The standard wood picnic tables which you see at most parks and campgrounds have usually never seen the business end of a paintbrush. This is very sad because the simple process of painting a wood picnic table can make these tables last ten times longer without getting a single splinter into your softer side. One of the things I notice most often about painted wood furniture like picnic tables is that they are usually only painted on the top side and almost never done underneath. My thinking is that the entire piece needs to be sealed from the elements in order to make it last and keep it looking good all the time.
The process for painting something as large as a picnic table is a little different than what you would do with a smaller item. The trick is to get the paint layers to be uniformly thick and have the coverage be the same in all the little spaces between the wood pieces. It would be ideal to have the table in pieces before you start the painting project which is not usually going to be the case unless you purchased it unassembled. If it is held together with bolts then you can usually take it apart at least enough to make the pieces manageable. The most important thing I find is to make sure to cover all of the surfaces which will harbor water and debris as this is where the
wood will tend to rot first.
Plan where you will be doing the work as this picnic table will be there for at least the day and maybe even overnight. Try and avoid painting wood picnic tables in direct sunlight as this can make the surface too hot and your paint may end up staying tacky and it could even bubble up and flake off. Also make sure the humidity is not over about 70% as this extra moisture in the air will slow down the curing time on the paint allowing dirt and foreign particles to lodge in your paint. Always read the directions on your primer and paint looking for this kind of specification or requirement. Lastly prepare a plastic cover or tent to put above the table to keep pets rain and leaves off the table until it has thoroughly dried. Do not lay the plastic directly onto the table but prop it up on some boards or hang it from the rafters if you are painting your picnic table indoors.
Sanding and priming your wood picnic table are the two most important steps you will make when undertaking a painting project like wood picnic tables. The sanding makes things smooth but it also opens up the wood pores which helps them to accept the primer. Once you have uniformly sanded the entire surface blow off excess dust and wipe the surface off with a clean dry cloth. Next prepare your primer and starting on the underside of the table and the legs apply a thin even coat of primer to every surface that you can get your brush into. If there are tight spaces then get a smaller brush to make sure the primer is covering everything evenly.
After drying the primer coating thoroughly it is time to shake up your water based latex paint with UV blocking properties. Take your brush and put a thin even coat across the entire table starting on the underside first. The most important brush strokes you will make will be on the table top and benches as these need to be uniform and will look nicer if you take your time to make sure the brush strokes are even.
Now it is time to decide how many paint coats you will want to do. If the surface looks good and the paint is adhering well you can probably just do a thin second coat after the first coat dries. Allowing previous coats to dry thoroughly prevents the next layer from trapping the moisture in the paint which can make it bubble up or it will stay permanently soft and tacky. As paint dehydrates it loses the moisture that was built into it and it slowly cures the pores in the paint close up and this seals the paint to the layer of primer or wood beneath it. Point is you should not rush a paint job as you can have less than perfect results if you are in a hurry!
Now let it dry and prepare your shopping list for your first picnic on your new freshly painted picnic table. I always thought it would be fun to try using chalkboard paint on a picnic table to encourage people to be creative when they are using the table. Maybe this summer I will get to that project!