# Characteristics of sinker wood



## TurkeyWood (Oct 1, 2021)

I recently purchased a piece of bullet tree (_Bucida buceras_). It’s crazy hard and heavy but the janka and density of the species is only 1,970 and 57 lbs/ft cubed. Does sinker wood take on different characteristics than the normal dried wood of the same species?


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## phinds (Oct 1, 2021)

Janka is not a density scale, it is a hardness scale. The two are not the same thing

The USDA lists Budida buceras as having a Janka hardness of 2,340. Where did you get 1,970? The USDA agrees w/ your 57lbs/cuft.



Bucida buceras



Sinker wood obviously has at least one characteristic that is different than the normal wood and that is that its density is higher. Kind of obvious. As to changes in the cell structure, no it's not different but the cells CAN get infused with minerals from the water. I think once sinker wood is properly dried, it's pretty much the same as regular wood except for color which is likely to be at least a bit different and the density can be a bit high if it has picked up minerals.

@Mr. Peet anything to add?

Reactions: Great Post 1 | Informative 1


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## Gonzalodqa (Oct 1, 2021)

Are you sure is completely dry? 
I find kinds difficult to actually test harness without proper species data I can only tell if my nail can dent the surface or not.
I have a sample of Bucida buceras and I don’t find it particularly hard or heavy


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## TurkeyWood (Oct 1, 2021)

phinds said:


> Janka is not a density scale, it is a hardness scale. The two are not the same thing
> 
> The USDA lists Budida buceras as having a Janka hardness of 2,340. Where did you get 1,970? The USDA agrees w/ your 57lbs/cuft.
> 
> ...


Not sure how you interpreted my post, I was commenting on Janka hardness and density. I thought the Janka rating was a little low but now I can’t remember where I found it. Evidently this stuff has picked up a lot of minerals because it’s super heavy for it’s size. I cut it today but didn’t test the moisture, although it seems dry to me.


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## Mr. Peet (Oct 1, 2021)

Well, _Bucida buceras_ is stout. Some have it in the _Termanalia_ genus. It is called 'Juncaro', 'Black olive' and 'Oxhorn bucida' often. Specific gravity runs around 0.93, 76 pounds per cubic foot. This is much higher than the 57lbs/cuft. Paul has. Janka ?, not sure I have that noted anywhere. A USA native to southern Florida. As for under water, susceptible to marine borers. 

Now the name 'Bullet tree' is a name common to _Mimusops elengi _but more common in the USA to _Manilkara bidentata_. Both are called 'Bulletwood' as well. _Manilkara bidentata_ is South American and common in the decking trade, 3130 Janka. 

Where did 1,970 come from, maybe just a misread and it was 1,970 kg/m3 of a wood he was reading up on.

As for sinker wood, Paul was quick with common sense, but not always correct in stating so. Higher density woods are more likely to become sinker wood for many reasons. The higher density wood sets lower in the water with less volume above the water. As logs roll and are moved, the air in the log is released. Over time the log absorbs water in the voids, increasing weight until the time it sinks.

Once under, the wood has many venues of action. Water can dissolve minerals and leach them from the wood. Amazingly, the reverse can happen as well where water transports dissolved minerals and deposits them in the wood. Sometimes oxygen deprived water protects the wood, halts rot and staining. Sometimes the water promotes staining, or marine bores. It is just not the water, but also the parent materials of the soil and rock feeding the water and that on which the water resides.

As wood rots, the lignin can brake down, weakening wood and lowering density (off-gas). Whole other ball of wacks....

Reactions: Great Post 1 | Informative 4


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## phinds (Oct 1, 2021)

Mr. Peet said:


> Specific gravity runs around 0.93, 76 pounds per cubic foot.


Uh ... you might want to rethink that 76


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## Mr. Peet (Oct 2, 2021)

phinds said:


> Uh ... you might want to rethink that 76


That is how it was listed for the USDA data sheets as well as IWCS tree sheets. Wonder again if it is a typo and 67 or other is more correct..?.. Or it simply has a huge range....


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## phinds (Oct 2, 2021)

Mr. Peet said:


> That is how it was listed for the USDA data sheets as well as IWCS tree sheets. Wonder again if it is a typo and 67 or other is more correct..?.. Or it simply has a huge range....


A specific gravity of .93 implies a density of .93*62.42 = 58. The USDA lists 69. I stated above that it agreed w/ his 57lbs/cuft but that was just a quick head calc of .93 * 62. I glossed over the 69 because I was focused on his apparently incorrect statement about the Janka value. Where are you getting the 76?

Also, even the 69 seems definitely wrong since as I recall, oxhorn does float (which is consistent with the .93 => 57/58).


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## TurkeyWood (Oct 2, 2021)

This is all good info folks.


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## phinds (Oct 2, 2021)

TurkeyWood said:


> This is all good info folks.


Nah, not really. Mark and I just make stuff up to impress people.

Reactions: Funny 4


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## Mr. Peet (Oct 2, 2021)

phinds said:


> A specific gravity of .93 implies a density of .93*62.42 = 58. The USDA lists 69. I stated above that it agreed w/ his 57lbs/cuft but that was just a quick head calc of .93 * 62. I glossed over the 69 because I was focused on his apparently incorrect statement about the Janka value. Where are you getting the 76?
> 
> Also, even the 69 seems definitely wrong since as I recall, oxhorn does float (which is consistent with the .93 => 57/58).
> View attachment 216949


The 76 came off of a USDA data sheet, 1974 (year). That is why I wondered if they were reciprocated / reversed numbers?..?..

Reactions: Informative 1


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## chatometry (Oct 4, 2021)

Sorry for the silly question... What are "sinker" logs? Are they logs transported by floating which, for some reason, end up sinking? Are they dead trees washed away by rivers and then sunk in their bed?
I guess submerged trees like those within the Panama canal or @Paul Veerkamp 's green osage, which (correct me if I'm wrong) die due to flooding, are a different category...right?
What about belizean mahogany mentioned by @Arn213 ?

Reactions: Like 1


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## Arn213 (Oct 4, 2021)

^Sinkers do have 2 definitions- logs that sink on it’s way to the mill and a very dense wood that sinks in water…….Paul & Mark basically covered that above.


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## phinds (Oct 4, 2021)

chatometry said:


> Sorry for the silly question... What are "sinker" logs? Are they logs transported by floating which, for some reason, end up sinking?


Yes.

Mud cured osage is a different thing.

Reactions: Like 1 | Agree 1


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