Garage door - flaky paint

[MetalGnu]

Hello,

We have a metal garage up and over door. Red paint, with a think, drippy coat of black on top. It’s quite large 4.5 m by 2 m. The paint is very flaky in places, revealing large areas of bare metal, but well stuck in other places.

would it be advisable to remove all the old paint before priming or can I prime over the exciting paint?

Thanks.

David

 

[Wayners]

Need to get the paint off without damaging galvanised surface.
Heat guns can damaged galvanised metal while modern paint stripper is not as good as it used to be.
Try and get what you can off, prime the galvanised bits.
Apply flexible exterior paint.

Warning as scrapping can also dig through galvanised surface

 

[DiyNutJob]

Get all the loose paint off, then spot prime the low/bare areas. After dry, sand the higher old paint areas on the perimeter of the primed spots. Then prime again to raise the low spots. Then top coat and sand the perimeter to lower the high areas. Repeat this until satisfied. You can get as good a finish as you have the time for.

If you don't have the time and patience then priming and painting is fine. At a distance, the imperfection might be acceptable, especially when you don't deliberately look for them. If there are rusts, I would suggest using rust converters before priming.

Stuck on old paint should not be seen as a negative. The better they are stuck on, the greater the protection they give. Protection means money saved. Good looks only saves the ego.