# Is this rot, bark inclusion or fungus discoloration?



## harum (Nov 25, 2013)

This board of hard maple seems to have a brown-colored core, judging by the annual rings. Is this bark inclusion or rot? The face grain of the brown patch has cracks along the grain visible on the second photo. If this is rot then some stabilization and extra sealng might be necessary.

Thank, h.


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## therealSteveN (Oct 29, 2016)

Pith. Quite the normal finding in Maple, both hard and soft.

Note you are at dead center.


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## CaptainKlutz (Apr 23, 2014)

+1 pith?

Note that some soft maple trees can/will have brown heartwood center, that is larger than typical pith found in most maple trees. It's commonly called country maple when lumber is streaked with brown. 
IME - Majority of country maple is from silver maple trees: 
https://www.woodworkerssource.com/lumber/hard-country-maple.html

Pith is generally softer, and contains more stress than regular heart or sap wood. Hard to tell from pictures if you have soft pith you want to avoid using for anything structural, or if it's prefectly good brown heartwood?

Cheers!


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## harum (Nov 25, 2013)

Steve, Cap, appreciate your responses! The diameter of the brown center is 5-6", which sounds too large for pith. Isn't pith only an inch or two in diameter? The brown core is as hard as the rest of the board, definitely not soft. However, one side had got quite a few thin and long cracks along the grain as in the photo. They might appear after drying?










In the link they sell similarly looking lumber called "country hard maple". They call the brown core heartwood.


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## therealSteveN (Oct 29, 2016)

Pith size will vary in each tree, so there isn't a hard, and fast rule on size. Plus as Cap'n mentioned it is often the brownish off-color of many a Maple. I wish all of it was that stark white color. That mixed wood is pretty prevalent. The rest of the center that could be off color is usually called Heartwood looking at a log from the butt end. The pic below is labeled to show differences through a tree, sizes of each of those areas will vary though.










I have some Oak I thought I got a screaming deal on at an auction once. It's all about 16" wide, but it has almost an 8" wide pith on every piece, except the top 2. The rest of it is hard as a rock though, but the guts is just fluff, totally useless. Nets some real nice 8" wide stuff glued back up, once I rip the fluff out of it. I have a couple of pieces of Walnut similar at 22" wide, You can easily snap them in 2. It was free though, so what I can use is really nice Sap wood.


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## pottz (Sep 15, 2015)

agree with pith, non of your woories.


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## harum (Nov 25, 2013)

Is the brown core on this image also pith? Are the words pith and heartwood used interchangeably for maples?










The image is from the link above.


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## therealSteveN (Oct 29, 2016)

It's going to be harder to tell with that pic having just the one slice. Successive cuts would point exactly to the pith. You are getting close, but the pith would be the board, or maybe 2 above the level you are at. .You can see this looking at the end grain. Note on the darker wood (likely heartwood) the swirled grain, that flattens out on the light wood goes to rift/QS.

Your other pic was closer to pith than this. The fact the spread was no bigger, than it is, made 2 of us look, and call it pith without seeing the rest. Thing is without seeing the entire tree, you can't tell exactly where pith stops, and heartwood starts. Unless you get a tell from the wood being weak at the mark you think is pith.

Point is, you aren't looking at rot, bark inclusion or fungus. That was your initial concern. If it is near pith, but wholly stable it is just off colored wood/heartwood.

No the words aren't interchangeable. Check that illustration pic, it clearly shows the relationship between pith, and heartwood. In the majority of cases pith alone, isn't too stable, and counting on it to be strong, and or stable is a mistake. Heartwood on the other hand can be used. Many woodworkers will eliminate it from Maple as off colored, and not "select" which is the off white. If you were to see the piece in the pic just above, and it was at a dealer who graded their wood correctly it would sell for much less than all white Maple. That said Curly Maple according to grade falls in the same grade as this, but is routinely sold for more than all White Maple. Yeah, go figure.

Thing is, if you like the look of "Country Maple" go for it, it should cost less, but sometimes when they put fancy names on off grade stock, that isn't what you always see happen.

What you are showing are relatively sound looking boards. This is the ugly side of pith, and what I am talking about when I say you can crack a board in two, along the pith line. If either of these 2 were sawn to 3/4" as your stock is, most of the work of breaking it in two, would already be done for you.


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## harum (Nov 25, 2013)

Thank, Steve, lots of info. I'll have to re-read it a few times. Yes, I hadn't known that hard maple had brown heartwood, hence my concerns. I appreciate all the responses. My thinking behind calling the brown core heartwood was: if pith has a much smaller radius compared to heartwood and has no stability then in my photo the brown stuff, which is 6" in diameter and as hard as the rest, is heartwood because if this is pith, where then is the heartwood.


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## CaptainKlutz (Apr 23, 2014)

> It s going to be harder to tell with that pic having just the one slice.
> Successive cuts would point exactly to the pith.
> - therealSteveN


+1 difficult topic to discuss with just one board, and one pic.
IMHO
If your board is from hard sugar maple (that is mostly white heart & sap wood, then the brown color wood is center pith. 
If you have a slab of silver maple (with brown heartwood section), then brown color wood is usable heartwood.

You might be able determine the species with careful end grain analysis. But short of seeing more boards from same tree, it is hard to know exact composition of your 'brown' maple.
References:
https://www.wood-database.com/hardwoods/sapindaceae/acer/
http://hobbithouseinc.com/personal/woodpics/maple,%20soft.htm

Best luck.


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## Tony_S (Dec 16, 2009)

Just looks like simple heartwood with the very early stages of what I would call heart rot(the cracking).


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## Lazyman (Aug 8, 2014)

Pith is just the spongy growth at the very center that is inside the first year's growth. Cut open a twig that is in its first couple of years growth and the stuff in the center is the pith. The wood that surrounds the pith is usually considered juvenile wood and is the first to die and turn into heartwood (which is what the dark area in your picture appears to be). When someone says to cut out the pith what they really mean is to cut out the center of the tree, especially the juvenile wood or first 5-10 years of rings at the core, because the juvenile wood shrinks more than mature wood and by removing it, the wood is less prone to cracking and warping.

BTW, heartwood occurs as the cells in the inner rings die and tannin and other substances start to concentrate there making it darker and often more dense and more resistant to rot.


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