# Question on wood movement on a round table



## Wesley75 (Oct 29, 2019)

Edit: Project's (finally) finished Radial butcher block table, thanks for the help everyone!

Hi All,

I'm planning to build a round 'butcher block' style dining room table. It will be 5 feet in diameter, and just to make life interesting I plan to join the staves radially instead of the standard parallel assembly you see on counter-tops. I've attached a sketch of the assembly.

The individual pieces will be 1" inch wide, 1 1/4" thick, and range from 30" in length to 10" at the edge.

My main concern is wood movement potentially cracking the joints. I will probably drill a 1" hole in the center to allow the table to expand and contract with the seasons, but I am not sure if that will be enough to prevent splitting long-term.

I've toyed with the idea of drilling pin-holes where the shorter staves slot between the longer ones to allow further 'room to breath' but would like to avoid drilling more holes in the tabletop if possible.

What do you guys think? Is there a way to manage the wood movement in this type of project or is it doomed to split?

Best,


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## mmwood_1 (Oct 24, 2007)

It's an interesting question. I've never done or seen anything like that made with solid wood, usually it would be veneered, presumably due to movement issues. I could not say one way or another with any certainty. I've seen constructions where people were sure it would do this or that, and they didn't. If you're going to do it though, I would have 2 suggestions, which you may already know. (I am guessing that due to the complexity of the design and the precision required that you are an experienced woodworker, but you never know)



First, try to have all the pieces be edge grain, or quartersawn. As most movement occurs across the face of the grain, quartersawn will help reduce the amount of movement across the table top.


Second, the temperature and humidity in the room where this piece will live should be as stable as possible, year 'round. That will also help reduce the factors that cause movement.


Otherwise, good luck.


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## Tool Agnostic (Aug 13, 2017)

Use a stable base with veneer instead of solid wood?


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## woodnthings (Jan 24, 2009)

*radial wood movement .......*

Typically, with parallel planks glued up together, the movement is across the grain. With the pieces being radially glued up, the movement will be uniformly distributed around the circumference. Each piece is small so there will be every little movement on each piece. So, I don't think there will really be much of an issue, but that's just my opinion. 

The only radially sectioned table I'm familiar with is this one:
http://waterfront-woods.com/


http://waterfront-woods.com/Projects/schannotablediscussion.htm


http://www.waterfront-woods.com/Projects/RoundTable/TableBlog.html






:vs_cool:


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## GeorgeC (Jul 30, 2008)

I agree that wood movement will probably be minimal.


What I want to hear, after you are complete, is how many swear words you used when cutting all of those little triangles.


George


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## gmercer_48083 (Apr 9, 2016)

I would think it would destroy itself. The circumference is like a glued up cross grain of 188". I think it would move quite a lot. Not to mention the different amounts of movement as it moves at lesser diameters in your glue up. Although quarter sawn lessens seasonal wood movement, it doesn't eliminate it.


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## woodnthings (Jan 24, 2009)

*I don't see this .....*



gmercer_48083 said:


> I would think it would destroy itself. *The circumference is like a glued up cross grain of 188*". I think it would move quite a lot. Not to mention the different amounts of movement as it moves at lesser diameters in your glue up. Although quarter sawn lessens seasonal wood movement, it doesn't eliminate it.



You can't stack all the dimensions in a straight line. They are moving simultaneously and in unison. It's like centrifugal force on a rotating wheel, it will expand or contract at the same rate..... just my WAG "theory' ...


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## FrankC (Aug 24, 2012)

Interesting concept, no idea about expansion, could have an argument either way, my concern is that you don't see many tables of that design, either they are just too difficult to make or they are not known to be stable. Something I would definitely do a bit of research on from reliable sources before fitting all those parts together.


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## DrRobert (Apr 27, 2015)

You won't have a problem the way you're doing it. I don't think considering the cumulative miniscule movement in a 1" wide board.



Obviously if the table has larger wedges of solid lumber then there would be a problem. Unless, of course the boards are oriented so the long grain goes the shorter distance.



They are veneered they've been doing them like that for hundreds of years.


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## Wesley75 (Oct 29, 2019)

I'll keep a tally going 
Though to be honest I think the real profanity will be when I clamp this monstrosity up.


