Thread: Boxed heart

If it's an actual customer I find that most prefer the untreated timber... got that nice red look to it etc etc. We bang it through the borax, or give it a borax spray... but that's more with keeping the little black ants from moving in between the boards to get out the rain then anything. Sometimes someone wants fire retardant and then it gets the full borax loading.
Tradies mostly are switched on and don't much care - they buy on price.
Hardware stores and developers though want it to have been for a swim... the plan says H3 treated and thats what it has to be.

Interesting Carl that your numbers aren't too different from mine. We work on $200 a cube in the yard (max) for logs, though as we harvest most of them in house it's obviously not that bad, and there's often a fair bit of freight in it. Fuels more expensive up here and we often drag timber a long way... but my major competition is Parkside, Dale& Myers, and Gympie Timbers... I got a little freight advantage on them once it's sawn.

Recovery looks like mine on the S&B though I expected your landscape recovery to be a touch higher.

That S&B feedstock price made me wince though

I think a lot of people don't realise that a sawmill is approachable to buy from
most folks don't buy meat from a butcher or bread from a bakerthey go to the supermmarket
and the closest we got in this game is the big hardwares who are going to sell what they have as the best
stick of timber in the world and the customer believes every word.

There's a technique I've never much heard of in Australia called kerfing... originally came out of Japan I believe, though it was pretty common for big beam housing members when I was in the states . The practice is to pick the worst face on a beam... or the side that is not going to be visible to the eye in service... and then run a rip cut down it to half the depth of the beam. This allows for faster drying, and gives any drying stresses that develop a place to go to, rather then having to go to the timber surface to release the pressure.

Interestingly enough is that as a sawcut is classed as want under the grading rules... that cut has no bearing on the grading of that piece of timber unless it took up half the face or a third of the edge of the piece: ie the cut would not be a grade limiting feature. I tried it here and got a lot better success then those I didn't do in terms of not having surface cracks develop (this was in bluegum 250 x 250's). Thing is, despite the engineering theory behind it, and despite the grade being higher on the kerfed beams... try convincing a builder that it's better. Didn't worry me - I cut those for my own use but everyone that looked at them thought I was mad.

http://www.nordicforestresearch.org/.../38_Flaete.pdf

http://thecarpentryway.blogspot.com....1_archive.html

both cover the theory behind it.

Absolutely nothing wrong with boxed heart timber!!!some of the best posts you can buy will be boxed heart - but as always it is down to the miller to select the log for the timber being cut. Its great to box younger hardwoods with nice tight hearts for 150x150 BHP, but try boxing a 150x150 from a 600mm dia blackbutt log and you are just asking for trouble, but again no sawmiller worth the name would do this!!!!!

Having industry regulations is a tremendous idea and totally a necessity, but its the same old story, common sense is being bred out of decision making by legislation and solicitors, leaving people all too scared not to follow the exact letter of any plans - bloody ridiculous.... nuff said

Funny thing is Carl and I get to speak to the author sometimes on a weekly basis as he is setup 3 mins down the road from our new adventure.

John G, an interesting side note, the author has according to him, apparently 'patented' 'kerfing' posts.........

awwwwwwwwwwww $h!t. Does that mean I have to restump the house???

Originally Posted by Sigidi

Absolutely nothing wrong with boxed heart timber!!!some of the best posts you can buy will be boxed heart - but as always it is down to the miller to select the log for the timber being cut. Its great to box younger hardwoods with nice tight hearts for 150x150 BHP, but try boxing a 150x150 from a 600mm dia blackbutt log and you are just asking for trouble, but again no sawmiller worth the name would do this!!!!!

Having industry regulations is a tremendous idea and totally a necessity, but its the same old story, common sense is being bred out of decision making by legislation and solicitors, leaving people all too scared not to follow the exact letter of any plans - bloody ridiculous.... nuff said

Funny thing is Carl and I get to speak to the author sometimes on a weekly basis as he is setup 3 mins down the road from our new adventure.

John G, an interesting side note, the author has according to him, apparently 'patented' 'kerfing' posts.........

Maybe in the cheap end of the market boxed heart is ok. But the top end wont cop it. When I was buying we would not buy heart in, no matter what specie. It aint worth the risk. May I suggest that once your new venture is up and running and you are putting through some quantity, you will soon see why heart in is not such a good idea after all.

Patent kerfing? I dont think so. It has been around for at least thirty years to my knowledge.

Originally Posted by rustynail

Maybe in the cheap end of the market boxed heart is ok. But the top end wont cop it. When I was buying we would not buy heart in, no matter what specie. It aint worth the risk. May I suggest that once your new venture is up and running and you are putting through some quantity, you will soon see why heart in is not such a good idea after all.

