I wonder what species of oak you use to get 25 years out of a bed - or - does it get housed out of the weather? I built a 20ft flat bed trailer in the winter of 1980/81. It uses 20 rough sawn 2x12x8ft boards as a deck. The first oak bed was treated with a military surplus wood preservative. It was a clear product that had a peculiar smell. I know nothing more about it. That bed was replaced about 14 years later in 1995. The replacement bed had boards that needed replacing in a handful of years. I replaced the bad boards. It had total replacement about 2003. The bed needed replacing 7 years ago. At this point it is nearly unusable. I have about a dozen 18"x32" steel plates lying loose on it covering holes and bridging weak areas. The trailer needs 6 new tires and a bed. With local lumber prices at about $650 for 20 planks plus an additional 35ft of 2x4’s and needing (6) 8x14.5 tires - I’m seriously wondering if I will be able to continue to have the trailer.
Red oak is the best around here. I have seen it last outside in the weather for about 25 years. White oak has only held up for about 15 years but both where literally put outside with nothing done to protect them.
I think black oak also holds up well but I haven’t personally used it. It is kind of rare around here.
I would guess locus would hold up very well too but it would stink. I have seen locus posts hold up very well.
The point in time arrives when you have to ask yourself: Do I still need this thing at all? Could I rent one for the few days a year that I actually need it’s capabilities? Could I replace it with a more efficient or smaller unit? Do I just love it and/ or it has sentimental value? (example: my Dad’s old leather aviator jacket or the John Deere mower he bought new). I love my Subaru Forester (2007). It has 292,000 miles on it. It needs more work than it is worth. I have decided to drive it as is until it wont go anymore. It is my commuter vehicle, and gets decent fuel mileage. I depend on it daily. It has only broke down a couple of times, arguably my fault. Bad struts all around, bad A/C compressor, Check engine light on for 2 years (I know a fuel venting pressure problem=rust). I would have to fix all this myself, I am not that capable anymore. I will drive it until unreliable.
Ron,
Maybe some new planks will find their way to you at low cost or free for the hauling. Prayer works! Ask Bob M.!!! (and his new Bees) 
we use white oak, red oak, and post oak. the only thing i do to protect the wood is dump burnt motor oil on it every once in a while. We also did that with pine we had it last for about 7 years.
Well this trailer is the only one that can move my forklift, tractor and now that m
y 16ft trailer is broken - I use it to haul slab wood bundles for heating fuel. I sure don’t use it weekly like when I had the business. Just maybe 4 or 5 times a year now. Donations??? I wouldn’t ask someone to donate that much but possibly a deal could be struck. Sad that so much iron at the shop is getting scrapped. Someone could probably use some of it. I do have a 6K capacity single axle hydraulic tilt trailer that could arrive at Argos to haul some planks home…
Locust will last a life time, if you have it. Next, White oak( must be dry) will last the longest, and if you want it to last as long as you do, take a weed burning propane torch, and blacken it, all sides. I have seen blackened locust posts over a hundred years old still holding fence wire.
Interesting I never heard of blackening the locus but untreated they will last about 40 years in a cow barn at the back of the stalls and that is a constant nasty manure mess. There where orginal locus posts when we took down the stall barn here.
Hi all , Ron just reading about the life of your boards and wondering are they rotting out ? or just breaking up due to years of hard work ?
Has anyone looked into burning there wood ? Charing it so the surface is burnt they say that tree’s left from the bush fires here will not break down where they are charred on the outside they will just sit and sit and even repel water to a degree .
Plenty of articles on this online .
Dave
The Charing of wood can make it nearly impenetrable by moisture, I think it was the Chinese that perfected it and purposes it into roofing materials for there temples…sugibarreigh? I’ll be damn if I remember how it is spelled, but the technique was used by a YouTuber I watch, Shawn James of my self reliance. He blackened wood planks to roof his off grid cabin, 3-4 years and going strong. Was very neat to see, he also blackens all his fence post for the same purpose
News to me about blackening wood. I wouldn’t have been able to blacken the top side for what we used it for. My trailer really hasn’t been used much in the past 20 years. We built it to haul concrete block behind the boom truck but the business died with the economy tanking. A cube of block is 3000 lbs spread out over 40"x48" so 13.33 sq/ft or 225 lbs per sq/ft. A guy standing with his feet close together is about the same weight. The boards simply get soft, crack and fall apart. The top side is of course worse than the underside in appearance. There are 5 weight bearing points down the length of the deck. There is a center longitudinal 8" channel iron with a wood spacer on top. Then 2 frame rails of 8" I beams with wood on top that the axle springs attach to. Then the side rails are 2"x2" angle iron with 1.75x2.75 tube supports every 18inches or so. The side rails are turned up to cradle the ends of the boards and protect the board ends from the forklift banging into them during loading. I built it so that the only steel that could rust and stain the concrete block are the 4 3/8" carriage bolts that affix each board to the frame.