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## Wesley75 (Oct 29, 2019)

FrankC said:


> Interesting concept, no idea about expansion, could have an argument either way, my concern is that you don't see many tables of that design, either they are just too difficult to make or they are not known to be stable. Something I would definitely do a bit of research on from reliable sources before fitting all those parts together.


I've tried quite a few experienced wood workers in my area and unfortunately no one really seems to have a confident answer either way (which is why I am reaching out here :smile2. I'm pretty sure having a solid table top done this way would destroy itself, even quarter sawn staves would move enough to put a lot of pressure on the center. But I 'think' drilling out the center itself should let it 'breath': the movement would be 90 degrees to the radius, which would just cause the table to dilate... I hope... 

Wouldn't mind some feedback before embarking on this though.


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## Wesley75 (Oct 29, 2019)

woodnthings said:


> Typically, with parallel planks glued up together, the movement is across the grain. With the pieces being radially glued up, the movement will be uniformly distributed around the circumference. Each piece is small so there will be every little movement on each piece. So, I don't think there will really be much of an issue, but that's just my opinion.
> 
> The only radially sectioned table I'm familiar with is this one:
> 
> :vs_cool:


Thanks for the advice! I do think that the movement would be enough to cause problems if the center was fixed. But I'm hoping to avoid that by drilling out the center.

I had looking into some of these tables. beautiful stuff, but they use veneers while I was hoping for the solid wood effect.


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## Wesley75 (Oct 29, 2019)

woodnthings said:


> You can't stack all the dimensions in a straight line. They are moving simultaneously and in unison. It's like centrifugal force on a rotating wheel, it will expand or contract at the same rate..... just my WAG "theory' ...


Actually I agree with gmercer on this one. its not quite like a rotating wheel since the pieces don't 'want' to be longer. The movement is along the width of the piece - pushing the staves appart - but pushing them apart then stretches them lengthwise which is where it would get hairy. I thing the center would pull itself appart without a hole drilled through, but not sure if it would be enough


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## Wesley75 (Oct 29, 2019)

woodnthings said:


> You can't stack all the dimensions in a straight line. They are moving simultaneously and in unison. It's like centrifugal force on a rotating wheel, it will expand or contract at the same rate..... just my WAG "theory' ...





GeorgeC said:


> I agree that wood movement will probably be minimal.
> 
> 
> What I want to hear, after you are complete, is how many swear words you used when cutting all of those little triangles.
> ...


I'll keep a tally going 
Though to be honest I think the real profanity will be when I clamp this monstrosity up.

Will post photos once it's done, but that may be a while


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## woodnthings (Jan 24, 2009)

*Are you good at Trig?*



Wesley75 said:


> Actually I agree with gmercer on this one. its not quite like a rotating wheel since the pieces don't 'want' to be longer. The movement is along the width of the piece - pushing the staves apart - but pushing them apart then stretches them lengthwise which is where it would get hairy. I thing the center would pull itself apart without a hole drilled through, but not sure if it would be enough



I hear what you are saying, BUT the opposite side and hypotenuse of the triangle which "may" change dimensions is the factor. With pieces that aren't very wide, I don't envision that being a very great issue. There will be no change in the lengths, only across very small widths, so again, I don't see any issues. Build it we will have another conversation..... :vs_OMG:


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## FrankC (Aug 24, 2012)

My problem is that as far as I can see there is no difference between the sum of the movement of several narrow boards and that of one wide board equal to the combined width of the group.

There appears to be a lot of work involved, most similar designs are veneered, and so far all you have got is "I can't see why nots", no one is speaking from experience, so take the advice for what it is worth, it may be okay, maybe not and you have the only horse in the race.


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## gmercer_48083 (Apr 9, 2016)

My thought is that the outer rim of the disk will expand and contract the most. Like spreading your fingers.


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## Tony B (Jul 30, 2008)

Interesting thoughts on the subject. 
Im thinking, that during the shrinking season the boards could split apart.
During the expansion season, since everything is radial, the top would compress itself. This would force it to squeeze and expand in the longitudinal direction, so, like others here, I dunno. Someone mentioned that the individual pieces weren't that big so expansion would be minimal. I disagree with that because when they are glued up, it will act like one big board. However, it might be able to survive it all with no problem at all. 
Me personally, I would not invest that kind of time to build it and just wait to see what happens. 
Do we have any structural engineers here????????????????


