Well I spoke to the kitchen company today about which primer they wanted me to use.
The chap I was talking too said in the past they have had problems with the oil primers not sticking to the MDF !! and that's why they recommend water based primers.
I told them I was going to use cover stain, and his reply was yes cover stain would be fine as its an American primer and the oil paints over there have a different make up as to ours over here !!
So unless someone on here can tell me why not to use it i will stick to what I know best and go ahead with cover stain.
One other quick question, do you tint / colour your primer for the second coat, to help coverage when applying the eggshell ?
Got to say I don't as i find the oil eggshell covers fine in two, ( I always give the outsides a 3rd coat ) so never thought of doing so but was reading the other day where a chap always colours his primer even on the first coat.