curved breadboard ends

[splinna]

I am curious about the joinery technique for creating these curved breadboard ends.  

 

My guess is that there must be a shallow mortise that accepts the full thickness of the top, and is just deep enough to hide the end of the panel, but that there must be a narrower mortise in the center for a standard 1/3 thickness of the panel tenon that must be on the top.  Is that the correct way to build this detail?

Is there a better way?

Here is an example of what I am talking about:
http://cdn1.thewoodwhisperer.com/wp-content/uploads/niks-hall-table-5-950x600.jpg

Thanks,

Steve

[wdwerker]

Pattern routing , use a router with a wing cutter with a bearing and a template. There is a method to make one master template and use it to make a mortice and tenon side template. I forget all the steps involved and just look it up each time the need arises. It does require several of the collar/bushing template guides to create the required offsets. I use MDF for template stock.

If you are working with expensive wood I strongly suggest you practice on something cheap like poplar.

If you have access to Darrell Peart's book Design elements for Greene and Greene he covers making a straight breadboard.

[splinna]

Hi Steve - thanks for your quick reply.

I have made a number of straight or standard breadboards in the past.  I guess my question is more focused on what is happening between the full width panel and the curved breadboard end here.  I can't imagine that the curve of the breadboard is duplicated on the end of the panel section as that would seem to be prone to showing any imperfections where the two curves were not perfect.  Plus there would be opportunities for minor gaps to open up at the point of the cloud lift like transitions...

So I have to imagine the full thickness of that panel must be let into the end by some amount before it is thinned to a more standard tenon thickness.  I am just looking for some confirmation that this really is the case or is there some other tricky technique going on or something I am just not thinking through.

 

If I had to imagine how I could try to duplicate this, I guess I would create a wide mortise in some squared up stock with a router or chisel, then a narrow mortise centered in that one, then go back and band-saw in the curve... but maybe you are right that a slot cutting bit could work too if you cut the curve first.  I think that would leave a lot of clean up on the ends with a chisel though....

-Steve

[wdwerker]

Nope, just the tenon goes into the breadboard. Template keeps the 2 curves pretty tight. You will want to trim the ends of the tenon on each side to allow expansion. If the breadboard was flush with the top there is usually a tiny "vee" groove, with a thicker breadboard I would put a tiny vee groove on the shoulder of the tenon/tabletop. Sometimes we create way too much work for ourselves trying to reinvent the wheel .

[wdwerker]

I just zoomed in on the picture you linked. They rounded the shoulder of the top/ tenon as well as the edges of the thicker breadboard. It creates a nice shadow line that enhances the joint.

[krtwood]

I would do it the way you were thinking.  Even if you got the two to mate perfectly the top is going to expand and contract so it's only going to match some of the time. I'd maybe do some loose tenons along with the big recess.  I don't see the point in making things more complicated than they need to be.

[ChetlovesMer]

Steve, I have to agree. I would think sticking some of the main panel into the breadboard end would be easier and hide a lot of flaws.

 

If anyone has any documentation on this, I'd love to see it.

[splinna]

Where I struggle with this though, is if the main panel goes into the breadboard end, it hides flaws, and it mitigates any expansion and contraction issues in the middle with the cloud lifts, but then the panel is  "captured" in the breadboard end and it seems you could have issues at the far ends with either a gap opening up, or blowing out the end of the breadboard....  I just can't wrap my head around how to have a good looking joint that matches up perfect and stays that way through any seasonal changes as you would normally expect with a standard breadboard end.

[ChetlovesMer]

Me either.
That's why I'm hoping somebody posts documentation on it.
I'm not smart enough to figure it out.

 

Sorry.
I'm interested in the answer though.

[krtwood]

You would put a shoulder on the ends of the table top. Think of it like the normal breadboard ends you are familiar with but the tenon is the full thickness of the top.

 

I think I would do the mortise in the breadboard end first, and then fill it with a scrap piece to protect the top edge when cutting out the shape. 

[wdwerker]

What kind of wood is your top and how wide and thick is it? Air dried or kiln dried? Let me know and I can calculate the maximum your top should move as the humidity changes.

The cloud lift area is not very deep or a sharp change, it is a gradual curve and has rounded corners. Copy and save the picture you supplied as a sample, then zoom in close and inspect the joint. A full mortice for the complete top thickness would leave a very thin edge above it. You would need to round it over before you cut the mortice if you are going to route it, or be very careful by hand sanding if you do it after the full thickness mortice is cut, that edge will be fragile ( or oversized and look awkward )

I think you are worried over nothing. The sample top has a slight sloped/ rounded shoulder on the tops profiled and tenoned end where it goes into the breadboard. This will provide a shadow line that enhances the joint and will hide any seasonal movement.

The great thing about building handmade furniture is that there are many ways to acheive something. If you still want to do a full mortice I strongly suggest you get some poplar and do a practice run before you cut any nice expensive hardwood.

[dwacker]

I cant tell how he did it but you can possibly ask him on his blog, Digital Woodworker.

 

I'd just make a stepped flat bottom mortice. The top goes into the first step and the regular tenon goes into the second step, notch the ends of the top 3/16 each side.

[splinna]

I don't have a specific project in progress right now, but I do most of my work in quartersawn white and red oak, depending on availability with a local guy who runs a kiln.  I have had my eye on this design detail for a while and sooner or later want to get around to incorporating it into a project when I find the right one.  I agree the top and bottom sidewalls would be thin - about an 1/8 of an inch, and very fragile.  I zoomed in as suggested and I just don't see the rounding on the top profiled end.  I see it on the breadboard obviously, and I see it on the front edges of the panel, but I just see what looks to me as a shadow line on the top.  

 

Looking at it really closely though makes me think I see some variation in the shadow line near the ends that could be an indication of a shoulder on the main panel and that it could be inset into a very shallow stepped mortise...  hmmmm.

 

I did go ahead and post a question on Nik Brown's (Digital woodworker) blog to see if he would enlighten us on technique and included the link to this thread.

[nikbrown]

Sorry for the delay in responding I just found the comment on my blog lost among spam

 

You guys are on the right track, think of the top as a full sized tenon in some ways. The ends of the top do have a shape very similar to the inner curve of the breadboard but without the drastic cloud lift notch its just a gental curve. The end fits over the top with about a 1/4" mortice.

 

 

I've drawn a line in the photo below to simulate what the inside of the cap looks like. I just left an 1/4 of an inch or so for expansion and contraction on the ends. 

 

Hope that clears things up.

[splinna]

Now I am the one slow to respond....  Thanks so much for following up and sharing how you did this.  Much appreciated!