# joining 12/4 red oak for a table top



## ESmithIII (Jan 15, 2011)

Any advice on joining some 12/4 red oak lumber together for a table top? I can use biscuits or dowels, but would like to know what works best. I have never joined anything so thick.

Table will be 80" x 40", and the lumber I have is 12/4 and 10" wide.

Thanks in advance,
Ernie


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## JMC'sLT30 (Oct 26, 2010)

WOW! 3" thick.that's gonna be one heavy table. Make sure you got your MC in the right place or you'll end up like the maple table.
Check this out: http://www.beautifulwood.net/html/breadboard_ends.html


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## Julian the woodnut (Nov 5, 2008)

For something that thick I might try a spline joint just to help line up those thick slabs. With a sline joint you'll need to stay away from the edges so it won't be seen after glue up.


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## cabinetman (Jul 5, 2007)

The MC would be critical for stock that thick and that wide. With that much gluing surface, just glue, cauls, and clamps will be needed. The mating edges should be jointed 90 degrees to the face. Alternate the cross clamps above and below the boards to get even clamping.












 







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## ESmithIII (Jan 15, 2011)

What does MC stand for?


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## ESmithIII (Jan 15, 2011)

ok, disregard. Moisture content. What should it be? This wood has been air drying since hurricaine Katrina.


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## sketel (Sep 15, 2010)

Why not build your table like a door and use stave core with 1/4" face veneers? It would be a lot more stable. If it were quarter-sawn white oak, that would be a different story but air-dried red oak may move on you quite a bit. 

You can make stave core by using finger-jointed pine, rip it to strips then glue it back together so the joints don't line up. 

You could even book match the face veneers and/or sequence them in some interesting way if you want that look since you will be resawing out of just a couple boards.


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## GeorgeC (Jul 30, 2008)

JMC'sLT30 said:


> WOW! 3" thick.that's gonna be one heavy table. Make sure you got your MC in the right place or you'll end up like the maple table.
> Check this out: http://www.beautifulwood.net/html/breadboard_ends.html


 
What is an "MC" and what happened to the maple table?

Those "breadboard ends" sound very complicated. Are they worth the effort?

George


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## cabinetman (Jul 5, 2007)

GeorgeC said:


> What is an "MC" and what happened to the maple table?
> 
> Those "breadboard ends" sound very complicated. Are they worth the effort?
> 
> George



"MC" is percentage of moisture content. The breadboard ends on that table should have been done differently. Ordinarily, if done correctly, they are worth the effort.












 







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## dblodgett (Jan 10, 2009)

*I think this might be the maple table they're referring to*



GeorgeC said:


> What is an "MC" and what happened to the maple table?
> 
> Those "breadboard ends" sound very complicated. Are they worth the effort?
> 
> George


George - I think that they might be referring to my table. You can see what happened here: http://www.woodworkingtalk.com/f2/table-disaster-ideas-22380/ And I'm glad to have learned the proper name of the "end caps" (what I have been calling them). I glued and screwed them all the way across. I thought the wood was dry enough that it wouldn't expand / contract to the level that it did, and the drying basically ripped the table in half. The integrity of the table is okay due to the absurd strength of the substructure (I tend to over-engineer), but I'm REALLY bummed about how it looks now. I might take the easy way out and fill it with something...... Once I figure out the best thing to use...


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## dblodgett (Jan 10, 2009)

BTW - my table was roughly 9/4 when planed and "dried." For what it's worth. I biscuited it every 15 inches or so just to add a bit of torsional strength to the table. I also used pocket-hole screws, but another member (woodnthings) told me I shouldn't have done that because it put uneven pressure on the joing (makes perfect sense ------ in retrospect). But I would definitely biscuit it -- it certainly can't hurt.


