So I'm in the middle of making an end table from a design in WOOD magazine. I've decided to use some really wide boards for the top (which is why I've been experimenting with a planer sled). Now, conventional wisdom these days is to take six inch boards, and then glue them up, with the belief that they'll be much more stable. I remember asking this question of Kelly Mehler, a guy who's written a great book called The Table Saw. I asked him about this, and he said it was all hogwash. I followed up with another question, saying what if you're talking about air dried wood, which is what I'm working with. He said it didn't matter, and in fact, he only uses air dried wood for his projects. His attitude was that he wanted to use the biggest boards he could find, because he saw incredible beauty in them.
Anyway...that's a long way to get to my question. For those of you more experienced woodworkers out there than I am, would you have serious worries about a 20 in. deep top made from two 10 in. pieces glued together, attached to a carcass? Would you feel it necessary to add a bread board onto that? This is an arts and crafts design, and I don't believe there are tons of examples of bread boards, though I'm about to do a Google image search to find out.
I just don't want all the time and energy to be undone by some boards getting outta wack down the road.
What y'all think?
I've done 20"+ tops out of just one board, so 2 x 10" ones should be OK.
More important is to finish both sides the same, if one side is varnished and one isn't then it's going to move, no matter how many boards you have glued it up out of. You dont have to finish the bottom with the same care as the top, but get a similar film there so moisture transfer is the same.
And of course you want the wood properly dry before you build the top.
Cheers
Ian
I have incorporated bread boards into my chest tops on several occassions. The first I just joined on the edges with biscuits. Purist woodworking says that this is unacceptable, and I know agree. Not because the top failed, it hasn't and it has been 14 years. But the problem is, it has only been 14 years. 24, 34 years down the road will tell the tale.
many woodworkers neglect to remember that going through all the "trouble" to build a familky heirloom dictates thinking in the long term. 14 years is not long term. In hindsight I recognize that now.
The designs that I now use are either a floating dovetail keyway or a mortice and tenon with floating dowels.
The dovetail takes patience as with any worthwhile joinery but is well worht the time and effort. You need to clamp the top vertical and make a jig that will not allow your dovetail bit (or your straight bit w/ m&t), to exert any side to side movement between the two straight edges of your jig. Don't use a single straight edge thnking you can keep the router from drifting it is almost impossible. you need to be working with a thisk top here. 3/4" is acceptable but not ideal because then you are using bits so small that there isn't enough meat for the joint to be effective. Of course a router table or Incra type system is also ideal and makes it tons easier when routing the dovetailed spline portion of the joint, becuase making a jig to do this (trust me on this) can be an excersize in futility although that's how I did it the first time, before I wised up and used my router table.
The mortice and tenon is almost as effective and certainly easier. Just make sure the tenon length is 1/4" or so shorter than the mortice, and that you glue only the middle dowel. The other dowels need to reside in slotted mortices in the tenon, but make sure you don't leave too much space, or too little, between the slot and the dowel so that when the breadboard portion of the top expands and contracts, it doesn't get too losse, or on the other extreme, wreck the joint.
Remember how the wood will expand and contract with respect to the dowel and slotted mortice; the slot is not going to open up very much width wise when you properly orient the grain; that's good. But it will open up lengthwise; that doesn't matter much given proper clearance between the dowel and the slot ends so that too is good. What you want to remember is that the breadboard, and thus the dowel, is going to make it's movement toward and away from the end grain of the top, so the mosr critical element in the design is the placement of the dowel holes in the breadboard with respect to the slot palcement in the tenon.
hope it makes sense I didn't proof read.
Edit: i just did proof read it. ;) I would like to add that I have never actually incorporated either joint in a top as thin as 3/4", because even from the beginning of using a breadboard design in my chests I had thought that 3/4" would be the extreme low end on the thicjness i would want to attempt the design. i suppose I should have said that IMO 3/4" thickness is too thin for these jonts for realistsc long term service life. i have always used 4/4 and thicker for these tops for that purpose and also to minimize even further the cupping/warping out of flat, which is prevelant in big tops - -which is of course the mainpurpose for choosing a breadbaord design in the first place.
