Spraying Tree Trunks with water

[niemeyjt]

I was driving past a wood mill with loads of large trunks stacked outside awaiting processing.

I noticed some were being sprayed with water. No idea about species.

What's going on? Surely the aim would be to air dry the trunks - not moisten them?

Anyone with any ideas?

 

[Phil Pascoe]

Stops them drying quite so quickly.

 

[Terry - Somerset]

With the recent hot weather would there be a real risk of splits developing as the outside dried too fast. A good soaking would be cheap and quick to apply.

 

[MARK.B.]

Could well be something to do with the temperature and stopping them getting to dry before they are processed, have seen videos of mills in other warmer countries where they have permanent systems that spray the logs with a fine mist of water to prevent drying out.

 

[Sgian Dubh]

It's quite a common practice, as well as actually sinking sawlogs into water ponds and even rivers and natural lakes. Primarily it's used when there's a significant gap between felling and boarding up and seasoning, especially in hot countries or areas where processing (conversion and seasoning, etc) can't keep up with tree felling. The purpose is to reduce the number of faults such as end shakes, longitudinal splits and so on. There's a lot of potential stress in a large round sawlog as those parts exposed nearest to drying forces shrink, i.e., the ends and the outside circumference, whereas material closer to the centre remains wetter and full size. Slainte.

 

[Orraloon]

Spraying treetrunks. My dog is pretty good at it.

 

[topchippyles]

A lot do it to remove all the dirt prior to milling saves the blades getting blunt. I mill using a bandsaw mill and jet wash dirty logs covered in soil. Hot weather as well as others mentioned stops drying to quick.

 

[heimlaga]

Thre are three very valid reasons:

1. Logs that are wet enough aren't as rapidly attacked by fungi and insects as logs that dry slowly. There is a critical stage in drying and an unbarked logs spends lots of time in that stage before it is dry enough to nt rot nor be eaten by insects. For this reasons logs were often stored in rivers and ponds for years in the old days. Spraying can postpone the damage by a couple of months givng the sawmill time to catch up.
2. A log that is drying in it's natural round state is boundto develop plenty of radial cracks which you don't want in the boards you saw out of it.
3. Dry timber is much harder to saw. You must feed slowly and the sawblade has to be resharpened often.

 

[Inspector]

All the reasons above and here where the sawdust piles can be massive they have sprinklers to keep the entire pile wet and cool to avoid spontaneous combustion and the resulting mill fire.

Pete

 

[clogs]

I found a wooden barrel factory in SW France...
never seen so many felled oaks...they were spraying water 24/7...
Hate to think of the value of those logs and that was 10 yeras ago....

 

[MikeJhn]

French Oak is not expensive, the Oak woods are grown to be cut down mostly for fire wood, the rural parts of domestic France are mostly heated by log burners or even open fires.

 

[stuart little]

I've seen it all over Scandinavia & Germany. Remember 'Axe Men' on TV, recovering cypress that had sunk decades ago while being floated down river - worth a fortune I believe when milled, &

 

[Phil Pascoe]

It's quite a common practice, as well as actually sinking sawlogs into water ponds and even rivers and natural lakes ...

I remember a visit to Tregothnan (Lord Falmouth's estate) and seeing 50' - 60' boles of douglas fir lashed together floating in the river. They were kept there to season then floated down river to the Falmouth shipyards for masts.

 

[stuart little]

I remember a visit to Tregothnan (Lord Falmouth's estate) and seeing 50' - 60' boles of douglas fir lashed together floating in the river. They were kept there to season then floated down river to the Falmouth shipyards for masts.

Yeah, that's in the old tradition of ship building.

 

[Forester63]

As others have alluded to above it helps to control defects developing in the logs. My understanding is that the principal reason is to control the risk of blue stain developing.

Pine is particularly susceptible to this defect caused by fungal growth within the sap wood (sap stain being an alternative description). Fungal spores are carried into the wood by bark beetles. Irrigation restricts the supply of oxygen which helps to restrict fungal growth and maintains a high enough moisture content in the wood that reduces beetle activity. Whilst there is a negligible effect on timber strength the blue stain devalues the timber because of its visual appearance.

Mills are normally pretty good at managing log supply so that it doesn't sit around for too long. Where that falls down is after a large storm event when 000's of tons are brought down in an unplanned way. Up here in the North East we still have loads to deal with after storm Arwen although there is a lot more spruce which is less affected. The last large scale storage of logs under irrigation that I remember seeing was in East Anglia by the Forestry Commission where pine is the predominant commercial species. This was after the 1987 storm.

 

[hodsdonr]

Logs at a Veneer mill are kept wet to keep the veneers cut off flexible. Logs are stacked outside under constant sprays

https://www.berkshireveneer.com/berkshire_veneer_video.php