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## JMC'sLT30 (Oct 26, 2010)

dblodgett said:


> George - I think that they might be referring to my table. You can see what happened here: http://www.woodworkingtalk.com/f2/table-disaster-ideas-22380/ And I'm glad to have learned the proper name of the "end caps" (what I have been calling them). I glued and screwed them all the way across. I thought the wood was dry enough that it wouldn't expand / contract to the level that it did, and the drying basically ripped the table in half. The integrity of the table is okay due to the absurd strength of the substructure (I tend to over-engineer), but I'm REALLY bummed about how it looks now. I might take the easy way out and fill it with something...... Once I figure out the best thing to use...


Yes I was refering to your table, only because I did'nt have a picture of my 2" thick pine french farm table I built that did exactly the same thing as yours. OUCH:furious: That's when I found out about breadboard ends and their purpose. Oh yeah and moiture content, even though the wood was reclaimed it still moved a lot. I do apoligize if I offended you by using your table for example.


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## dblodgett (Jan 10, 2009)

JMC'sLT30 said:


> Yes I was refering to your table, only because I did'nt have a picture of my 2" thick pine french farm table I built that did exactly the same thing as yours. OUCH:furious: That's when I found out about breadboard ends and their purpose.


Thanks JMC, and the article you posted is fantastic. I've added the link to my favorites. It does seem like a lot of work, and while I didn't originally intend to use breadboard ends, when I was looking at tables online to get design ideas, I realized that the table simply wouldn't look finished without them.


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## dblodgett (Jan 10, 2009)

JMC'sLT30 said:


> Yes I was refering to your table, only because I did'nt have a picture of my 2" thick pine french farm table I built that did exactly the same thing as yours. OUCH:furious: That's when I found out about breadboard ends and their purpose. Oh yeah and moiture content, even though the wood was reclaimed it still moved a lot. I do apoligize if I offended you by using your table for example.


...........and you absolutely DID NOT offend me. I appreciate all of the advice I've received through this forum, and if we can't learn from each other's mistakes and successes, what's the point! I'll see if I can't drum up a few more mistakes that people can learn from. Like a poster I saw one time of the rusted hull of an old ship half sunk in sand:
"It may be that your sole purpose in life is simply to serve as a warning to others"

I love that poster


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## mrbentontoyou (Aug 3, 2010)

If ALL of the oak for this table top has been air drying for around 5 years, and it was stickered and stacked properly (dead level, equaly spaced and sized stickers, weighted on top or ratchet strapped tight, covered with a roof and shaded from direct sunlight) than whatever the MC is it should be consistent throughout all the boards which to my mind is more important than the actual number. 

If you don't have a moisture meter you should get one; decent ones start around $120 and it is cheap insurance. I use a lingo mini d and it works great, cheap on amazon. if you are about to spend your time wrestling 12/4 x10" oak boards you want to know the table is going to have a good chance at staying flat!

If you have or get a meter, your boards should be around 12% MC, give or take a point or two for your location (your area's relative humidity). 

if the MC is good and the boards came off the stack nice and flat, you should be good to go by just edge jointing accurately and glueing up. You want to get this right the first time so check your edges with a reliable square at a few points along the length and make sure you are at exactly 90º.

cauls across the width will help keep you flat during glue up. you could make some curved cauls, which i find useful for big table top glue ups. If you search the interweb you will find advice on making those. 

Biscuits will not add any strength to the top but will help line the boards up and keep everything together during glue up. If you have a biscuit jointer you may as well pop a few #20's in there just to keep everything aligned. 

You may want to glue the top up in two stages. join two boards at a time, then join the two glue ups together. That way you are only working with one glue line at a time and you can really focus on a perfect joint. :thumbsup:

out of curiosity, what is the base design for this beast?


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## ESmithIII (Jan 15, 2011)

MrBent- 

Thanks for the informative reply. I will post the design as soon as my boss (read wife) approves the final design.

In terms of the curved cauls, I tried to search for them without luck. I am having trouble picturing it. Could you post a link?

Thanks again in advance.