I use 7/8" planed stock and I've used dovetailing on the last two projects. I use a 1/2" deep x 1/2" wide at the tip of the dove tail bit. Make sure you have good quality bits for the really hard woods. The end grain is easier to dovetail (cuts faster) then the edges of boards. My bread boards are usually done on a wide board and I cut them off with a table saw at 1-1/2 widths, leaving 1/16 or 1/8th extra to run over the jointer to true up the edge. Be careful when slotting ring porous hardwoods though, there isn't much tolerance in the dove tail joint. If it's real tight, you might split it.
As Kevin suggested (I think he did) about gluing, if the boards are long just glue the ends of the bread boarding. I glued the whole length of the table top I made (30 " deep) and it's a struggle when your working against setting time and the glue itself. :D :D
Use as wide a board as you wish as long as it's not a warped board and it's been drying for a long time. Can't see no problem. All my wood is air dried 3 or more years. What I have now is all over 6 years air dried. I like boards 6-10 inches wide as a personal preference, that's all. A lot of my work I have to use stuff smaller than 5 inches wide. ;) Now wait a minute, I ain't in the same league as the New Yankee Workshop guys, but I ain't no Tim Allen neither. ;)
Best to glue just the center dowel or center of the DT joint so the joint can float so the expansion of the top will not tend to tear things apart. ;)
She won't budge. ;D Actually the desk top has shrunk 1/32" over a 31 inch surface. I think it's within tolerances. ;) Once 4-5 coats of diamond finish is applied she'll never move agin. ;D ;)
Donk, I hope that top doesn't end up splitting on you. My parents have an old cutting board that has glued breadboard ends on it, and a really nice split down the center of it. Of course, it was probably finished with oil (long gone) and often wetted and dried with repeated washings.
I love using breadboard ends on most of the things that I build. Most of the tops are also only 3/4" thick, and I've never had any problems with them. One thing I did on my last piece (a coffee table) was to use breadboards that are a little thicker than the actual top, since the seasonal movement will "break" the polyurethane finish anyway, this makes it less noticeable, and adds a little more character to the piece. Just off the top of my head, I think I made a tenon about 3/8" thick probably 1/2" long along the entire ends of the top, and three longer tenons maybe 1-1/2" long. I glued the middle tenon only, and just dabbed a little glue on the two outside pegs then they were almost "home" to keep them in place.
Paschale, I wouldn't be afraid to use two 10" wide boards, I always use the widest boards I can, and I may have to try the planer sled myself so I can use even wider ones.
I just want to see a pic of the finished table with a fresh hickory nut pie on top ;)
As the old saying goes, 'Ya pay your dime, ya take your chances'. ;D
Quote from: kevjay on January 12, 2007, 05:38:50 PM
Best to glue just the center dowel or center of the DT joint so the joint can float so the expansion of the top will not tend to tear things apart. ;)
Can you explain how that is possible?
Gluing only the center of the slot allows the opposing grain directions of the woods to avoid binding. They should have a snug fit along it's length: the dowels for the Mortice and Tendon run vertically through the breadboard, glued to the breadboard end cap but floating in an elongated slot in the tendon. Hope this helps...
Pictures:
Best Wishes,
Steve
I understand the concept, just not how you ONLY glue the center of a dovetail slot.
At the very least you must glue at least half the length in order to glue the center, or am I missing something?
Almost forgot..... Welcome to the forum Steve!
I am thinking that on a standard mortise and tendon breadboard it is necessary and possible to glue only at the center, but on a dovetailed breadboard it would only be possible to glue one end. Sliding that dovetail would spread the glue all along one half of the dovetail. I suppose a person could drill a hole in the underside and try to squirt some glue into the center of the dovetail. smiley_headscratch
Bob- just trying to learn
Gosh, Furby is faster than I am
Sorry Bob.
