Understanding Penetrating Stain VS Film Forming Finish

There are two types of exterior wood finish being discussed here:

1.) Penetrating Stains
2.) Film Forming Finish (Mountain XT Clear 00).

Penetrating deck stain is going to  absorb completely into the wood; like a coffee stain. A film forming finish is going to lay on the surface; like a piece of paper. Penetrating stains are easy to maintain but are more exposed to the elements which means they wear away faster. A film forming finish of Mountain XT Clear 00 lasts dramatically longer but if it is neglected maintenance is more difficult than a penetrating stain.

Some wood needs a chance to weather for a year [acclimate] before a top coat film can be applied, for these wood types a penetrating stain is best while the wood acclimates. Other wood types readily accept a topcoat, even when new. Use the Ask Earthpaint tool for help to discern this and for customized recommendations regarding your wood type and region. You can also use the 1 year test below to see how the finishes hold up on a specific wood in a specific region.

1 Year Test
A method to see how penetrating stain works compared to Mountain XT Clear 00 on your wood type.

1.) Wash with Lime Clean, dry and sand with 50 grit.
2.) Apply a single penetrating coat of Rainforest Sealer Deck Stain.
3.) In a small test area, Apply 2 coats of Mountain XT Clear 00. Top Coat a few horizontal deck boards for observation. Choose high weather exposure boards and top coat fully with Mountain XT Clear 00. Do two coats if the first coat doesn’t fully cover the wood fibers.
4.) Observe these test boards over the course of a year. If they still look perfect in a year, you know what the best deck stain is. Then the next time the wood needs coating you’ll confidently apply Rainforest and Mountain XT Clear 00.