Thread: bad storage

okayyyy...

Lack of airflow in drying timber stacks tends to result in mould or rot. It's too much airflow that causes drying degrade.
Heat without airflow = sauna, not a condition likely to cause checks and cracks.
Heat with airflow = kiln type environment. Mine runs at 60 Celsius with fans circulating air continuously and I'd say that's about normal for a hardwood kiln... ive never been inside any shed as hot as the inside of a kiln but not impossible I guess.
Airflow without heat = drying environment, how rapid the drying depends on how fast the wind and how cold, but timber can over dry in those conditions.

It would be nice if you could get a moisture reading of both the messmate and Blackwood so we could rule out over drying.
It would also be nice if you could give some indication of what you mean by "as green as" when it went in. Had leaves on it yesterday / logs on the ground a fortnight / got sawn and sat about three days in a loose stack... All those can be useful to work out what went wrong.

question for John

is Messmate one of the "Tassie Oak" species?
could the problem be how the wood was cut ?

John, I reckon the logs would have been on the ground (after being felled) for about a month before I cut them, they were only slabbed by a Bandsaw mill, about 50-60mm thick

Something I forgot to mention is they were stood up or rested against the shed wall on their sides, so I don't know is that put stresses on the timber.

I also wonder if it was only slabs from the heartwood and either side of that.

I have moisture meter so I'll try that, I have cut up some of the split timber for firewood, but it still seems green inside, yer I know rule of thumb is 1" per year for drying.

Hope that helps?

Originally Posted by ian

question for John

is Messmate one of the "Tassie Oak" species?
could the problem be how the wood was cut ?

Moren likely. I wasn't even looking at that - to me "messmate" means Gympie Messmate and I didnt even think about it being the "other" messmate *headdesk*

Per Bootle "slow in drying and likely to check. Some collapse occurs. Shrinakage about 5% radial, 11% tangental"

Probably the thing right there, bit of too rapid drying at the start would have opened microchecks everywhere and then as it dropped water shes opened up like a split watermelon.

Originally Posted by Not enough!!

John, I reckon the logs would have been on the ground (after being felled) for about a month before I cut them, they were only slabbed by a Bandsaw mill, about 50-60mm thick

Something I forgot to mention is they were stood up or rested against the shed wall on their sides, so I don't know is that put stresses on the timber.

I also wonder if it was only slabs from the heartwood and either side of that.

I have moisture meter so I'll try that, I have cut up some of the split timber for firewood, but it still seems green inside, yer I know rule of thumb is 1" per year for drying.

Hope that helps?

I'd say ian probably hit the nail on the head. Check prone species take a lot of PITA care to dry intact.

Messmate in Tassie is Obliqua, one of several timbers that fall under the banner of Tasmanian Oak.
Requires slow drying as prone to checking and collapse. When kiln dried, reconditioning is most benificial.

Originally Posted by rustynail

Messmate in Tassie is Obliqua, one of several timbers that fall under the banner of Tasmanian Oak.
Requires slow drying as prone to checking and collapse. When kiln dried, reconditioning is most benificial.

my understanding is that the Tassie Oaks are mostly quarter sawn because of the wood's propensity to check while drying.

Originally Posted by ian

my understanding is that the Tassie Oaks are mostly quarter sawn because of the wood's propensity to check while drying.

Theres two reasons that The Tassie Oaks and any other high shrinkage collapse prone timbers are quarter sawn for appearance products (purely structural product doesn't matter so much because its just as strong - just uglier)

First is how the shrinkage affects it. If we cut a backsawn board based on those numbers above at 150 x 25 nominal, after drying shrinkage it'd wind up around (roughly) 135 x 23mm or so. (10% shrinkage is on the wide face of the board) If we quartersaw the same size with the same numbers we get about 142 x 22.5mm (5% shrinkage on the wide face). If the object is to produce a standard 135 x 19mm T&G or DAR board you'll get more yield by cutting quartersawn, because its easier to cut a thicker board to cover the shrinkage then it is to cut a wider one.

The main reason however is how it responds to steam reconditioning. In steam reconditioning we put the timber into a chamber when its at around 20% MC and pump in wet steam until it swells the boards back up to nominal dimension again. This evens out the variable shrinkage associated with collapse and gets rid of the washboard effect, and it also closes up any checks on the radial (quartersawn) face, usually to the bottom of the check. Checks on the backsawn face will only superficially close up: because of the way the timber swells its only the surface closes and as soon as they get dressed (post kiln) a lot of the checks are still visible. After steam reconditioning the timber goes into a kiln (or can be air dried) to finish it.

Note that in this the checks (and any internal honeycomb) is still there. Its just closed up so you cant see the thing, which is why theres no difference in the structural grade of the board against a backsawn one.

IMG_20151215_150855.jpgIMG_20151215_150953.jpg

These pictures are of a collapse prone species cut here. You can see by the ends of the pack how the internal checks have followed the radial grain, which is why they close up better under steam. Or another way to look at it is this is what your Tassie Oak/ Vic Ash looks like before it gets reconditioned. Afterwards mostly you dont ever know the cracks were there. To put a number on the degree of variable shrinkage, that larger board in the other picture is a 200 x 100, or at least it was when cut. Eyeball number there would be 20mm of shrinkage on that one edge of the board, but thats how collapse looks. Pop it back out in a steam chamber, or just resaw it back to a "square" size, prolly 175 x 75 by the look, and its a perfectly acceptable F17 timber.

Originally Posted by rustynail

Messmate in Tassie is Obliqua, one of several timbers that fall under the banner of Tasmanian Oak.
Requires slow drying as prone to checking and collapse. When kiln dried, reconditioning is most benificial.

Down south east of south oz. Its E. Baxterii. I think thats the dpelling. And I must say I've had a lot of trouble with collapse.
Tim

Originally Posted by Tim Creeper

Down south east of south oz. Its E. Baxterii. I think thats the dpelling. And I must say I've had a lot of trouble with collapse.
Tim

I think it has one i. Common name Brown Stringy. Dont think it grows in Tasmania.