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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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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.
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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Discussion Starter #24
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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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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Discussion Starter #27
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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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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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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Discussion Starter #31
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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Discussion Starter #32
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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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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Discussion Starter #35
MrBentonToYou-

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

One question on this point:

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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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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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.

Thanks in advance,
Ernie
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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