The Benefits of Watered Wood: Why It Was Once Popular and Is Now Rare
In the past, most types of wood were often “watered”, meaning that the fresh logs were placed in clean, fresh and, if possible, running water for a longer period of time after felling. The logs are placed with the “butt” in the direction of the flow, i.e. in the same direction that the sap flows move, to promote flushing.
The watering duration can vary between 3 months and 3 years depending on the type of wood.
This has several advantages:
1) Insects cannot reach the wood under water. (with the exception of the shipworm)
It is important that the log is largely submerged, otherwise it will still be in an oxygen-rich environment.
Woods with a specific weight that is too low to sink must be helped with additional weight.
2) Sap compounds (sap flow) are “flushed out”, so that insects, woodworms and fungi are no longer interested even after the wood has been removed from the water, due to a lack of nutrients.
3) The wood becomes “milder” and therefore easier to work with
4) The tension is released from the wood, which leads to fewer problems when sawing.
5) The color becomes deeper and the drawing more expressive.
6) The sapwood changes color with the heartwood, which significantly increases the yield. This is especially true for elm and walnut
7) The “work” of the wood is significantly reduced (shrinkage and swelling) because the hygroscopicity is reduced, i.e. the absorption and release of moisture into the air.
8) Head cracks, wind cracks and surface cracks are significantly reduced.
9) The wood becomes more durable for outdoor applications. Think of the Northern European pine window frames of monumental buildings, which are often still in perfect condition even after 100 years. This is impossible with the unwatered pine available on the market today.
10) After watering, the drying process in air occurs much faster because water evaporates faster than sap.
11) The trunks are easier to debark.
12) In elm trees it prevents the spread of “elm disease”
13) When painting softwood, the paint adheres much better.
Why is hardly any wood watered anymore?
There are several reasons for this:
Most importantly is the cost aspect - after the wood is purchased (and paid for) at auction, most companies can no longer afford to have the wood tied up for another two years before it is processed. In addition to the interest costs, there are other expenses for “handling”, such as double transport, double crane costs, tying down, sinking, etc., not all of which can be included in the sales price. In most cases, the market is not willing to pay this additional price. This is only necessary for specific projects and exclusive restoration work. It is also still used in specialised shipwrights' yards, for instance for ship's masts.
However, there is a type of wood where watering can be worthwhile. Walnut. Until it is fully grown, a walnut tree hardly has the much sought-after dark heartwood. Only old trees slowly but surely develop a darker core. The majority is made of sapwood and transitional wood, which has a very light color. However, due to the water, these colors converge. To intensify this effect, it is often steamed afterwards, so that the usable, i.e. “saleable” walnut wood content increases by up to 50%.
In my experience, elms should always be watered. Not only because the colours become much more intense and the sapwood changes colour, but above all because elm is very sensitive to woodworm. Elm sapwood is rarely spared from insect damage. In Dutch, the word for woodworm is often associated with “olm”, an old alternative name for the elm tree (also called “olmen”, related to the Latin Ulmus). The exception is elm used for parts in regular use, such as hammer handles or coach and vehicle bodywork — there the worm doesn't take hold, because it doesn't like vibration. In the past, people used to joke about finding woodworm in an elm bed: apparently, that meant very little had been happening in it.
The second problem is that due to regulations there are hardly any places where irrigation is allowed. You can no longer place logs in every ditch, canal or river. Not because the process is harmful to the environment, but because of the shipping routes, water flow, and drainage options and the strict regulations associated with them today. Sometimes we took logs to Houthandel Noordman in Leiden, where we could soak the logs in the Galgewater next to the famous sawmill.
A third problem is that water today is often contaminated with all kinds of metals. This is particularly a problem with woods that contain a lot of tannic acid, such as oak and chestnut. The reaction causes the wood to slowly turn blue.
It is hoped that the true wood lover who appreciates only the best quality will one day return to this practice.
Wood is still watered abroad, but due to time constraints, the ideal time periods required for the entire process are no longer available. Think of the transport of logs in Scandinavia, the USA and Canada, floating in large rafts across the great lakes and rivers. The teak trunks in Myanmar that are floated down the rivers to Thailand.
In recent years, a trade in watered tropical wood species has also emerged from Suriname. Using mostly Brazilian divers, the trees are harvested from the flooded jungle, now called the Brokopondo Reservoir. The trees there have been under water since 1965.
If you have any questions or comments, you can contact me at any time.
Maarten van de Voort – Timber Merchant in Tilburg
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