Pressure treated wood over time will dry out and crack. Regular treated wood will rot or crack out over time and non treated wood just rots all togather. All this because of water and air getting into the wood pores and grains. If you want something you have made of wood to last longer this treatment will seal the wood so air and water stay off and out of it. First make sure the wood is not wet and sand the wood down smooth then wipe it clean with a clean dry cloth rag. Mix some fiberglass resin up and add a little paint thinner to it just enough so it isn't thick. Take some cheap paint brushes and slowly and at a even rate brush the resin into the dry sanded lumber. The wood will soak the resin in. Keep applying until the resin will not soak in anymore then let sit overnight or until you don't feel anything tacky. Fiberglass resin is more waterproof than primer, paint and stain and will not blister or fade like the other products. Once the resin is dry you can sand the now resin treated wood to prime and paint if you so choose but always use a good sandable primer such as rustoleum sandable automotive primer. This technique will make your lumber last longer and if painted will your wood projects look like a high dollar job.