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

Arrived promptly and was well packaged to prevent spillage. I wore a respirator, nitrile gloves, long sleeves, and glasses for protection. I applied two coats with a four inch brush and used half a cup to cover a 16 square foot plank, which will contact the ground. Goes on easily, absorbs well. Colors the wood green, so easy to see where you have applied. Strong odor that diminishes daily. Hoping planks last a decade.

Great product. My husband used this on treated lumber to redo our deck. Many years ago, it was called pinta, I believe. It gives an extra layer of protection on your wood. It is easy to apply and works!

This stuff soaks in good. I char untreated wood with a flamethrower then put this stuff on. The people saying it stinks makes me laugh. I’m a mechanic. This stuff smells like the inside a band-aid tin from the 90’s. Thats it. Just a really strong band aid odor.

Like other reviewers have said: 1) The jug leaked in shipping. See photos. Ordered 2. 1 leaked but Amazon refunded my money immediately since it’s not returnable. 2) It’s quite smelly but not unusably so. 3) Product is easy to use but, at least on old wood, a gallon doesn’t go very far. My 10 year old deck just sucked it up as fast as I could brush it on. 2 gallons only covered 135 sqft. That’s less than even the low end of the quoted coverage range of 100-300 sqft/ gallon. 4) Although it’s not supposed to be a sealer, the second coat coverage was at least 3 times that of the first coat. Overall, I’d buy it again.

If you are using it on trailer boards, it works great . Will not leach out like a lot of wood preserves do.

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.

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.

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.