I know heart has its problems - but a boxed heart post isn't a problem. After all how do you get something like a 300x300, never gonna happen without heart and it won't have any 'risk' in buying/selling


Patented - exactly why I said it, there isn't a smiley to show the tone of voice I had when writing that the author feels he patented kerfing

Originally Posted by Sigidi

I know heart has its problems - but a boxed heart post isn't a problem. After all how do you get something like a 300x300, never gonna happen without heart and it won't have any 'risk' in buying/selling


Patented - exactly why I said it, there isn't a smiley to show the tone of voice I had when writing that the author feels he patented kerfing

Depends what size logs you are cutting. To say heart isnt a problem can be a bit misleading. Often heart isnt a problem and often it is. Some of our Australian hardwoods have some of the best durability qualities of any timber. If the miller can enhance these qualities with cutting method, all the better.

Every bridge girder, mining timber post, pile etc I've ever seen has heart in. Every standing tree come to that. I've got no objection to heart in larger cross sectional sizes... regardless of size you have drying stresses in any large piece. I've got some heart free 8 x 8's in Queensland Maple air drying now and one of them has split like a bloody watermelon.

Having said that I believe that there has to be more wood then pith, AS2082 says not more then 33% pith, and defines pith as within a 50mmm radius of the center, which allows for boxed heart 175 x 175's. I don't tend to box heart under 200 x 200, even then there is a high "fail" rate. They still grade, but surface splits mar the appearance.

I'll box a 6 x 6 heart if I think it'll hold. Never have, but I will if I can. I'll also grade it landscape. My general standard of appraising timber is less "will it make grade under 2082" and more "would I use this in my own house?"

There are kerfed temple beams in Japan over a thousand years old!!! Will he get a royalty on them???

Originally Posted by rustynail

Depends what size logs you are cutting. To say heart isnt a problem can be a bit misleading. Often heart isnt a problem and often it is.

John, you are quite right most of the uses you mention are often heart in. These days it is more common than in the past. But that doesnt take away from the fact that heart in can and will, sooner or later be a factor in the degeneration of the piece. Applications where slow seasoning will be present helps a lot ie piles, mine props. Also this is vertical application which places less stress. As for bridge girders, there is not much alternative due to required size. Mind you, there would be increase in size allowance to compensate.

[QUOTE=Sigidi;1759774]Absolutely nothing wrong with boxed heart timber!!!some of the best posts you can buy will be boxed heart - but as always it is down to the miller to select the log for the timber being cut. Its great to box younger hardwoods with nice tight hearts for 150x150 BHP, but try boxing a 150x150 from a 600mm dia blackbutt log and you are just asking for trouble, but again no sawmiller worth the name would do this!!!!!

Here is some research supporting what Sigidi has said above and what I have said earlier.

2.4.1 Indicator properties of Eucalyptus grandis
Research done by Zitto et al. (2009) on the relationship between timber quality and the influence of moisture content above FSP and the presence of pith material on mechanical properties, in beams of fast-growing Argentinean E. grandis gave quite interesting results. Table 5 shows the results of 96 pairs of visually graded E. grandis boards which were graded into two classes, boards containing pith material and boards without pith material. The paired sample was also further divided into seasoned and unseasoned boards.
Table 5: Results of MOR and MOE corresponding to two visual grades and of seasoned and unseasoned E. grandis boards of dimension 1900 x 100 x 50 mm, age 14 years (Zitto et al. 2009).
Visual grade
Moisture condition
N
Mean (MPa)
Sdev (MPa)
Without pith
Seasoned
52 (sample size)
MOR
55.9 (MOR mean)
14 (Sdev)
MOE
12900 (MOE mean)
2400 (Sdev)
Unseasoned
52
MOR
41.9
8.4
MOE
9800
1500__________________________________________________________________________________________________________________________________
With pith
Seasoned
44
MOR
46.6
13.1
MOE
11400
1300
Unseasoned
44
MOR
40.5
7.5
MOE
9100
1400

Sorry but the table formatting wouldn't copy across - the entries in the brackets describe what the number is representing. For those without engineering background - MOR = modulus of rupture (basically ultimate strength), MOE = modulus of elasticity (basically stiffness)

The data shows less loss in MOR or MOE than one might expect for 'pith in' in this young material (below the line vs above the line). Timboz

Originally Posted by rustynail

John, you are quite right most of the uses you mention are often heart in. These days it is more common than in the past. But that doesnt take away from the fact that heart in can and will, sooner or later be a factor in the degeneration of the piece. Applications where slow seasoning will be present helps a lot ie piles, mine props. Also this is vertical application which places less stress. As for bridge girders, there is not much alternative due to required size. Mind you, there would be increase in size allowance to compensate.

Rustynail,

It is true that heart will undergo accelerated decay but the decay is predicated upon chemical degradation having taken place in the living (or whole dead) tree which renders that core timber more fungi/termite digestable. This chemical degradation occurs slowly in the living tree - hence tight heart in young trees and pipe/mudguts etc in old trees. The process only occurs in aqueous solution so trees that are young when milled then dried thoroughly have this process stopped. This supports the comments Sigidi and I have made about heart in material from younger trees being serviceable (assuming the cores are kept dry). Granted, this younger heart won't ultimately last as long as mature heartwood but it is a resource worth utilising.

Regards, Timboz