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## sketel (Sep 15, 2010)

If you run your boards on the jointer, you just need to be sure to flip the boards so that any slight variation from 90 will be compensated for. Flipping the boards insures you will be exactly flat if you clamp it right.

Don't know if that makes sense, just think about it this way: you could be out of square a full 5 degrees on all your edges but if you flip the boards so that one board has a positive bevel and the next has a negative bevel, you will be able to stay exactly flat across the full width.


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## Bear Creek (Jan 15, 2011)

Unless you want a table that thick and heavy why don't you resaw the red oak to 1.5" or so. It would reduce the weight of the table significantly and you would have material left over for something else. It would also make it easier to construct the table. If you want the look of a thick table you can get the thickness with the aprons, assuming you have aprons. Just a suggestion, good luck.


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## ESmithIII (Jan 15, 2011)

My initial plan was to have a thinner top, but the lumber I was able to get was 3" thick. I will plane it to 10/4, but that is still very thick. I do not have the means to resaw it, unless someone can recommend someone here near Hattiesburg, Mississippi that I could pay to do it.

I have a good jointer, and will follow your suggestions about alternating faces so that if it is not perfectly 90 degrees they will still match up.

I have a question on the breadboard ends: how much should I enlongate the holes in the tenon? Also, I assume that the elongation should allow the table to grow or shrink in width, not length?

Thanks in advance for helping a newbie.


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## mrbentontoyou (Aug 3, 2010)

ESmithIII said:


> In terms of the curved cauls, I tried to search for them without luck. I am having trouble picturing it. Could you post a link?
> 
> Thanks again in advance.


curved cauls are sold commercially as a "bowclamp", but something similar can be made in the shop easily. mine are made from 3"x3" oak and maple (salvaged from pallets), about 38" - 42" long. 
begin by squaring up your stock. i introduce a slight curve to one edge with a jack plane. I start about 3" from the end, planing towards that end, and with each stroke I move back a little till i get to the middle. do the same on the other side. the result is that the ends of the caul wind up around 1/16" to 1/8" lower than the middle. experiment to get the right amount of curve. I label the curved side with a marker and cover it in clear packing tape so glue doesn't stick. when clamping a panel or table top, place the cauls' curved side against the work, running across the glue up. one clamp at each end pulls the curved edge straight, which applies pressure in the middle.


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## JMC'sLT30 (Oct 26, 2010)

Daren has put together a list of sawyers (probably some in your area). As far as the tenon on the breadboard you might check the specs on any expansion expectation of red oak and make your determination from that.


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## mrbentontoyou (Aug 3, 2010)

ESmithIII said:


> My initial plan was to have a thinner top, but the lumber I was able to get was 3" thick. I will plane it to 10/4, but that is still very thick. I do not have the means to resaw it, unless someone can recommend someone here near Hattiesburg, Mississippi that I could pay to do it.
> 
> 
> I have a question on the breadboard ends: how much should I enlongate the holes in the tenon? Also, I assume that the elongation should allow the table to grow or shrink in width, not length?


Most tables you see are between 3/4" and 1-1/4" thick. I personally think big, massive tops look great and stand out. I've done a few tables with 2" - 3" thick tops in maple, walnut and fir and they really make a statement when viewed next to a regular table. my 2¢. 

my other 2¢ is that if an 80" by 40" glued up panel of solid wood is going to want to warp or cup or move in any way, it is going to do just that despite any type of bread board end caps. wood movement is a force of nature. best to start with stable material. but for looks, i do like bread boards in certain applications. 

