Home DIY

...with very long lasting outdoor paint....needs at least 16 hours to dry...

I'm assuming I need to strip the whole door right back and sand it?

Can I knock out the damage to the pelmet and then fill it with polyfila before painting over, or does it need to be done properly?

Any advice as to what will remove the tough paint from the concrete, without damaging the path?

Sounds like a spirit based paint, in which case white spirit, a rag, time and patience should bring most of the paint off the path. Similarly, many of the smears on the door glass could be wiped back, but the longer you leave it the harder this will be. Cheap nail varnish remover might also work, but only on the path: moisturisers in pound shop stuff will contaminate the door paint and cause problems with the next coat. Just watch out for solvents removing the bitumen binder in the path as well as the unwanted paint.

If you're lucky, the wrinkled paint surface will be a consequence of too much paint applied too quickly. If this is the case you could probably leave it a week (or longer) to harden then sand to a smooth surface (irrespective of colour) before repainting with the same type of paint- repainted by someone who can read and understand what it says on the tin. If you're not lucky it might be a reaction between different types of paint (e.g. spirit based applied over acrylic) in which case stripping right back is probably the best option.

The pelmet can be retrieved by knocking out the cracked parts as you suggested - just don't use a 'gap filling' / flexible polyfilla, often in a squeezy tube - it is overpaintable but doesn't sand well. I'd use something more like http://www.polycell.co.uk/product/polycell-plaster-repair-polyfilla-powder/ or one of the equivalent Tetrion products that can be applied in several layers and then sanded smooth before repainting.

Looks like an Easter project, requiring more time than money, and weather permitting...