You cannot stop wood movement, but you must account for it.

 

Builder writes: "This was a more rustic build on an indoor table top with kiln dried spruce.  ... The movement seems excessive for 3 months in Florida and the fact that the glue joint is where the seperation [sic] took place."   Nope,  

 

 

Edited January 8, 20233 yr by kmealy

There's something else going on there too, there is hardly any glue there. There is no way those biscuits would pull away if those slots were flooded with glue, and if he flooded the long grain edges with glue before they clamped it up, if that was a properly glued up joint that shouldn't have happened IMHO.

Depends how the center area was joined to the end boards and other side.  The center field obviously shrank,  That it pulled away from one biscuit jointed edge implies it is better held on the other side and/or middle.  Wrapping a solid wood panel with a mitered frame is a classic mistake I had to repeatedly discourage my students from doing. I made that same mistake with a chess board table I made when a student. Solid field of walnut and pecan squares wrapped with a mitered walnut frame.  This top blew apart when the basement flooded in the townhouse I was living in and humidity jumped to 99%. Center field swelled up and broke the mitered frame apart. 

4D

1 hour ago, 4DThinker said:

Center field swelled up and broke the mitered frame apart.

In this table example, that is where I would have thought the blow up would occur, the weakest link in that table is the mitered corners. It's almost as if there was barely any glue at all in that joint that separated, if there was sufficient glue, the wood fibers would be shredded all over the place, instead you see a virtually clean pull away which would indicate little glue was used.

 

Since it appears the field of the table contracted? If glued up properly, I'd expect cracks instead of failure at the glue joints.

You're right in thinking the glue would have held but the board would have split.  I don't know how old the table is, but I've lived long enough to see old glue break down and become why old furniture comes apart at the joints.  

Must have built it in the open air shop and then placed it in the air conditioned home.

13 minutes ago, HandyDan said:

Must have built it in the open air shop and then placed it in the air conditioned home.

Living in the Southwest does have it's advantages such as consistent low humidity environments, I often see some of the folks here, taking great consideration for movement because in the midwest and south, you really have to consider this don't you?

While I'll consider movement when I build anything, it's not a priority, and I've never had a failure due to movement. Now, that being said, if we move to the South when I retire, I may have some serious issues with everything I've built for our home!

2 minutes ago, John Morris said:

taking great consideration for movement because in the midwest and south, you really have to consider this don't you?

 

I have a Crack in my Grandfather Clock base during the winter and it broke in the board not the joint.  It is Southern Pine.  I have a desk top that has never moved and by rights it should have.  It is White Oak.  I sealed the underside of the desk top but did not seal the inside of the clock base.  Both were built in my air conditioned basement shop.  I feel there are many factors involved and it is hit or miss sometimes.

7 minutes ago, HandyDan said:

and it is hit or miss sometimes.

That makes sense Dan, not too mention no two woods are the same, grain can be a mystery right? It does what it wants to do, with no warning, regardless of all precautions taken?

 

1 minute ago, John Morris said:

It does what it wants to do, with no warning, regardless of all precautions taken?

 

Agreed.  It adds character.

11 minutes ago, HandyDan said:

It adds character.

That's what all of us hacks say about the stuff we build.

59 minutes ago, HandyDan said:

Must have built it in the open air shop and then placed it in the air conditioned home.

concur.

 

wood was nice and happy with the outdoor humidity levels, got built, put in an AC house, AC pulled the moisture out of the wood and it shrank and broke the joint.

 

at least here in Santa Fe, it's dry outside and inside.

 

but still, as others have mentioned, poor design.  wood wants to be free, let it move.

That’s a real bummer. We experienced that when we first moved to the desert and built a few items that we took over to the coast. It was the exact same scenario, a mitered border on a main body. It’s pretty impressive how far wood will expand. 
Paul

Definite wood contraction AND bad glue up.

15 hours ago, John Morris said:

There's something else going on there too, there is hardly any glue there. There is no way those biscuits would pull away if those slots were flooded with glue, and if he flooded the long grain edges with glue before they clamped it up, if that was a properly glued up joint that shouldn't have happened IMHO.

Agreed that a properly glued joint will be stronger than the surrounding wood.

 

However there are two things going on here:

1.  It looks like construction lumber was used that is typically not dried to EMC (Equilibrium Moisture Content), the internal moisture level consistent with the external moisture level.  Consider that probably in recent months, even in Florida, some heat will be on, lowering the relative humidity in the home.
2. Wood expands in three directions (a) along the growth rings (know as tangential).  This is the most, usually about twice (b) from the center out (radial).  And (c) along the grain (linear) the way the tree grows tall, and that is hardly at all. 

So, here in this guy's table, you have some mostly flat-sawn wood, wet, that will shrink a lot across the board.  It is being constricted by the mitered end (long grain).  So it builds up stresses to the point where the weak point, in this case, the bad glue line, gives.    If it was a good glue joint, it would have split somewhere along the boards.

 

I have occasionally had to explain to customers why their breadboard ends are sticking out.  I'm not sure they understood my explanation other than, "If it didn't, your table would have a big crack in it."

 

I think I've said before that this is very common with Asian-made furniture.  I'd see lots of cracks and "tan lines" in shrunken panels.

 

Ignore wood movement at your peril.   The linked to Wood article was very good.  https://www.woodmagazine.com/woodworking-how-to/wood-preparation/dealing-with-wood-movement?fbclid=IwAR3w1W1XKFUE_JA9xCQrh-2AQIBxDIMzDX-N0wj6rmXJSWfLhdRASS_u5h8

client:  i want a bread board end!

 

me:  no you don't.....

Have to agree it is a bad design with construction lumber . We know nothing about the lumber but even if it was dry at build time , which I Doubt, it was doomed by that corner joint. I have destroyed some of my glue joints on jigs or temporary shelving and sometimes with distress , read a big hammer, the glue joint does break

you might have a chance with this design if you had quarter sawn lumber.  and if it was white oak, it would also look real cool.

Edited January 8, 20233 yr by DAB

3 hours ago, DAB said:

you might have a chance with this design if you had quarter sawn lumber.  and if it was white oak, it would also look real cool.

 

Yes, per the above, quarter sawn  expands more in thickness, where it usually does not matter so much, than width.

 

Edited January 9, 20233 yr by kmealy

On 1/8/2023 at 10:12 AM, John Morris said:

Living in the Southwest does have it's advantages such as consistent low humidity environments, I often see some of the folks here, taking great consideration for movement because in the midwest and south, you really have to consider this don't you?

While I'll consider movement when I build anything, it's not a priority, and I've never had a failure due to movement. Now, that being said, if we move to the South when I retire, I may have some serious issues with everything I've built for our home!

Don’t worry every time you step outside the humidity will remind you 

 

I do have to say I enjoy reading these discussions as I learn from all of you. Thank you

Edited January 14, 20233 yr by KevTN