(again, just my opinions, take 'em for what they're worth)

as for enlongated bread board pin holes.... 
you are correct that the wood will not move along it's length, just it's width (it will get slightly thicker and thinner too but not enough movement there to worry about).

the rule of thumb for movement across the width is generally 1/8" per 12" of width. _generally_. Let's say you locate a fixed, glued pin at the center of the 40" bread board, and want to locate another pin 4" in from the edge of the top. that gives you 16" of wood movement to account for. I would consider giving that pin at least 3/16" of wiggle room. 

the guessing game comes into play when you try to figure out where the wood is in it's movement cycle when you put the table together. if you are allowing 3/16" of movment and the wood is in the middle of it's expansion/contraction, you can plan on centering a pin and leaving it 3/32" on each side to move. 

but if you are building in the winter and you are assuming the wood is at it's "smallest", you may want to locate the pin so the bulk of the wiggle room is on the side of the pin that will allow growth.

I will admit to sometimes over thinking things. I guess you could also just give the pin 1/2" in either direction and sleep soundly at night. :laughing:


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## <*(((>< (Feb 24, 2010)

ESmithIII said:


> My initial plan was to have a thinner top, but the lumber I was able to get was 3" thick. I will plane it to 10/4, but that is still very thick. I do not have the means to resaw it, unless someone can recommend someone here near Hattiesburg, Mississippi that I could pay to do it.
> 
> I have a good jointer, and will follow your suggestions about alternating faces so that if it is not perfectly 90 degrees they will still match up.
> 
> ...


I think you mean mortise, I'm wondering the same for future reference.

Nevermind there is a page two to this discussion.


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## ESmithIII (Jan 15, 2011)

ok, someone is going to have to explain how to use my moisture meter. Does it matter where I take the reading? Pins parallel to the grain or perpendicular? I get a lot of variation, from 7% to 11%, and an even lower reading when inserting the pins into the end grain.


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## mrbentontoyou (Aug 3, 2010)

the ends will read lower because that is where moisture exchange happens fastest. don't bother checking the ends. 

the middle of the faces (at the center of the thickness) will probably read higher because that is the area that sheds moisture slowest. this is generally where you want to keep a watch on MC.

to my knowledge, pins parallel or perpendicular doesn't mater, just as long as they are buried to the hilt. (someone else may have a definitive answer on that)

fish around with different boards, see if they are all uniform, and reading about he same.

compare measurements taken from all your boards from the same area, say center of each face. if 11% is your highest reading and is consistant among all your boards you may be in good shape.

are the boards indoors or outdoors right now?


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## ESmithIII (Jan 15, 2011)

They are in my garage at this point where it is about 60F.

I have planed them to 10/4, and will be running them through the jointer this week.

I found a fascinating white paper on moisture content and its effect on wood.

http://www.extension.purdue.edu/extmedia/FNR/FNR-163.pdf


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## ESmithIII (Jan 15, 2011)

JMC'sLT30 said:


> Daren has put together a list of sawyers (probably some in your area). As far as the tenon on the breadboard you might check the specs on any expansion expectation of red oak and make your determination from that.


JMC- Where can I find this list? I searched the forums under "sawyers" to no avail.

Thanks in advance,
E


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## Allen Tomaszek (Dec 11, 2010)

Good luck on your project. It sounds pretty cool. Large table tops are kind of like book collections. They're pretty impressive when you're putting them together but they really are a pain to move. 80x40 table op at 10/4 will weigh in at about 200lbs just for the top. Add in the over engineered support and you're up to???

Not that it should discourage you but it might be a consideration in your design. Will your finished table easily disassemble if you ever want to move it more than a few feet?


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## JMC'sLT30 (Oct 26, 2010)

Try looking here http://nelsonwoodworks.biz/pb/wp_a9976cb4/wp_a9976cb4.html
Good luck
James


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## mrbentontoyou (Aug 3, 2010)

*opinion alert!*

who cares if a dining table is heavy? 
how often does one need to move a dining table?

what you must do just about every day is look at it, sit at it, use it. 
it may as well be something that puts a smile on your face during these daily activities, even if you have to tip the movers with some extra beer money when/if the time comes to change address. 

i'm milling wood now for a table that will be 11'x42" with a top as close to 3" thick as i can get it (milling 14/4 boards for the top, we'll see how they finish out). the trestle leg assemblies will finish around 5" thick. it will be massive and ridiculously heavy. i am not looking forward to humping thick 11'+ boards around my shop during the making of this piece, especially since there will be two of them each 21" wide. but i am looking forward to the finished product, which will be uniquely massive, and unlike the vast majority of tables out there. the client who commissioned this piece is also excited about the visual impact and exclusive proportions. 

so i guess it's a matter of priorities. 
if the thought of a certain dimension strikes a fancy, go for it. :thumbsup:
you'll enjoy it way more than you'll curse it. 

that's my opinion anyway, and i'm sticking to it!


