Hi, my front door is about 8 years old made up from some sort of hardwood I guess. The previous owner had the door decorated with an coulorant/stainer which gradually deteriouted. I sanded the door down and primed it/two undercoat and topcoat with Dulux gloss. Problem is minute cracks in the wood keep showing through! They seem to small to use filler, I am now thinking of burning off the paint and starting over, but what, if any, sort of wood filler could I use? The whole door is affected by this cracking. Thanks for any help you can offer.