# Large table. concerns for expansion and contraction



## needshave (Jan 13, 2013)

I have many years of woodworking experience under my belt, but primarily in the replication of historic moulding and features of historic properties that we restore. I have built a few large ornate bars but the width of the bar typically does not exceed 24" and without bread boards.

Now I want to build a large Oak farm table, with width approaching 48" and breadboards. I'm concerned about the expansion and contraction both the table top and the bread board will see. I will most likely make the top of 8/4 rift cut Oak, with a 10" bread board. the table will be 96" long. The boards making up the top will probably be either dowed or more likely put together with loose tenons. The bread board will most likely be the same, but thats where the concerns lie, I know the opposing or opposite direction of the grain will expand and contract differently than the table top. And suggestions from experience you might be able to share? I appreciate your thoughts.


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## jerryminer (Jun 15, 2014)

No need for dowels or tenons in the long-grain glue-up, unless you want them for alignment. Modern glues will adhere well-made long-grain joints better than the internal adhesion of the wood itself.

Traditional breadboard ends allow for expansion with slotted holes and no glue, except for the very center:


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## wormil (Nov 19, 2011)

48" is very wide for a table, makes conversation and passing more difficult.


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## needshave (Jan 13, 2013)

Thanks Jerryminer for addressing the question. Your comment does help!


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## WhyMe (Feb 15, 2014)

Just glue up of the top panel by flat butting the edges. Joint the edges square and flat for a good bond. A 10" bread board end is quite wide, but don't solid glue it to the end of the panel. The panel needs to float inside the bread board end so not to split. Only use glue on the center few inches to the panel and peg the ends as shown in jerryminer's post. Leave plenty of room in bread board ends for movement of the top.

Here's a farm table I made using bread board ends. http://lumberjocks.com/projects/300306


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## rwe2156 (May 7, 2014)

Are you referring to the breadboard moving? Keep the bread board pins closer to the seam be sure the tenons extend at least 1/2 way into the bb.

That is an extremely wide bb. You will need 5" deep tenons or if the apron is supporting at least to within 3" of the edge you could get by with 3" tenons. If this is a trestle table or the bb is unsupported, I wouldn't make it more than 5" wide.


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## needshave (Jan 13, 2013)

Why Me…: thanks so much for your comment and link. It was a big help. This table needs to be oak as well and your table turned out beautifully. The details on your bread board help a great deal. In regard to the table top glue up, I was somewhat concerned about table top cupping, I was going to mortise and tenon the joints to provide additional protection from cupping and strength. You don't feel necessary.


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## needshave (Jan 13, 2013)

rwe2156….. Yes. I'm concerned about the moving of the breadboard. So let me see if I understand fully what you're saying. Let say the tenons are 5" long, you're saying rather than pin at 2.5" from the seam, locate the pins closer to the seam say 1.5" ? Is that correct? Yes the BB is quite wide. The table is a duplicate of an existing table left in a building that I purchased. The building dates 1896 and the table appears to be close to that vintage. The bread board is supported by 4 out riggers that are supported and mounted to the apron. They support the BB, but are not attached to it.

Thanks again for your comments.


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## WhyMe (Feb 15, 2014)

To reduce cupping of the top flip the boards so the end grain alternates.


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## needshave (Jan 13, 2013)

Yes, Agreed. I certainly plan to do that. What are you using for glue? Is there an Accepted standard most use her on LJ? I have been using Franklin Titebond !!.


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## Tony_S (Dec 16, 2009)

> Are you referring to the breadboard moving? Keep the bread board pins closer to the seam be sure the tenons extend at least 1/2 way into the bb.
> 
> That is an extremely wide bb. You will need 5" deep tenons or if the apron is supporting at least to within 3" of the edge you could get by with 3" tenons. If this is a trestle table or the bb is unsupported, I wouldn t make it more than 5" wide.
> - rwe2156


This…100%
I'd also suggest drawboring the pins.
eg. http://www.thewoodwhisperer.com/videos/drawbored-mortise-tenon/


> To reduce cupping of the top flip the boards so the end grain alternates.
> - WhyMe


Again…100%


> Yes, Agreed. I certainly plan to do that. What are you using for glue? Is there an Accepted standard most use her on LJ? I have been using Franklin Titebond !!.
> - needshave


The standard here (if there is one) would be Titebond 3, although most wouldn't be able to tell you why the use it, other than it works?
There's no real advantage to TB3 on an interior project other than a longer open time. On the other hand, depending on your experience level, and efficiency during a large scale glue up, a longer open time might be an advantage for you.
Other than that, any yellow PVA will do. The only obvious difference between brand names is open, and set times. Most of which are similar.


