Tenino Copper Naphthenate 17% (2% as Metal) Double Strength - Highest Concentration Allowed - 1 Gallon - Wood Preservative

Works great but the smell is terrible. Hack for you to protect your treated wood. Use it at least 2 times on all cut wood (brush only) and if it is not revealed, coat with spectricide pruning spray to seal it and kills the smell, also protects. I did this on all my cut joist, post, and stair treads that is not seen. Also on all the knots that will weaken over time.

Great stuff! Wear your PPE though, stains whatever it touches. Easy application, dries quickly, good penetration, nothing bad to say.

Works as expected. The smell is very strong but it does go away.

Starting with my one dislike is the price, which despite its eye watering elevation appears to be the 2022 norm for the building supplies industry. That is the major downside to this paint. Having said that I’ll be quiet and go on with the review. This is an easy to apply thin green paint which contains 2% copper, which I believe may be the best (currently not banned in most of the US) residual insect killing fungus suppressing ingredient. Its essentially similar to the green color of treated wood since somebody governmental made manufacturers stop using arsenic as wood treatment. It tends to drip, but can be brushed, rolled or used to soak wood, and lasts a long time once it is dry. It smells of naptha, but its use is outdoors only. My intended use is for treating some 6x6 wood I need to make the foundation of a shed. (The reader is warned to not look at store prices of 6x6 treated lumber if they have any sort of condition which might make them prone to fits of outrage. If anything its worse than paint prices.)

Pressure - Treated, (Wolmanized, or whatever) involves stowing fresh lumber in a pressure cooker tank and letting it soak in vaporous and liquid material that will be absorbed. But it only gets absorbed on the shell, not in the innards. So, if your project involves drilling, cutting, sanding, scraping or otherwise removing material from the wood it needs to be re-treated as a prophylaxis against an early demise. Using this particular blend of chemical requires a full understanding of what's being touched and distributed, and a full understanding of how to use it and where to use it and what Personal Protective Equipment is recommended. This means downloading the full literature packet from the manufacturer's website and reading it before opening the jug. My project used 36 short boards and three long boards. There were 96 cuts and 216 drilled holes before assembly. I filled an old deep-dish cake pan about 1/3rd the way with the Naphthenate and brushed the cuts and used a 30mL plastic pipette to flood the drilled holes. A turkey baster would work, but it would waste chemical. A hypodermic syringe would work but they are traditionally a pain-in-tuchas to just get 10mL out of, to squirt down a hole. If I had to do any more, I would switch to a 1.5-inch diameter rubber ear syringe bulb because I could keep it filled and use the narrow tip to aim the drip into the drilled holes. Now my workshop area smells like Preservative as I let the chemicals seep into the wood before assembly, but I'd rather smell Copper Naphthenate than smell mushrooms as the wood rots. Once the stain goes on and once the topcoat of Spar Varnish goes on with the beach sand filler no one will smell any preservative. This product is truly the best for the serious fabricator.

No one can give an honest review of this unless they’re coming back 10 years after using it to mention if it works or not. I’ve used the Rustoleum version of this in the past so I was aware of the odor and thought people commenting on the odor were being over dramatic, after all, you’re buying it to protect wood, not freshen the air. I’ll say this, if the smell is any indication of how well it works it must work great. I’m surprised the post office delivered it… It was in a sealed plastic container, that was sealed in a ziplock bag, which was sealed in a cardboard box which was sealed in the Amazon shipping box and when I brought the package in and sat it on the table, before even opening the outermost box, the smell was filling the house and I had to sit the box outside. I used this to treat the entire top of a 10X20 deck we built for a hot tub, I went with this over the Rustoleum version because there’s was only .88 gallons (weird) this was a full gallon. There is also a higher percentage of the active ingredient in this, so you get more product and it’s stronger. It also smells a lot stronger than the Rustoleum so I’ll take that as it’s going to work better. I’ve seen people use the specialty deck sealers and stains and it just doesn’t last or hold up. None of those are code approved for treating structural wood that can then be buried underground so I figure this will work much better, I also wanted to keep the raw treated lumber look and this fit that bill, time will tell how well it works, so 10 years from now I’ll come back and update. The package says the smell and color will fade in time, hopefully the smell fades sooner than later because after treating the deck I can still smell it outside, strong, a quarter mile away walking up to my mailbox and the smell has permeated inside the house. Another plus, application was easy, I just poured it in a paint pan and brushed it on with a 9” brush, it soaks right in, no need to worry about brush strokes or marks. It also covers the area it claims, most things claim to cover so many feet and I end up getting about half what they claim. This says 100-300 sq feet and I got a generous 200 sq feet out of the gallon, with enough left over to 2nd coat heavy traffic areas. My only real complaints: There’s nothing on the label to indicate a before use cure time, it just says 1 hour before a 2nd coat if desired. There’s nothing on the label to indicate how long you have before rain. There’s nothing on the label to tell you optimal application temperatures. So I’m taking all that to mean none of it matters? There’s also nothing on the label to indicate if it gives UV protection or not.

Soaked in quickly with 2 gallons for 4 place snowmobile trailer. Worth it and smells better than old oil/ diesel mix.

I’m sure it will do the job it’s intended to. It came quickly and cap was taped down, gallon container was enclosed in a ziplock bag which was also taped and was also double boxed. There was no liquid leakage or any signs of such and container seems full, but outer box sealing tape was mostly broken and there was an odor of the product coming from both boxes. I believe this was only from vapor of this volatile stuff slowly making its way through the plastic bottle and the ziplock. I would suggest using a bag which is more impermeable to product vapor, padding between the two boxes which is more effective than the usual wisp of paper that’s normally used, and secure taping of outer box which will ensure its survival as a heavy item subject to rough handling. Came very quickly and otherwise survived its journey in good condition. Good price. Thanks!