glossing over dark colours

[lancenotalot]

Have been doing a job this week with 10 doors and frames,not too much of a problem when repainting a light colour.These doors however were a dark mustard sort of colour and also a bannister and stair rail in a dark mahogany,lightly sanded to provide a key and then undercoated twice,put on top coat but still a little patchy in areas.Is there any undercoat that has a high opacity?I used dulux trade undercoat.

 

[Zampa]

Dulux new work undercoat might be a bit better..

 

[acaena]

Iuse Dulux Trade oil based undercoat with 2 topcoats dulux trade satinwood this 3 part system covers any dark colours the water based system might not