Asked on Jun 05, 2017

Can I put polyurethane over water sealed wood?

Bill Kratz
by Bill Kratz
I building a plant bench to be used outside. I sanded all the wood, applied Thompson's waterseal with stain. Once finished can I apply Minwax polyurethane before putting it on the front patio which is only partially covered?
  6 answers
  • William William on Jun 06, 2017

    Thompson's Waterseal with stain is a protective finish for exterior wood. It contains special UV shielding pigments and mildewcides to ward off mold, mildew, moisture, and keep the wood from fading. Other sealers or clear finishes will not adhere well to a Thompsons stain and may result in the topcoat failing prematurely. Most likely the clear sealer or polyurethane will end up peeling and flaking off the stain.

  • Susan Rhoades Susan Rhoades on Jun 06, 2017

    I've used a marine spar varnish on stained wood on my stained wood porch posts and railing and it held up very well but that varnish was NOT applied over Thompsons, a product which should provide all the moisture protection you need. You need to reapply the Thompsons every year, but that's not a big deal. Do nothing and see what happens.

  • Bill Kratz Bill Kratz on Jun 06, 2017

    Thank you for your response...It'll also save me a little needless time.

  • Christine Stjohn Christine Stjohn on May 03, 2018

    I painted a rocking chair with interior paint ,how can I make shiny and water proof.

  • Johnavallance82 Johnavallance82 on Nov 11, 2022


  • Mogie Mogie on Nov 11, 2022

    Shiny just look for a sealer that has a high gloss finish.