I guess a few of us are stumped on this.
Say I got 5 boards across the width for the desk, I run the first two boards on the end, dab some glue where the third piece comes to and add the last two boards down the dovetail and no glue. Maybe that is what they mean. That would be safe for not so dry wood. I've seen a fellow try to use wood within a year and his stuff splits a lot. Too impatient. If your using air dry wood, ya gotta wait at least 3 years, mines been air drying for at least 6 years.
I've not only dovetailed and glued the whole length of the dove tails, but I also glued biscuit joints between the boards. Who knows, maybe it will all far apart. This butternut is semi-diffuse porous and soft and I think it can move a lot more than say cherry. It has large pores that are uniform across the grain pretty much. Anyway, time will tell. ;)
With a Dovetail you don't use glue, just one dowel in the center inserted from the underside that doesn't penetrate the top. Sorry Furby, I thought that you were asking a more basic question...
Steve
I just knew I would learn something new. SwampDonkey gave me an idea. Slide the boards on the dovetailed breadboard before gluing them together. Then put a little glue in the center of the dovetail joint before clamping the boards together. 8)
Bob
Before (flush fit)
(https://forestryforum.com/gallery/albums/userpics/11009/SD_butternut_desk-dovetail%7E0.jpg)
After (1/32" movement in one week)
(https://forestryforum.com/gallery/albums/userpics/11009/SD_desk_dovetail.jpg)
Yes the ruler is graduated in 1/16th's, but it only moved half that. ;)
The only thing I can offer is to alternate growth rings on your wide boards, that way they can oppose each other if they should get into a wrestling match. ;D
SD
Sorry to see that. Gonna trim it back now, or let it ride it out?
Any idea how much moisture the top lost to shrink that 1/32" ?
That much movement can be the difference between summer and winter humidity, or a wet year and a dry. If you shave it back now, next year the end will be too short.
Let'er ride I say.
Gonna be a real trick if you are bread boarding both ends with a dovetail slot isn't it Bob?
It's not a bad idea, but I know there is no way I could do it.
If one board is off say 1/32" in length, it would mess ya up wouldn't it?
I'll touch it up before I apply the finish. At least this time of year the movement is in one direction. When she's sealed with 4 or 5 coats of diamond finish, it won't move significantly. Actually 1/32 isn't much (1/10 %) and butternut does not shrink (Vol %) as much as most other commonly used hardwoods.
Vsh%= V0-V1 x 100
V0
V0 is initial volume
V1 is final volume or volume at a future measurement
You can do a 'dry run' Furby, to see how she all fits before committing the glue. ;)
Furby, I was saying it could be done, but I don't think I am good enough woodworker to get it done right. I thing I will just keep using the regular breadboards. I believe in the KISS method. ;D
Bob
Got any Jam and peanut butter? ;D
Wow this thread really took off while I was snapping pictures! I was not clear as I thought I was, but I can see that sfixx and I are on the same page. Thanks for holding the fort down while I was gone sfixx. :)
The DT joint is not glued inside the actual joint but in the center dowel.
Quote from: Furby on January 12, 2007, 08:55:31 PM
Quote from: kevjay on January 12, 2007, 05:38:50 PM
Best to glue just the center dowel or center of the DT joint so the joint can float so the expansion of the top will not tend to tear things apart. ;)
Can you explain how that is possible?
Yes. I think I can! ??? I thought it was clear to begin with, but I can see how it could be taken literally to the extreme. The text you boldened to better ask your question, was not the area I was saying would accept the actual glue, but I was describing the area along the DT joint where the dowel is "in the center of the dovetail joint itself". It was sort of redundant really and I can see now that i am typing another explanation where I wasn't clear after all! Sorry.
I made some assumptions here that you would "be inside my head" so to speak. I think the key concept here is where I stated several times throughout this thread about "Floating Dovetails" because they can't float when you glue them. I'll try to be clearer next time. ;)
That sort of movement is just a feature of breadboard ends, 6 months time the table might have grown again and the gap will be the other way round ::)
Even after the top is varnished it will still move, just slower. Seasonal movement instead of changing with the weather
Cheers
Ian
You are right Ian but I didn't want to get a debate going with SD he is more stubborn than me.
