Newbie posted today about a herringbone table he made (of solid wood).   Can we have a poll to decide how long before it blows apart?   

 

I get December 2024

 

those mitered corners will go first.  July 2024, once it gets warm and humid.

Title of a newsletter I used to get from a wood technology school was titled "Wood Moves".   Yes it does. 

18 minutes ago, 4DThinker said:

Title of a newsletter I used to get from a wood technology school was titled "Wood Moves".   Yes it does. 

It's an issue I see all the time on beginner projects.   And I have seen a few tables (made in Asia) that have had cracks from one end to the other.  One customer told me, "We heard what we thought was a gunshot in the middle of the night.  When we came out in the morning, there was this huge crack in the dining table from one end to the other."  And frequently raised panel doors and sides with "suntan lines" that needed to be fixed before the piece was even sold.

Working on a post for my blog about a chess table I made in my first college workshop class.  Walnut and pecan squares for the 8/8 grid with grain all running the same direction.  Surrounded by a 2" wide walnut mitered frame.  Moved to a new townhouse in Harvester MO and the first big rain we had flooded the basement.  High humidity buckled the grid until the dowelled corners of the frame finally gave out.  My first lesson in how much wood will expand when the humidity spikes.  

Edited March 10, 20242 yr by 4DThinker

I saw Ben Napier (on the HG show "Home Town") make a much smaller one than that but with the same grain layout...I wondered at the time how long it would last. He's a guy that should know better, or at least he seems to be a guy who should know better.

Edited March 10, 20242 yr by Fred W. Hargis Jr

When I had my woodworking and restoration business in the mid 80's to early 90's we built a fair number of custom pieces of furniture.  I had a sign posted in plain sight in my office - There are two rules to wood movement: Rule #1 is that wood moves.  Rule #2 is that you and I can't change Rule #1

16 hours ago, Fred W. Hargis Jr said:

I saw Ben Napier (on the HG show "Home Town") make a much smaller one than that but with the same grain layout...I wondered at the time how long it would last. He's a guy that should know better, or at least he seems to be a guy who should know better.

I don't think he is as sharp as they try to make him look.

You may be correct, I've not seen the show that many times and then I usually only watch when he's in that shop he has.

On 3/9/2024 at 2:20 PM, kmealy said:

Newbie posted today about a herringbone table he made (of solid wood).

Where is this posted Keith?

15 hours ago, John Morris said:

Where is this posted Keith?

IIRC, it is "Woodworking for Beginners" on Facebook

 

This is where I would fail miserably on larger wood projects. I do not have a great understanding on the expected movement and or the best way to prevent it from damaging a project. I envy the wisdom experienced woodworkers have with the subject. 

Edited March 20, 20242 yr by aaronc

To follow up all of the comments I have a question.

If that table top were made from strips of plywood, would there be an issue with expansion?  My brain wants to say no.

How about the solid wood edging with mitered corners, any issue there if the top itself is plywood?

My opinion: no, and no. I've done several tops with plywood panels and trimmed wit hardwood....nary a problem.

On 3/10/2024 at 6:21 AM, Fred W. Hargis Jr said:

I saw Ben Napier (on the HG show "Home Town") make a much smaller one than that but with the same grain layout...I wondered at the time how long it would last. He's a guy that should know better, or at least he seems to be a guy who should know better.

I would question everything he makes.  Apparently Powermatic has a different opinion.  He started with a shop with minimal tools and now his shop is full of the Gold Standard.   Danl 

17 hours ago, aaronc said:

This is where I would fail miserably on larger wood projects. I do not have a great understanding on the expected movement and or the best way to prevent it from damaging a project. I envy the wisdom experienced woodworkers have with the subject. 

Wood expands very little along the grain (i.e., length)  It expands radially (from the center out) and tangentially (around the growth rings).  In most species, the tangential is about twice the radial.   This manifests in two things:

• Quartersawn stock (with the rings vertically, or nearly so) has less side to side contraction, but mostly in thickness, where it matters less
• If you take a section of a log and dry it, it will usually crack into a wedge-shaped opening because the tangential is moving more than the radial

another thing: 

• Flatsawn wood will tend to cup toward the outside of the tree when the wood gets drier.  So when I make drawers, my mantra is "inside of the drawer, outside of the tree" so that the top and bottom of the drawer sides do not pull away.

 

Page 306 ff. discuss wood movement.  www.fpl.fs.usda.gov/documnts/fplgtr/fpl_gtr190.pdf 

wood is kind of like us:  we don't get taller, but we might get fatter or skinnier as time goes by.

3 hours ago, DAB said:

wood is kind of like us:  we don't get taller, but we might get fatter or skinnier as time goes by.

 

 

 

That cleared things right up for me...I get it now. It was right in front of me all these years 

An evolved adaptation to gravity. Then a little homage paid to geometry.  Circumference =Pi (3.14ish) x diameter.  Tree adds a new 1/16" ring, getting 1/8" bigger in static diameter. The circumference though grew .125 x Pi or 0.39269908169" .  Moisture intake has the same ratio effect, swelling a tree 3+ more times in circumference than diameter.  So face cut boards expand/contract up to 3 times more than boards cut radially through the growth rings.  Seen it happen many times as seasons changed during a semester of furniture design classes.