Breadboard Ends Help - Page 2 - Woodworking Talk - Woodworkers Forum
 20Likes
Reply
 
Thread Tools Display Modes
post #21 of 29 Old 01-12-2019, 08:42 PM
Former Member
 
Join Date: Nov 2012
Posts: 1,512
View 35015's Photo Album My Photos
Quote:
Originally Posted by BrosephMansby View Post
Im doing loose tenons which will prevent cupping.
I'm pretty sure that "loose tenon" (aka toggle tenon or free tenon) have little to no bearing on whether a solid build up diaphragm of wood (aka table top) is going to have any "cupping" or not.

The Bread Board if it is mounted correctly...that is what will arrest cupping at the end of the diaphragm of wood.

If the individual boards are free tenoned and spline to one another this can greatly inhibit (almost stop completely) any cupping, warp, twist at all from taking place within the field of the table itself. This means that there is a free tenon ever 5" to 10" down the length of both sides of the boards/planks (variable to wood thickness and table size these numbers can all go up or down accordingly) and their depth into these can very from all the way through to no less than 2" into plank. This can also be achieve by sliding dovetail and tapperd splines on the bottom of the table too or in addition to the free tenon...

In the picture below:
So I will gather that the middle pin/peg is fixed...???...and the others have the slot cut in them that go into the bread board...Did you take a photo of how large a slot you used?

Last edited by 35015; 01-12-2019 at 08:45 PM.
35015 is offline  
Sponsored Links
Advertisement
 
post #22 of 29 Old 01-12-2019, 09:05 PM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 27,573
View woodnthings's Photo Album My Photos
All this time I thought a diaphragm was ....

I thought it was a birth control device among other things, but never knew it was a structural term:
https://en.wikipedia.org/wiki/Diaphr...uctural_system)


Me thinks there's a diaphragm in my toilet flusher, my Holley carburetor accelerator pump and somewhere inside my chest cavity .... who knew?

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is offline  
post #23 of 29 Old 01-12-2019, 09:12 PM
Former Member
 
Join Date: Nov 2012
Posts: 1,512
View 35015's Photo Album My Photos
Working with PE too much...

That made me laugh...Thanks...

Moment connections, load in shear and structural diaphragms within roof, wall and related "diaphragms" are bantered about all the time with the projects we do... It just becomes a habit after time. Anything that creates a large field out of smaller parts or materials then becomes a diaphragm whether structural or otherwise...or field...or...just the "table top" which would be better if I could break some of my literary habits...LMAO...
35015 is offline  
Sponsored Links
Advertisement
 
post #24 of 29 Old 01-12-2019, 09:43 PM Thread Starter
Junior Member
 
Join Date: Jul 2017
Posts: 20
View BrosephMansby's Photo Album My Photos
Yeah, the center tenon is fixed and the others have room to move laterally. Tenons are 4in wide .75in thick.
35015 likes this.

Last edited by BrosephMansby; 01-12-2019 at 09:50 PM.
BrosephMansby is offline  
post #25 of 29 Old 01-12-2019, 09:50 PM Thread Starter
Junior Member
 
Join Date: Jul 2017
Posts: 20
View BrosephMansby's Photo Album My Photos
Yeah your right the breadboard and tenon keeps the table top flat.

Last edited by BrosephMansby; 01-12-2019 at 09:56 PM.
BrosephMansby is offline  
post #26 of 29 Old 01-13-2019, 11:23 AM
Senior Member
 
Join Date: Sep 2011
Posts: 26,046
View Steve Neul's Photo Album My Photos
There are other ways to keep a table top flat that don't have the problems the breadboard has. The breadboard end since it's not completely glued on is easily broken loose and then needs repair. Then over time the top shrinks and the breadboard end stick out past the top on each end.

If you are building a table the top that is fastened to the table if you put a board flat under the top behind the skirt with elongated screw holes it will allow for the wood movement and be out of sight. Also the underside of the table should be finished. This is something that is seldom done and a moisture imbalance from one side to the other is the leading cause of a table top warping. By not finishing the underside it allows moisture from the air to make the underside swell causing it to warp. By sealing both sides the moisture content is more likely to stay the same on both sides.
Steve Neul is offline  
post #27 of 29 Old 01-13-2019, 11:46 AM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 27,573
View woodnthings's Photo Album My Photos
How to stop cupping, other ways than a breadboard

Quote:
Originally Posted by Jay C. White Cloud View Post
.......