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## wormil (Nov 19, 2011)

> To reduce cupping of the top flip the boards so the end grain alternates.
> 
> - WhyMe


This is a myth, there is no truth in it, and it's been debunked many times for decades. Honestly I have no idea who started that myth or why it keeps getting repeated.


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## DirtyMike (Dec 6, 2015)

> To reduce cupping of the top flip the boards so the end grain alternates.
> 
> - WhyMe
> 
> ...


Can you elaborate more on this rick?


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## wormil (Nov 19, 2011)

> Can you elaborate more on this rick?
> - DirtyMike


I was coming back to re-write my post and make it less - confrontational, but too late, oh well.

First, alternating boards isn't going to prevent any one board from cupping. A flat sawn board will naturally want to cup toward the bark side, or as they say "flatten the smile". But if the board is subjected to rapid moisture loss or gain on one side, the wood will expand or shrink on that side and cup accordingly regardless of 'bark side'. Second, the claim is usually that alternating the grain will create a washboard top instead of the entire top cupping the same direction. But that's only true if all boards cup. And IF that did happen, it would still be undesirable because fixing a washboard top means planing down the top and bottom and refinishing. Whereas if the top cups all in the same direction, fixing is relatively easy by kerfing the bottom, refinishing, and reattaching the top (which I have done). I've arranged the grain for best appearance and ease of planing on my tables and it had no influence on cupping.

Once I went back through all my woodworking texts to see if I could find an origin for this idea of alternating grain and it wasn't in any of them so I don't know where it got started. Regardless, even if it were, I find no truth in it and even if it were true, the result is undesirable.


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## DirtyMike (Dec 6, 2015)

nailed it, thanks rick


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## WhyMe (Feb 15, 2014)

Cupping was the wrong term and I was not referring to doing the flip to control it in one board. I was suggesting flipping the boards to minimize bowing of the overall top. I've made plenty of tops and I do find an advantage of alternating the grain to help with controlling overall bowing.


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## needshave (Jan 13, 2013)

I agree with "Why Me". I'm sure I read that alternating grain in a glue up is the proven way to control cupping in my college txt "Woodworking for Industry" but with all the years past, I have not been able to find the text book.

I did find an interesting article by the Wood Whisper on the same subject. Here is the Link

http://www.thewoodwhisperer.com/articles/avoiding-cupped-panels/


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## wormil (Nov 19, 2011)

> I agree with "Why Me". I m sure I read that alternating grain in a glue up is the proven way to control cupping in my college txt "Woodworking for Industry" but with all the years past, I have not been able to find the text book.
> 
> - needshave


You agree it prevents cupping or that it prevents bowing?

So what if you alternate the grain and only one board cups? What if you alternate the grain and the 2 outside boards cup? What does your book say about that?


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## WhyMe (Feb 15, 2014)

> So what if you alternate the grain and only one board cups? What if you alternate the grain and the 2 outside boards cup? What does your book say about that?
> 
> - Rick M


 Don't be so defensive because someone has a different opinion. This is not a "I know better than you do" contest.


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## Tony_S (Dec 16, 2009)

> This is a myth, there is no truth in it, and it s been debunked many times for decades. Honestly I have no idea who started that myth or why it keeps getting repeated.
> - Rick M


It's the way I was taught in school, and during my apprenticeship 30 years ago, and it's the way I teach. I've done panel glue ups small in size, huge in size, in every shape and description. Hell…I have no idea how many. 8-10 thousand in those thirty years?
It's been working out pretty good so far. I honestly can't recall any washboard issues/complaints.

