My back door is wood in the centre and has a metal capping on the outside. It has some dents in it in places. I have sanded the door down and prepped it removing all the old paint, cracks and previous paint job but I need to fill these dents to make it look better in black. What filler would you recommend I use? I have some Red Devil in the shed, would this suffice? I;d appreciate your advice. Thank you. Photos attached although the dents aren't very clear.