I think everyone on the forum is aware of the fact that wood movement cannot be retsrained completely - even in sheetgoods.
Sometimes I'd love to be able to get inside other folks heads. ;D
Sometimes I do get inside other folks heads. ::)
Most times it's a job just staying inside my own head. :o
Center of the joint....... middle of the panel.
I understand how the gluing works with a standard mortise and tenon type joint just as Bob explained.
The joints can be pushed together at their respective points so that the glue only contacts where it is placed in the joint.
On a dovetail slot joint one piece is slid along the other for the length of the piece, thus spreading glue the whole way.
If there is a way to just glue the center/middle of the joint, I'd love to hear it, that's why I asked.
I never said there was. I'm not saying it now. Let it go Furby. Take a valium and call me in the morning. ;D
What's your number doc ???
BR549 - now I know you had to know that was coming. :D
Da yup! smiley_smug01
Well you know me. I'm going to go against the grain ::) and sand off that end smooth. I know stuff will still move in reality, but with that vapor barrier applied it ain't gonna move too much. ;D :-X
All the opinions in this thread are fun, thanks for allowing me to participate ;D One thing that I like to leave in handmade furniture is what differentiates it from what people buy at big box stores and "high end" furniture stores, the makers marks. I like to use hand tools and rarely shoot for perfection...I don't have that much patience and most people don't appreciate it anyway, besides I hate sanding! I'm also kinda lazy I guess...the breadboard ends on my dining room table have been slightly proud even in the summer (humid season) for 15 years now. I could have sanded them when I felt the table had expanded to its maximum width. It's pine with a Danish Oil finish and moves plenty but I would much rather it be a little proud than have the breadboard caps too short, that would look silly :o
Steve
SD
From what I've been led to believe, there are no vapor barriers that you can apply that work. The only one close to perfect is parrafin wax. Now granted, a moisture barrier is different. But wood will move when its moisture content changes, and a constant relative humidity is pretty much the only way to keep it from moving. I would imagine that slowing the movement with several coats of finish will help some.
To all
When woodworking, I think it's best to design and do the construction that will allow that wood to move and not tear the project apart.
If this Board is going to be helpful to the Forum members looking for help on wood projects, seems to me it will be prudent that good design and woodworking technique be the focus. That comes with giving it a special place to discuss woodworking in the forum.
I would like to reiterate to everyone that an important consideration in furniture building is the long term service life of the piece. I haven't been harping on it (and won't *harp* now ) because most guys don't want to talk about it, but 14 - 15 years is not really long term (remember I have a breadboard top that I joined with glue and biscuits 14ish years ago and it has not wrecked but I am confident it will at some point). That is still in the piece's infancy unless it is just a thrown-together stop gap piece to serve a temporary task, or even just for functionality alone where service life is a consideration but not paramount; say, like a kitchen step stool where you didn't really intend to make it a hand-me-down for generations but want it to be around as long as you are.
On the flip side of course, it's often that kind of piece that outlasts the kitchen table & chairs you took 3 months to build. ::)
But that relentless (and, ahem! un-stoppable, SD) seasonal movement will eventually work on any glue joint, and even any dry, pegged joint. It might take 1 year and it might take 100 years but eventually the joint can be compromised to some degree. That doesn't necessarily mean the joint will fail or that the piece will be rendered disfunctional.
I agree that, given the same overall conditions in the environment that the piece sees year in and year out, it does not make sense that the wood would move any more or less. It doesn't have to either; seasonal movement has a cumulative effect on a piece of furniture. The choosing of the correct joints, glues, grain orientation, wood species, dimensions, and yes to some extent the finish, will all affect the serviceability of the piece by either minimizing the effects of the movement of the wood, or by exposing poor choices in any of these areas.
beethere and oshscolo y'all keep trying to get SD to admit his piece is going to move more than he thinks and I am telling you HE is the one that is not going to move; on his admission of it. ;) :D
SD I am on your side buddy that top is solid as an oak! :)
This is some interesting reading, and like kevjay said, it sure took off on its own!
