All painting projects, interior or exterior, require prep and attention to detail. Taking shortcuts will lead to a low quality paint job that won't last very long. Here's what you should not do on your next painting project.
Trying to Cover in One Coat
It's a bad idea to put on a thick layer of paint to try to save time. One coat rarely covers well, and a thick coat of paint will run and take forever to dry. Applying two thin, even coats is easier and will give you much better results.
Not Powerwashing Siding Before Painting
No matter how many layers of paint you remove, sand, patch and caulk and use the best primer and paint. The paint will fail if you skip power washing your siding first.
Not Sanding Walls
For a lump-free finish, sand your walls before you roll on paint. Sanding gets rid of bumps, roller lint and other crud left from previous paint jobs. It's best to use a drywall sanding pole and 80- or 100-grit drywall sanding paper. But you can use a handheld sanding block. It'll just take longer.
Painting Over Un-primed Patches
If you have a drywall patch and paint it without priming you will have what is called flashing. There are two ways to prevent flashing. The first is to prime over the patch with a sealing-type primer. The other is to use self-priming patching compound, such as 3M's Patch Plus.
Painting 2nd Coat before 1st Coat is Dried
Don't be in a hurry to get the job done. If you paint over partially dried paint you are likely to loosen the first coat of paint and create a mess. Even if this doesn't happen, painting over paint that's not dry can cause adhesion problems or slow drying time. Always follow the drying time instructions on the paint can.
Skipping Masking the Baseboard
I myself can cut in a straight line without masking off baseboard and trim and yet I still mask off the baseboards. Masking prevent paint spatters. You don't have to completely cover the baseboard. A strip of 2-in tape will do.
Skipping the Prep Work
There's no doubt that washing, patching, caulking and sanding are tedious and time consuming tasks. But there's no substitute for good prep work if you want a great-looking paint job.
Not Caulking Gaps
If you expect the paint to fill the gaps against your baseboards you would be wrong. When the paint dries, the gaps will reappear and you will have to caulk anyway. Caulk first, then paint.
Not Mixing the Paint
If you find yourself needing to do a bit of touch up paint and reach for a can that has been sitting in your basement for awhile, first thoroughly stir the paint or you may be surprised to have a different shade of color on your wall once the paint dries.
Not Sealing Wallpaper Before Painting
Always use an oil based stain-blocking primer on wallpaper before painting it. If you skip this step the wallpaper will soak up the paint and start to peel of, turning a one day job into a week long project.