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## TimPa (Jan 27, 2010)

we have to agree that expansion and contraction will take place. because the pieces are small and glued at angles will not keep it from happening, or make it less. IF i were a betting man, i'd bet the farm it will have issues (ones almost impossible to fix)- much dependent on the climate and atmosphere it is located in over time.

i am in the camp of a stable substrate and veneering the top - it will still be a challenge and have beautiful results.


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## Terry Q (Jul 28, 2016)

Every once in a while someone comes along with a “new woodworking design” that has no precedent in existing examples.

I think the reason for that is because whatever you can dream up has already been tried by true craftsmen in centuries past, and they were not able to overcome the limitations of wood movement any more than you can.

The reasons you can’t find a two hundred, or five hundred year old example of a similar table is not because someone didn’t try to build one, it’s because the table didn’t survive.

There is good reason to build something like this on a plywood base with thinner veneers. I think it would make it easier as well. You could lay out the design on plywood and cut the wood strips to fit. You could probably use wood strips up to 5/16 thick and make this work. Two or three layers of plywood building the table thickness, lay out the design, cut the wood and fill the design, then route a smooth round table at the end, putting edge banding around the entire table.


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## woodnthings (Jan 24, 2009)

*Afraid of wood expansion or contraction?*

Just use dry wood!
https://www.youtube.com/watch?time_continue=1&v=cBBPIxjgBuc


:vs_cool:


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## gj13us (Apr 19, 2016)

Go for it. Maybe it'll fail in a couple months, or a few years, or never. Regardless, you'll have gotten a whole lot of experience trying to make all those cuts accurately enough to work.


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## woodnthings (Jan 24, 2009)

*Cutting precise wedges .....*



gj13us said:


> Go for it. Maybe it'll fail in a couple months, or a few years, or never. Regardless, you'll have gotten a whole lot of experience trying to make all those cuts accurately enough to work.



This site has some interesting approaches on cutting precise angles:
http://waterfront-woods.com/Projects/schannotablediscussion.htm
http://www.waterfront-woods.com/Projects/RoundTable/TableBlog.html

Read page 7 Making The Wedges.
This guy made only 8 wedges, and had a great deal of difficulty. He uses a sliding table table saw for the most precise cross cuts:

_After making the first pass on the saw, I laid out all 8 wedges, keeping the first 7 joints tight so the entire error would be visible in the eighth joint. I ended up with a gap at the center of about 1/8 inch. This meant that each cut was off by just 1/128th of an inch over a distance of 30 inches. This meant my first attempt was actually 22.515 degrees, or an error of 0.0149 degrees._

THE ANSWER!
Here's what he says about using solid wood for the wedges:

_ I don't recall if I mentioned this earlier, but *you cannot use solid lumber in a radial pattern such as this table*. As the wedges expand or contract, the angle would change from the perfect 45 degrees. In the winter, the table would have gaps at the outside, and in the summer it would have gaps in the center. This is why I used the high-density maple plywood as the core material._

So, there it issummed up very nicely. I'll admit that I was wrong, but 8 wedges are way different than over 100 or what ever number this design would require. Building it would certainly settle any and all "opinions" on the self destruction theory.


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## AwesomeOpossum74 (Jan 27, 2017)

Same here with seeing designs like this in veneer over stable sub. I don't have any real experience with this type of build, but my gut feeling doesn't give much hope to solid wood. I could just see waking up in the night to a big "craaackk!" and finding a tepee where a table once was.

Why not build a smaller version with fewer wedges (for simplicity) and subject it to different environments over time before embarking on the big project?


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## Wesley75 (Oct 29, 2019)

Hi All (again)
Just wanted to thank everyone for the input.

I came up with a few complicated reasons why this might work, but I think there may be a fairly simple reason why it won't (even with the hole in the center :-( ). I'll post in a couple of days for closure once I've had a little more time to think it over. Guess it's back to the drawing board... 

Regarding the veneer option, I understand this is the reasonable (sane) approach for this type of project, and it can yield some spectacular results... but I'm having trouble giving up the solid wood construction. If I can come up with a redesign that I think will work I'll post it up as well.

All the best, and thanks again!


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## Tool Agnostic (Aug 13, 2017)

Is there a way to build a simple prototype and then run some type of accelerated tests? 

I can imagine a basic prototype design, but am not sure about inducing wood movement. Freezer to oven (on warm) to freezer to oven, perhaps? Can you spray a mist to induce swelling from moisture? Steam it when you take a hot shower?


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