For 28 years we've used oil based paint on our garage doors & house shutters. We'd like to change & use a good latex paint. We understand from your shows everything has to be sanded to provide a 'rough or porous' surface for the new latex paint. A friend mentioned there is a product out called 'liquid sander' that you apply. The shutters are wood & the 2 garage doors are a wood/product, and small doors are metal. One of these doors we noticed is starting to peel. How do we treat this metal door - the same as the other items? How do we remove the old paint - does it have to be all removed?
Answer:
Don't forget that if you paint one side of a large wooden (or compressed wood fibre) sheet, you create an unbalanced sheet for moisture content and that can make it warp. Both sides must be primed and painted. As far as the metal door goes, if some paint has already started to blister and peel, count on it, the rest isn't going to be far behind. Take a heat gun to the metal door and strip it of paint. Now you are ready to prime and paint. As far as the liquid sander goes, I've heard of it but never tried it - the paper and steel wool system I've been using for some decades works very well and that means I won't change on a whim. I'd still use the primer suggested to you by the chap at the paint store but I want it applied to a very a clean (down to virgin metal or wood) surface.