time and i have a finished set of Biceps