One thing I'll say, I'm in a pretty harsh climate(seasonally) that doesn't always agree with solid wood construction. The average size of each piece, in say a 1" thick finished product, is limited to no more than 4-5" max. That width can go up proportionally in relation to the final thickness. 
The very odd time there is a callback from a client, it's due to cracking, and that's almost always due to poor climate control in the home. 
Would I have washboard issues if I used wider boards in the finished product? Not much doubt I would, but I'd rather sacrifice the grand width of a board a bit, alternate growth rings, and not have any issues at all, overall cupping or washboarding.
Either defect for me would be very costly. Not quite as simple as removing a tabletop and kerfing it or resanding it.


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## wormil (Nov 19, 2011)

Why me, If you want to have a grown up conversation, then do that by answering me instead of trying to twist this into something personal. How wood moves isn't an opinion. If you believe alternating the grain prevents cup, or bow, or whatever, then explain why beyond maybe you read it somewhere. I'm not being defensive, I'm trying to draw you into a conversation so you can understand why it's a myth.


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## wormil (Nov 19, 2011)

Tony, just because you've done it that way doesn't make a fact out of a myth. Same to you, if you believe it then you should be able to explain why it works using what we know is true of wood movement. I outlined my logic, your turn.

edit: 


> I honestly can t recall any washboard issues/complaints.
> - Tony_S


I think you have become confused, the washboard claim isn't mine, it's the basis of the myth-that a tabletop will washboard instead of cup. So if you aren't getting any washboarding, that's a point for me. Ripping them into narrow strips is more advantageous than alternating grain, it makes a more stable but less attractive top.


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## WhyMe (Feb 15, 2014)

> Why me, If you want to have a grown up conversation, then do that by answering me instead of trying to twist this into something personal. How wood moves isn t an opinion. If you believe alternating the grain prevents cup, or bow, or whatever, then explain why beyond maybe you read it somewhere. I m not being defensive, I m trying to draw you into a conversation so you can understand why it s a myth.
> 
> - Rick M


I know it helps counteract bowing of wide panels from actual experience of wood working for almost 40 years. So I don't see it as a myth.


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## wormil (Nov 19, 2011)

How does it counteract "bowing of wide panels?" And do you mean bowing, or cupping? Explain the mechanism. Like I told Tony, believing something doesn't make it true. I don't take anyone's word on anything, especially strangers on the internet and especially when it runs counter to what I know is true.


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## WhyMe (Feb 15, 2014)

> How does it counteract "bowing of wide panels?" And do you mean bowing, or cupping? Explain the mechanism. Like I told Tony, believing something doesn t make it true. I don t take anyone s word on anything, especially strangers on the internet and especially when it runs counter to what I know is true.
> 
> - Rick M


 There are plenty of references on the web that recommend alternating the grain to help prevent warping of wide glued up panels and why. Why should you be taken as all knowing and correct. You are just a stranger on the net.


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## Tony_S (Dec 16, 2009)

> Like I told Tony, believing something doesn t make it true. I don t take anyone s word on anything, especially strangers on the internet and especially when it runs counter to what I know is true.
> 
> - Rick M


Ain't no winning this one.
I'm out.


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## wormil (Nov 19, 2011)

> I m out.
> - Tony_S


I didn't ask anything of you, that wasn't asked of me and I provided it.


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## oldnovice (Mar 7, 2009)

*WOW*, some people can't even have an educated opinion before someone takes it personally!

From what I read, there are two different things being *argued* here and both may have different answers.
I am not bout to say who is wrong or who is right but let's not make it personal!


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## needshave (Jan 13, 2013)

old novice, Your right. It was a friendly discussion that became very personal, defensive and confrontational.

I noticed at least one comment was later "edited", so your not seeing it all. Unfortunately many, including myself, just don't want to participate in a discussion when this type of bullying activity takes place and simply refuse to respond.


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## WhyMe (Feb 15, 2014)

needshave, I apologize. I helped to fuel the fire. I sometimes read things the wrong way and make judgements based on how I perceive a written comment. In other words I may have read an intent in a comment that wasn't there. I hope my comments weren't taken as bullying.


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## needshave (Jan 13, 2013)

Why Me…...NO! I did not think that then nor do I think it now. There is no reason to apologize. Certainly I appreciate your comments and thoughts. it was unfortunate we were not able to continue the discussion.


