LumberJocks

Mitered Dining Room Table Top

  • Advertise with us

« back to Joinery forum

Forum topic by Dj1225 posted 04-10-2016 01:09 AM 420 views 0 times favorited 5 replies Add to Favorites Watch
View Dj1225's profile

Dj1225

57 posts in 1680 days


04-10-2016 01:09 AM

Topic tags/keywords: miter joint table top expansion

I have a friend that wants me to make her a 8 ft dining room table. Base in Walnut, top in ash with a walnut inlay.
I have some 6/4 dry ash (6 to 7%) and walnut. I had planned on glueing the interior ash to 27 inches wide, probably 5 boards. