SEAL-ONCE Marine Penetrating Wood Sealer and Waterproofer, Clear, 1 Gallon

Im in central FL and had this playhouse in the elements for maybe 1 week with heavy rain twice. After leaving it to dry it really dried out the cedar. Always kept it covered and only 6 months old. Glad I sealed it because it did not come sealed. This was easy to use and not messy. A little runny but worked well with a regular brush. Was able to get 2 coats on quickly since it dried fast. Dried very smooth, no problems with bubbling unless I was trying to get in the small spots and they would brush right off after a few minutes. Finish is smooth, hope this lasts. Great price and value compared to others.

First photo is the applied product . Second photo is applied on the right side, but I haven’t gotten to the left side yet. On the applied pickets, this morning, the day after applying , it’s still feels like raw wood to the touch. Which I’m happy about , it seems like the first round soaked into the wood, but did not give it a high gloss feel .I’m using it on my back fence. Clear, first off. It’s like any other can of paint, if you open it and go straight to application without stirring it well of course it’s going to be chunky. If you shake it, yeah it’s gonna foam up. You need to stir it very well, scrape the edges. I used an extra long kitchen whisk actually, I find it mixes so much easier but a paint stick is just fine. Do it thoroughly. I dry brushed really well then power washed it and let it dry for a few days. I used a corded paint sprayer on low output, stayed the same speed and distance away, did 2-3 boards at a time, and then went over them immediately with a paint brush to really spread it out. My wood was very raw and damaged from the sun and moisture so it absorbed VERY quickly which is why I sprayed just a few at a time and went over it quickly with a paint brush to push it in and around before it soaked up. It soaked in FAST. Some I had to spray over thickly a few times because they were so sun damaged and dry and soaked it up. But it took to the wood with careful application. I got about 25 feet of 6 foot standard picket fencing done with one gallon. We get the Marin layer in the mornings here so I did it in the afternoon when the fence was very dry and still had time to try again after applying it.

I am returning to leave this review having 3 years of experience with this product. I purchased Seal-Once Marine Penetrating Wood Sealer (clear) in June 2023, 3 years ago, and applied it to a large gazebo (from Costco) on my deck. Seal-Once has done a phenomenal job of protecting the wood, and the gazebo still looks almost new. My experience with prior brands of sealer/waterproofing caused me to do a lot of research while selecting which protection to use on my new gazebo. I live in sunny California so sun damage was my primary concern, but we average 54” of rain annually so I was also looking for water protection too. I have been pleasantly surprised that this product has really surpassed my expectations. I am a very satisfied customer and will continue to use Seal-Once Marine Penetrating Wood Sealer. (The attached photo was taken right after the gazebo was first installed.)

I had built this alter for our wedding back in 2013 and my wife and I wanted to seal it so we can enjoy it in our backyard. I researched this one thoroughly to ensure I chose a product that would protect our unique, custom super valuable alter. I chose Seal-Once Marine in the clear coat finish and precisely followed the instructions for the application. I allowed it to dry that evening and through the night with minimal contact with anything so that it cured properly. It goes on in a creamy white color, but then within minutes drys clear. I was very detailed especially with the many layers and colors of wood I was covering, and I made sure to let it dry a bit before coating each portion and piece of wood again. It dried out and we are so happy that our alter is thoroughly protected now against all elements. We have rain today for the first time since I finished the project a couple weeks ago and it is repelling the water very well. I feel so much better knowing that our memory is so well preserved! I’m leaving a four-star review only because the gallon arrived from Amazon pretty damaged, leaking and stuck to the box from shipping. Thankfully, we received a credit for it, and I was still able to use the majority of the product. Thanks Seal-Once!

Put one coat on some cedar fence last year. Noticed the other day how good it still looks. Went and coated it again and the product beaded up just like it was applied yesterday. Excellent outdoor sealer. This penetrates and makes water bead up but does not leave much of a surface film. Its super easy to apply and totally forgiving.

Had the worst possible experience with this. Follow the directions to a T. Applied the second coat as well, hoping to not have to cover the deck for 5-10 years.. It’s been months since the application. But after a rain, there’s this white milky substance on the top that comes out. If in the sun on a hot day, the product is extremely sticky as you’re walking, and if you have sandals on or sliding shoes, the shoes actually are like stuck in this goo. I did return the product. I did get my money back. But the company said spray the deck with water a couple times a day. It needs to cure. But if it’s a hot sunny day, and it has been at least two months, it just is a gooey sticky mess. So very disappointed. But at least the company gave us back our money, but I think the deck is ruined. And we did all this work to prep the deck and then coat the deck and it’s an absolute mess. Like I said, we got our money back. But on a cool day or not overly warm day, you might not stick to the deck. But on a hot day, it’s just like someone put glue all over the deck and you walk through it and just stick to it. We followed the instructions as directed and the second coat. Very sorry that we have nothing but a mess to deal with now and not even sure what to do. Since they gave us back our money, I’m not sure what else can be done. But will probably have to sand down the whole deck and apply some other product so that it’s water sealed. But I won’t be buying this again.

Awesome sealer! Actually clear as advertised unlike other sealers I’ve tried

Retired union painter here, cleaned my 440 sq-ft deck, applied a liberal coat with a roller and used 1 1/2-gal. of SEAL-ONCE clear. Very happy with results! Product arrived with clips locking the lid-did not leak as other shippers have (Walmart).

For a water based sealer this is really interesting. I bought two gallons and covered both sides of decking for a 14x10 deck. Hardly put a dent in the first can. Looks promising but time will tell

Built a new treated wood deck in the spring and waited until August to apply something to it. After researching and reading reviews about Seal Once marine coating I decided this was the product for my use. I couldn’t be more pleased with how easy it is to apply and it looks fantastic. Great product

great product. easy to apply and easy to clean up. used on 30 year old pressure treated wood deck and deck looks . stood up well over the winter. doesnt peel. just fades.

I was hesitant about ordering this based on other reviews. Product came well packaged. It mixed no problem. I am refinishing my dock. It has never been coated and is made of cedar. I stripped the gray with 50 grit belt sander. Then these photos before and after with 2nd coat applied. It was much easier to apply with an exterior stain pad then a brush and saved alot of time using that method. Keep a brush handy though to smooth out. Not sure why the colour tints are not available here but would have loved to get the cedar color. Updated September 14th 2026 Since originally posting this review a few months ago the entire coating has worn away. My wife and I spent a good deal of our own personal time to sand and coat our cedar dock to look new again. What a waste of my time. See the last photos for an update. I wouldn't even give this 1 star at this point.

Even though double boxed, one was damaged and leaked all over