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## WhyMe (Feb 15, 2014)

With all of that behind us, I wish you the best with getting your table built. Let us see your progress and finished results. Also using rift cut oat if properly dried should be very stable.


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## needshave (Jan 13, 2013)

Thanks Why Me. I have a good source of kiln dried oak here and we normally allow it to set a bit before starting a project so all should be good.

In all honesty, yesterday's post makes one reluctant to post much in the future on LJ.

Regards.


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## WhyMe (Feb 15, 2014)

> Thanks Why Me. I have a good source of kiln dried oak here and we normally allow it to set a bit before starting a project so all should be good.
> 
> In all honesty, yesterday s post makes one reluctant to post much in the future on LJ.
> 
> ...


That can happen in any forum about any topic. But I think it's rare on LJ, so don't let it stop you from asking future questions.


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## wormil (Nov 19, 2011)

> ...when this type of bullying activity takes place and simply refuse to respond.
> - needshave


Since you let WhyMe off the hook and won't respond to me, I have to assume you are calling me a bully. It would be decent if you step up and address me directly. I did not bully anyone. I did not make it personal and in fact I steered it back on topic when another poster tried to make it personal. What I did was step on a myth that keeps getting revived. I was asked to elaborate and I gave a technical explanation of why it's a myth. When the 2 people pushing this idea were challenged to give a technical explanation of why, they could not. There isn't anything else to it. They got upset, I didn't. Your question, which wasn't very specific, was answered several times over. What I said, I said for the benefit of anyone reading that may have an incomplete understanding of how wood moves; who may have been told this alternating grain theory and accepted it without question. In the end, doing it isn't going to hurt anything but isn't necessary either. Best of luck with your table.


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## jerryminer (Jun 15, 2014)

Rick, you seem to be unaware that your style often comes across as confrontational and insulting.

Example:



> If you want to have a grown up conversation, then do that by answering me…- Rick M


Implying that someone is not "grown up" is a personal insult. No need for it here. (You may not have intended to be confrontational, but your posts can read that way)

The "alternating grain" issue is an interesting one that will probably not be settled any time soon. I happen to be in the "best-looking face up" camp, but I recognize that there are other views on this issue.

I hope we can all discuss this and other issues without resorting to insulting each other. Happy woodworking to everyone!


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## wormil (Nov 19, 2011)

You don't have to like me, I don't have to like you. You say I was insulting but that happened in response to WhyMe going off topic and posting about me instead of about the subject. So how about we stop making it about me and stay on point, fair enough?

And yes, I was aware it came off as confrontational. My patience runs thin when people give bad advice. This time it was quoted before I had a chance to tone it down. 


> I was coming back to re-write my post and make it less - confrontational, but too late, oh well.
> 
> First, alternating boards isn t going to prevent any one board from cupping. A flat sawn board will naturally want to cup toward the bark side, or as they say "flatten the smile". But if the board is subjected to rapid moisture loss or gain on one side, the wood will expand or shrink on that side and cup accordingly regardless of bark side . Second, the claim is usually that alternating the grain will create a washboard top instead of the entire top cupping the same direction. But that s only true if all boards cup. And IF that did happen, it would still be undesirable because fixing a washboard top means planing down the top and bottom and refinishing. Whereas if the top cups all in the same direction, fixing is relatively easy by kerfing the bottom, refinishing, and reattaching the top (which I have done). I ve arranged the grain for best appearance and ease of planing on my tables and it had no influence on cupping.
> 
> ...


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## jerryminer (Jun 15, 2014)

> You don t have to like me, I don t have to like you….- Rick M


I'm not asking you to like me. I'm asking you to keep the conversation civil.


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## WhyMe (Feb 15, 2014)

> So what if you alternate the grain and only one board cups? What if you alternate the grain and the 2 outside boards cup? What does your book say about that?
> 
> - Rick M
> 
> ...


 Rick, since I keep getting mentioned as being let off the hook I want to apologize you too for assuming you were getting defensive and that I took us off topic.


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## wormil (Nov 19, 2011)

You have my thoughts on the subject. I'm bowing out. If anyone would like to discuss wood movement, PM me.


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