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## ESmithIII (Jan 15, 2011)

*Diagram of table*

Here is the "approved Design" for the table.


Oak Table by esmithiii2003, on Flickr

Please be critical if you have any concerns with the design. I am looking for input because I want this thing to look great when it is done.

The top will be removeable from the frame. it will be loosely attached to the base using L shaped brackets that will allow the top to expand and contract without pulling apart.


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## ESmithIII (Jan 15, 2011)

oh, if anyone would like the 3D model (using Google Sketchup) let me know and I will e-mail it to you. I do not know how to post it on-line.

Thanks,
Ernie


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## ESmithIII (Jan 15, 2011)

*Sketchup Model*

ok, I figured out how to attach it... (I think!)


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## mrbentontoyou (Aug 3, 2010)

looks pretty good so far, big and solid that's for sure. 

two things that would bother me:

i'd be really apt to strike those lower stretchers for the sake of leg room. you can squeeze 3 people on each side with the spacing you have but whoever sits at the ends is in for an uncomfortable dinner. 

second, i would situate the legs so they were directly supporting the main table top and not the breadboards. 

at 31.5" it will feel a little tallish unless you are used to that height but even so you will get used to it soon enough, and it's better than having cramped knee room below those top stretchers/aprons.


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## ESmithIII (Jan 15, 2011)

MrBentonToYou-

Thanks for the advice. Sounds like good advice to me.

One question on this point:



mrbentontoyou said:


> I would situate the legs so they were directly supporting the main table top and not the breadboards.


What is the concern with the support being on part of the breadboards? I am concerned about the stress breaking the tenon in the main table if kids climb on them.

Thanks again,
Ernie


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## mrbentontoyou (Aug 3, 2010)

ESmithIII said:


> What is the concern with the support being on part of the breadboards? I am concerned about the stress breaking the tenon in the main table if kids climb on them.
> 
> Thanks again,
> Ernie


i have honestly never read or heard exactly why a top can or can't be supported by its breadboard ends and i've never done it and seen it fail so i'm giving you my gut feeling on why it seems wrong to me:

it seems like climbing kids would put a similar sort of stress on the breadboards as the weight of the top will. breadboards are a decorative element to cover end grain and some people claim they help panels stay flat but if they are attached properly (made fast at the center with allowance for movement at the ends) they are not a structural part of the top and aren't designed to bear weight, either statically as in supporting the top by the ends, or intermittently as in supporting energetic kids. 

ps-
speaking of heavy furniture- going monday to finish milling big slabs for a very large dining table and some fireplace mantels. i'll post up some photos and maybe video of the process in the milling/forestry forum, hopefully monday or tuesday night.


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## firemedic (Dec 26, 2010)

ESmithIII said:


> Any advice on joining some 12/4 red oak lumber together for a table top? I can use biscuits or dowels, but would like to know what works best. I have never joined anything so thick.
> 
> Table will be 80" x 40", and the lumber I have is 12/4 and 10" wide.
> 
> ...


You could just edge glue it... But I preffer a full length spline for my tables. I haven't built any with tops that thick, but many have been 8/4 and splints work great.

I actualy really like gorrila glue for splines, the expansion and bind seems to help reduce minor wood movement.

Since katrina, huh? Where did it fall? all I lucked up with was a bunch of ancient almost useless cedar that fell on around the plantation...


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