Guys in my area with wooden flat beds paint the wood with used motor oil. Not sure how good it is at actually keeping the wood strong so maybe they’re just using it as a cosmetic stain.
Used Motor oil is good and cheap. And lasts.
Only splash/brush/mop it on in the hot and dry though so it can be absorbed in.
Slicker than snot if applied in the wet raining. Make that mistake then sprinkle with sand.
S.U.
They simply rot-crack. Of course the upturned surface softens and the softwood weathers leaving deeper cracks for moisture to accumulate and lead to accelerated deterioration.
Somewhere around 1890 when they were logging off this area somehow they ran a railroad through the swamp at the back of what is now my property. They pulled the rails up around 1950 but the ties are still in the railroad bed and many are still holding rail spikes that you cannot pull out. Don’t know what they treated that wood with back then but I think it was coal tar. I can show you pictures of fence posts that are still standing that I know have been in the ground for at least seventy years. Not much left but still standing. Those were cedar soaked in barrels of coal tar.
I know around here they used to soak anything going into the ground with creosote, I have fence post that were pulled from a family friends farm that were in the ground over 50 years and in perfect condition. I don’t know what happened to it but we had the barrel of creosote he used to soak them in too, when it started getting low he filled it with used diesel engine oil and that seemed to work good as well
For the poles (just trees) of a sawmill building, that was built a long time ago, we removed the bark, where it was in contact with the soil. Then applied used motor oil. After the poles were in the ground, holes were drilled around the poles, above ground level. Every so often the holes would be filled with used oil. Not sure how long it would last. After about 30 years the roof caved in because of a heavy snow load. The type of wood and the soil is a large factor.
Edit: The holes were capped with bolts, to keep saw dust and dirt out. But, there is no reason why the holes could not be cleaned out with a drill bit.
I volunteered for our local rails to trails group 20 years ago. We had acquired a number of miles of rail grade where the track and ties had been removed for reuse back in the mid 80’s. The grades were overgrown and I took on the task to open them up with my tractor and brush hog. While clearing the grade I could look down into the swamp area’s and still see the vestiges of telegraph poles sticking up out of the mucky water. The centers gone - just a hollow wooden ring sticking up a few inches to a foot above the swamp surface. Given that this section of rail line was being placed in the 1860’s it is quite likely that the telegraph poles were placed in the same time frame.
I don’t know if they remained due to a preservative nature of the muck or if it was the creosote that the poles were soaked in.
Of possible note - My 1916 Mechanical Engineers Handbook describes creosote as a by product of coal tar in the manufacture of illuminating gas or coke. Not from wood. Railroad ties soaked in the product absorb on average 23lbs of creosote. The required specifications for amount of creosote for various regions in the USA are given here in this manual. They range from a low of 10lbs minimum to 25lbs maximum.
There are 7 creosote impregnating processes described with some including zinc chloride as either being present in the creosote solution or as part of a treatment process. Allardyce Process, Card Process, and open tank all use zinc chloride as part of the creosote treatment process.
When creosote could not be used due to the staining and smell either a zinc chloride treatment/Burnettizing process was used or Kyanizing/Mercuric-chloride was used alone
I am rather surprised that none of the processes at the time used copper or are at least not mentioned.
Zinc-chloride alone
remains water soluble and washes off when exposed to weather.
They state that the average life span of red oak or pine cross ties treated with zinc chloride to have an average lifespan of 6-11 years. Pine treated with creosote last 15 - 20 years or more. Wood piling when treated with a creosote oil of high specific gravity will last 15 years or more. They mention the Forrest Service Bulletin # 78 for a brief account of wood preservation.
Charring posts is a great way to preserve them…lots of early American livestock was fenced in with charred poles for fence posts…pre-pressure treated, pre-oil, pre-arsenic, pre-creosote. As we all know, charcoal doesn’t rot.
It’s really messy to make, install or work with. Sometimes horses and cows like to gnaw on it. But get a good hot big fire going with lots of coal bed…drag green poles through letting them get good and burnt/charred, keep dragging through until done…cut to length and reinsert the ends of the post to char the ends. throw it in a pond or tank of water to quickly quench.
start with “logs”, end up with “poles” = use bigger trees than you imagine you need. Lasts for many many years.
I had know about this for many years as my grandpa told me stories of charring fencepost on his homestead growing up, but for those that want to see it in action check out
He uses this technique exstensivly in his newest cabin build with underground root cellar