Thread: Drying time - fallen trees?

Originally Posted by RSD

I know that the rule of thumb for slabs is one year per inch of thickness, but what is the rule of thumb for trees that have been down for a while?

It's highly variable and non linear depending on
Type of tree
How they were stored/Climactic conditions
How longs its been cut down
Size of tree

I milled some 25mm boards from a small (18") swamp mahogany near perth that had been cut down for 24 months and they were dry in less than 3 months.

OTOH this jarrah (it's a branch) was cut down in the 1930's lay in dense bush (with average rainfall 1000mm/year) until I milled it in 2010, two inch slabs still took two summers to dry out.
A 3" slab from the same branch I milled at the same time was just as dry as the 2"
When I cut the end off to trim the length several buckets of water poured out of the centre of the log
JoBlake.jpg

What's the story behind the python Bob?? I'm assuming he wouldn't have been happy when you stood on him.

Originally Posted by twosheds

What's the story behind the python Bob?? I'm assuming he wouldn't have been happy when you stood on him.

It's a rubber one. My mate was trying to use it to train his dog not to go chasing tiger snakes and then it became a standing joke and had to be in almost every photo we took that weekend. The training did not work as said dog kept bringing snakes home. Eventually he never came home.

I posted this on a north American website (with no explanation) to feed their phobias about how a place dangerous Australia was with all that dangerous wildlife. I let them run with it and when I eventually told them it was fake they took it harder than I expected especially when I pointed out that the most dangerous animal on earth was other humans.

Originally Posted by BobL

It's highly variable and non linear depending on
Type of tree
How they were stored/Climactic conditions
How longs its been cut down
Size of tree

I milled some 25mm boards from a small (18") swamp mahogany near perth that had been cut down for 24 months and they were dry in less than 3 months.

OTOH this jarrah (it's a branch) was cut down in the 1930's lay in dense bush (with average rainfall 1000mm/year) until I milled it in 2010, two inch slabs still took two summers to dry out.
A 3" slab from the same branch I milled at the same time was just as dry as the 2"
When I cut the end off to trim the length several buckets of water poured out of the centre of the log

Cheers Bob. Will be interesting to see what I find.

Are you determining when its dry by using a moisture meter or ?

Originally Posted by RSD

Cheers Bob. Will be interesting to see what I find.

Are you determining when its dry by using a moisture meter or ?

Yep, my nominal "dry" for timber stored outside under cover to be resawn is 15%, it doesn't usually move that much after that, then it gets store inside for a few months. actual working dryness depends on use.

Originally Posted by BobL

Yep, my nominal "dry" for timber stored outside under cover to be resawn is 15%, it doesn't usually move that much after that, then it gets store inside for a few months. actual working dryness depends on use.

Cheers agian Bob - you are a mine of information! Any particular recommendations for which moisture meter to get?

Originally Posted by RSD

I know that the rule of thumb for slabs is one year per inch of thickness, but what is the rule of thumb for trees that have been down for a while?

The other issue with fallen timber is the onset of rot and/or fungal infection.

Originally Posted by BobL

It's a rubber one. My mate was trying to use it to train his dog not to go chasing tiger snakes and then it became a standing joke and had to be in almost every photo we took that weekend. The training did not work as said dog kept bringing snakes home. Eventually he never came home.

I posted this on a north American website (with no explanation) to feed their phobias about how a place dangerous Australia was with all that dangerous wildlife. I let them run with it and when I eventually told them it was fake they took it harder than I expected especially when I pointed out that the most dangerous animal on earth was other humans.

Must be pretty thin skinned over there Bob ,they don't understand when you're having a lighthearted jab at them,found this also in our travels & relatives we have over there.Cousin reckons he'll never understand Ozzies.

Originally Posted by BobL

It's a rubber one. My mate was trying to use it to train his dog not to go chasing tiger snakes and then it became a standing joke and had to be in almost every photo we took that weekend. The training did not work as said dog kept bringing snakes home. Eventually he never came home.

I showed the pic to my other half before reading the rest of the thread. Asked her if she thought you might have a problem when you got to the middle of the log. After a minute or two working out what I was on about, she spotted the snake, but then wanted to know what country it was in, because "that's not an Australian snake". Not just a pretty face then! Used to work at Cairns zoo, so she knows her nasties.

Apart from variability as Bob mentioned, a decent sized tree trunk will never be dry, seasoned yes but not dry. That is one of the main reasons they eventually rot, apart from the bugs, due to the moisture propagating the mould/spalting inside.

I helped drop an old 1.2m diameter huge redgum (that had a 10m straight section with fiddle) that was dead for 50 years (owner had lived there longer). The tree was dropped and was solid but moist (I guessed still >20%MC) in the middle and I advised the miller to seal the ends straight away or it would crack, he thought I was nuts due to its age being dead, so didn't. The next day all the up to 4m lengths were cracked with lots of huge full length cracks. The miller conceded they were stuffed, before resin slabs were a fashion, so docked them into 400mm lengths for firewood .

The older the "dead" of the tree the less it takes to dry, but it will still be wet, so more care needs to be taken when it's cut to avoid cracking. I tend to seal the ends as soon as a tree is cut no matter if it's dead or alive. I will then seal the ends again when it is milled into slabs.

Originally Posted by twosheds

What's the story behind the python Bob?? I'm assuming he wouldn't have been happy when you stood on him.

Originally Posted by BobL

It's a rubber one......

How could you mislead our American friends like that. Surely the correct response was "...It's only a tiger snake..."

Originally Posted by dai sensei

Apart from variability as Bob mentioned, a decent sized tree trunk will never be dry, seasoned yes but not dry. That is one of the main reasons they eventually rot, apart from the bugs, due to the moisture propagating the mould/spalting inside.

I helped drop an old 1.2m diameter huge redgum (that had a 10m straight section with fiddle) that was dead for 50 years (owner had lived there longer). The tree was dropped and was solid but moist (I guessed still >20%MC) in the middle and I advised the miller to seal the ends straight away or it would crack, he thought I was nuts due to its age being dead, so didn't. The next day all the up to 4m lengths were cracked with lots of huge full length cracks. The miller conceded they were stuffed, before resin slabs were a fashion, so docked them into 400mm lengths for firewood .

The older the "dead" of the tree the less it takes to dry, but it will still be wet, so more care needs to be taken when it's cut to avoid cracking. I tend to seal the ends as soon as a tree is cut no matter if it's dead or alive. I will then seal the ends again when it is milled into slabs.

What do people recommend for sealing? I've been using bees wax but I'm not sure if there are better options?

Originally Posted by RSD

What do people recommend for sealing? I've been using bees wax but I'm not sure if there are better options?

I just use water based paint. But never done it with jumbo logs like in Bob's photo. Also paint the end grain of slabs tp slow the drying.

I have used log sealer.
I used to be able to get it (Log Sealer) from Caltex in a 20litre container when we used to have Oil depot.Goes a long way still have about 4 litres left from buying it yrs ago
Perhaps some of the oil companies may still stock it ?link just as a suggestion but its around at ebay Timbecon etc.
LOG END SEALER CLEAR