As to my table top, from some of the initial comments, it sounds like a bread board isn't really necessary. But...the way to attach it to the carcass is vitally important. That table top will want to spread out when the summer months hit, along with high humidity. So that's probably the biggest level of concern for me right now. There are directions in the WOOD magazine on how to do it, but I'm curious how you all like to attach a table top to a carcass like this to avoid the wood movement breaking apart the project.
Again, so many options here. If the top is kiln dried and the service environment is inside, it may not be necessary to allow the top to float, and it probably wont sreck your carcass. If the carcass ends (not sides) are not plywood, but are solid lumber with grain orientation running the same at the top, then remember your sides are going to at least "somewhat" follow the expansion/contraction of your top. Of course they are probably running perpindicular unless they are of a tall design.
Barring that, there are many ways to float the top from metal ell brackets with elongated holes to alow the fasteners to slide in them, to all manner of fancy joinery!
For a 20" top like yours on an end table I wouldn't think it is gong to wreck the carcass and that you can get away with any type of glued joinery you want from dowels to biscuits to spline and rabbet.
Hmm just re-read your post it IS air dried - before we go on what is the MC?
It's been air drying for about four years, the last year or so in the house, so it's very low...6-8% range, so it should be good to go. It's as dry as forced air heat in the middle of winter will allow. ;D
I stand to be corrected here because I am a recent study of KDing and MC etc., but even had it been KDed it would still bounce back up to whatever EMC would be there, probably more like 9 - 12%, but still okay IMHO.
I say all things considered attach it any 'ol way ya want and you're good to go! 8)
;D Well before I take anymore abuse on the subject... ::) I just wanna make a point that I will admit when I'm wrong, when I'm wrong. :P So, have not fear, come this June-July there will be a picture of this desk on this board somewhere. Now, you made me go up stairs and look real close at the joinery of my cherry bed I made back in 1995. The wood was air dried (except the legs-kilned) for about 2 years. I looked real close at the joints of that bed and could see not even a hairline split in the joints except when the headboard joins into the legs and even there it was thinner than a thumb nail. I know there had not been much movement because there is the odd spot where wood filler was applied and it has not broken (just in the previous joint mentioned). So I think I've been quite lucky.
I went and checked a display case for my salmon flies made about the same time as the bed and I see some movement there at the joints. But, no thicker than a thumb nail. I used finger joints, but not like you think of on finger jointed flooring, the fingers are 3/4" wide. There is a pic in the forum someplace buried.
Now back to our breadboard discussions. ;)
Kevin, I'de say your correct. And I don't even operate any kilns, but I have studied the subject and worked with wood. I don't claim to be no expert by a long shot as some might elude to with wide swiping brushes.
A humbled Swampdonkey. ;) ;D :D :D
SD I don't think anyone is saying your stuff is gonna wreck. I'm not anyway. I kid with ya cause you can take it but I'm just saying that the consequences of improper application of techniques like types of joinery etc, like I chose 14 years ago (and it looks still good too) are not necessairly going to show up (if ever, granted) in the first 10, 15 years.
As for me, I know I chose the wrong type of joinery for my breadboard at least IMO. I have a pretty good idea that one of my son's, daughter's or one of their kids is gonna look at that Ash top with the walnut breadboards about to fall off and say "Ol grandpa Kevin sure didn't know how to make a breadboard that would last did he?" ::)
Kevin, and All .. I have been following your advise and insight on this thread as well as others. And I think most if not everyone can make use of the information we share and draw on our own experiences and make our own decisions. If you try something and it don't work, I for one ain't going to be blaming anyone. What works for me, might not for you. There is no method in the world that is fool proof. If we are all going to be worried about what information we share , we might as well go to our shops and close the door because the attitude/atmosphere in here is going to be that 'nobody knows nothing but me'. ;)
Right from the start, if you read my posts on my projects in the Drying and Processing board I was just sharing with everyone my progress as I worked on them. Kind of like a blog of sorts. They weren't meant as instructional text with photos, but just what I was doing and how. Just a way of showing how things are coming together/unfolding toward a finished piece of furniture.
