Lime to protect wooden fence posts

Hi all, I was wondering if anyone has any experience or info on using lime (I am thinking hydraulic lime for this) to protect fence posts from rot and termites? I was imagining soaking post bottoms in a 5 ga bucket of an activated hydraulic lime solution, like maybe a dilute solution. The extreme alkalinity it self may have an effect like burning the posts, as folks have done traditionally. Anyone tried this post in lime idea?

Thanks.

Did you ever get an answer about soaking fence post in lime water ? My dad has a very old book and it mentions soaking dry fence post in lime water then drying and painting with a weak solution of sulphuric acid. The author claimed fence post would never rot and wood was hard as stone. However author did not give any more details . Book was printed in 1930s .

Thomas, welcome to the forum!

I have heard of using lime as a whitewash to preserve wood though I have not heard of the application you are referring to.

I have read several threads about using borax in the application similar to what is being described.

You might try doing a search for "borax".

Pretty sure borax fireproofs wood, but maybe I made that up

Thomas Evans wrote:Did you ever get an answer about soaking fence post in lime water ? My dad has a very old book and it mentions soaking dry fence post in lime water then drying and painting with a weak solution of sulphuric acid. The author claimed fence post would never rot and wood was hard as stone. However author did not give any more details . Book was printed in 1930s .

I’m deeply curious. Could you tell us what the book is called? And even better, could you or your dad take a picture of the relevant pages and post it? That’d be awesome.

Thanks,
Daniel

I found this recently and think it could be of interest

HOW TO PRESERVE WOOD FROM DECAY WHEN USED FOR BUILDING AND NAVAL PURPOSES.
SIR,—The House of Commons and the whole kingdom are ringing with indignation at the discovery that nearly abl the gun-boats built during the Crimean war, at such an enormous expense to the country, are rotten, and that the bolts which fasten the outside planks and timbers together are several inches too short. In a letter in the Times,
May 14, 1860, signed, "Forewarned and Fore-armed," the writer asserts that the condition of some of our reserve steam fleet is not much better than that of the Crimean gun-boats.
Admiral Seymour (see
Times, May 16, 1860) stated in the House of Commons,
" that the original sin of these vessels (Crimean gun-boats) appeared tobe the character of the timber of which some of them were built. It was well-known that not only in her Majesty's dockyards, but in the private building yards of the country, there was a lack of that properly seasoned timber which the undertaking of a large number of such boats would require."
If such be the nature of a great part of the timber used in our naval dockyards, unseasoned, and consequently liable to rot and decay, the Wooden Walls of old England will, therefore, be unfit to defend her in the hour of danger. It behoves the Admiralty to try every means to have the shipbuilding timber more carefully looked after and better seasoned.
With this view, the following method of pre-
paring timber for building purposes, introduced by the late Sir Charles G. Stuart Menteith, Bart., of Closeburn, on his estates, is now given.
He was in the constant practice of soaking his timber, after it was sawn into planks, in a pond of water, strongly impregnated with lime. In consequence of this soaking, the saccharine matter in the wood, in which the worm is believed to live, is either altogether changed or completely destroyed. Scotch fir wood, employed in roofing houses, and other in door work, treated in this manner, has stood in such situations forty years, sound, and without the vestige of a worm. In a very few years, fir timber so employed, without such preparation, would be eaten through and through. Besides freeing the wood from all attacks of the worm, it is found that the lime water steep in a great measure prevents dry rot, and makes the wood sounder and more durable for years.

that is fascinating, John! Thank you for posting.

I’m pretty disappointed, though. When I got down to what the process was. I don’t know what any of those words mean!  Maybe someone can decipher that?

Thomas Evans wrote:Did you ever get an answer about soaking fence post in lime water ? My dad has a very old book and it mentions soaking dry fence post in lime water then drying and painting with a weak solution of sulphuric acid. The author claimed fence post would never rot and wood was hard as stone. However author did not give any more details . Book was printed in 1930s .

There's probably some useful chemistry going on here.

Google says that sulphuric acid plus calcium hydroxide yields calcium sulfate which, I think, should fully hydrolyze into insoluble gypsum inside the wood pores...

"The partially dehydrated mineral is called calcium sulfate hemihydrate or calcined gypsum ("plaster of Paris") (CaSO4·nH2O), where n is in the range 0.5 to 0.8.

In contrast to most minerals, which when rehydrated simply form liquid or semi-liquid pastes, or remain powdery, calcined gypsum has an unusual property: when mixed with water at normal (ambient) temperatures, it quickly reverts chemically to the preferred dihydrate form, while physically "setting" to form a rigid and relatively strong gypsum crystal lattice:

CaSO4· ½ H2O + ½ H2O >>> CaSO4·2H2O

This reaction is exothermic and is responsible for the ease with which gypsum can be cast into various shapes including sheets (for drywall), sticks (for blackboard chalk), and molds (to immobilize broken bones, or for metal casting). Mixed with polymers, it has been used as a bone repair cement. Small amounts of calcined gypsum are added to earth to create strong structures directly from cast earth, an alternative to adobe (which loses its strength when wet)."

Sounds like a worthy experiment, with relatively cheap, safe, and non-icky ingredients. I'm tempted to try it with the lumber in contact with the foundation of my upcoming garage/workshop building project.

Sorry for original text. Blame text copy by Apple iPhone from a screenshot image. I assumed all ok until I read it again in totality. I have made edit with checked and edited text. Hope this gets published before too many read it. Its all a wonderful learning experience I guess.
I am not sure if hydraulic lime is what is being used here.
I am not aware of any calcium salt which is soluble so it must have been a slurry of some sort. Cheers. J

For what its worth, about 12 years ago I built a cob extension with jutting out roof beams, wood was not treated apart from a few coats of limewash , they remain in perfect condition. My limewash was just ordinary builders lime (hydrated). We  use limewash and salt (to bind it ) for coloured interior walls.