Should I use a water-based latex paint or an oil-based paint?
This depends on the project you have at present. Both have its advantages and will do an excellent job under most circumstances.
Water-based paints is useful especially if it is a DIY project. It could easily be cleaned-up and easier to use. Top-quality latex paints also have excellent adhesion and resistant to bleaching and fading when compared to oil-based paints. Contact also your independent paint retailer to for a professional advice.
Is it necessary to apply 2 coats of an exterior paint for finishing?
This depends on whether this is a new siding to be painted or an olp painted wall where there are still remnants of the prev paint. For the former, a primer should be applied then two coats of paint. For the latter condition where you are just going to reapply the same color of paint, a single coat may be sufficient already
How long does it take for a paint to “cure”.
This varies depending on the color choice and type of paint. Latex paint may take up to 60 days for a “full cure”. In most cases, latex paint can be put to normal use after a day or two. Fresh latex should be allowed to cure for at least 14 days before attempting to wipe or wash the walls. It can be sensitive to water or chemicals during the curing process.
How to prevent lap marks in the dried paint?
Lap marks appear when a wet edge is not maintained while painting. It can also be caused when the paint is applied in a vertical motion only.
Make sure to keep a wet edge as well as spread the paint in a “W” or “M” pattern on the wall. This will help spread the coating and create an even film on the surface. Once this is done, you can go right back over that area and roll from top to bottom to minimize a “shadowing” effect in the dried film.