So with that all being said, you know where I'm coming from. After I get this desk built, it's time to concentrate for awhile on the book. What better place than a nice new butternut desk to work on? :)
Have a good one. ;D
Quote from: Paschale on January 13, 2007, 12:21:11 PM
As to my table top,............ There are directions in the WOOD magazine on how to do it, but I'm curious how you all like to attach a table top to a carcass like this to avoid the wood movement breaking apart the project.
On end tables, night stands and other small tables I usually put corner braces in and screw through the brace into the top. I will use a slotted hole in the brace and sometimes drop the brace down 1/4 in from the top to give the screw a chance to shift some. On larger tables with aprons, I will cut a dado along the inside of the stretchers and use small wooden L brackets to secure the top. On thicker tops without aprons I just use slotted holes in the support members to fasten the top. Metal figure 8s are good to fasten tops, but I have never used them, I like to do things the hard way.
Bob
Quote from: Paschale on January 13, 2007, 12:21:11 PM
I'm curious how you all like to attach a table top to a carcass like this to avoid the wood movement breaking apart the project.
Like this.
(https://forestryforum.com/gallery/albums/userpics/10125/table4.jpg)
Got a whole bag of tricks but this is the only picture I have...and like Bob I detest store bought clips sold for table tops.
My breadboard solution...but you have to understand my brain has been warped since birth. Leave a 1/4" crack or two right in the center of your panel. Pin the panel to the breadboard at the end of the breadboard. No glue other than at the pin. The panel is free to expand and contract at your 1/4" cracks. Don't think this would work for SD but for Paschale building in the arts and craft style the crack could be considered a design element...and presto your work will command prices in the millions. If you think this method is weird I got one using pins and copper rods...it's beyond words so I'll have to dig out the camera.
Larry, I haven't used the wooden L brackets on that kind of support, but I like it and will try it on my next table of that type. 8) Learn something new every day.
Bob
I have been wracking my warped brain to come up with an idea to mount that desk top. I know how the upper shelves are going to sit on the top, with dowels so I can take it off, even though the whole thing will be around 5 feet high, and I'm not likely to ever take it off once it's on there. ;D At this point I'm thinking to use brass L brackets on the corners, they will be mostly hidden anyway and won't be too obvious on finished butternut. Certainly dowels at each corner isn't going to cut it. Still cogitating
I like this new board--I feel like I'm gonna learn a lot! 8)
Paschale,
Are you using the BB ends because of the plans, or because you like the look?
BB's I thought were to stabilize an insecure top. If you think your top board is stable (dry, sawn correctly, machined correctly, blah, blah...) then you may not need the BB. However, if the rough sawn board had plenty of twist or cup, then the BB's are the way too go. They just create another cross grain situation. I usually use a long mortice and tenon with the center pegged.
If you are worried about the endgrain showing and use the BB to cover that up, then properly sanding and finishing the endgrain will solve that.
I appriciate real wood and what real wood will do. A 20" board incorperated into a piece of furniture you built is truly special. If the board moves a bit or cups a bit over the years, well, that would be fine by me. That just proves that it is a real piece of wood. A 20" flat sawn piece of ash will move the same amount wether or not it is one board or glued up from several boards.
Larry's pic of the wooden buttons is a great explanation as to how to allow wood to move like it wants.
SD,
I once secured a top using two keyhole slots routed under the top aligned with the apron. A panhead screw in the top of the apron and screwed down just right kept the top tight to the apron. The slots of course allowed the top to move whichever way it wanted.
metalspinner, thanks for giving me something to think about. ;)