If the individual boards are free tenoned and spline(d) to one another this can greatly inhibit (almost stop completely) any cupping, warp, twist at all from taking place within the field of the table itself. This means that there is a free tenon ever(y) 5" to 10" down the length of both sides of the boards/planks (variable to wood thickness and table size these numbers can all go up or down accordingly) and their depth into these can very from all the way through to no less than 2" into plank. This can also be achieve(d) by sliding dovetail and tapered splines on the bottom of the table too or in addition to the free tenon...

This approach is one I've not seen before, but it may make a good case for biscuits, dowels, Dominos and loose tenons. I see how it would work by restraining the edges of the planks from moving by connecting it mechanically to the adjoining plank.



I'd like to see this done and tested over time. Wider planks are always more prone to cupping and are often ripped in 2 and reglued to maintain the grain pattern.

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)
woodnthings is offline  
post #28 of 29 Old 01-13-2019, 04:07 PM
Former Member
 
Join Date: Nov 2012
Posts: 1,512
View 35015's Photo Album My Photos
Quote:
Originally Posted by Steve Neul View Post
...There are other ways to keep a table top flat that don't have the problems the breadboard has...
I can't speak to someone else's experience with this family of joinery...to be sure!

It could be poorly done examples and/or some other abuse, event unknown to have such deleterious effects, or issue at play from just poor design application...

What I can attest to is that even without glue, traditional fixed tenon and/or free tenon joinery systems within breadboards (and related applications) when designed and facilitated properly have no issues whatsoever over time with becoming "broken loose." This has been true for the countless historical examples I have examined, nor in the modern interpretations that you could literally..."hang a truck from"...again without adhesives in many of these iterations...

I could not agree more that the failure to finish appropriately both sides of a table is often a formula for disaster...especially for the less robustly jointed examples I see going together today...
Tennessee Tim likes this.
35015 is offline  
post #29 of 29 Old 01-13-2019, 04:08 PM
Former Member
 
Join Date: Nov 2012
Posts: 1,512
View 35015's Photo Album My Photos
Quote:
Originally Posted by woodnthings View Post
This approach is one I've not seen before, but it may make a good case for biscuits, dowels, Dominos and loose tenons. I see how it would work by restraining the edges of the planks from moving by connecting it mechanically to the adjoining plank...I'd like to see this done and tested over time. Wider planks are always more prone to cupping and are often ripped in 2 and reglued to maintain the grain pattern.
Hi Woodnthings,

The biscuits just don't have the "meat" to work well, or be applicable structurally...

As for "testing over time," that has already been done in many examples both historical and contemporary applications. Dowels and loose tenon (what a Domino is today) when sized appropriately are well proven over centuries of applied relevance in floors, covered bridges, ship hauls, and related practiced implementation of this form of structural joinery. This is true to the point that structural roof/floor diaphragms are part of PE sign offs on projects all the time now, with just one example being the floors/walls of wooden skyscrapers where this exact application is employed routinely...but of course in a modern context.

The timber fame I designed in Wisconsin for the public Farmers Market in Menomonie employees loose toggle tenon (aka Domino) in the roof corbel assemblies to the rafter plate. These take on massive loads during wind and snow events. Being a public space, the engineering scrutiny such joinery gets, from not only the PE I work with, but also state PE is arduous and intense to say the least. They would not ever sign off on anything that wasn't tested...and/or...well proven within the historic vernacular...

If you go back through some of my posts, I have shared links, photos, and videos of examples of these...
Tennessee Tim likes this.
35015 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Tight tenon location for breadboard sides? Unsoluble Design & Plans 6 07-10-2018 03:38 PM
Breadboard ends - drawbore or no? BZawat Joinery 2 03-23-2016 11:37 AM
Breadboard ends origin WesTex General Woodworking Discussion 3 03-16-2016 06:56 PM
Dining table build - breadboard questions DeanK General Woodworking Discussion 7 11-02-2015 09:41 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome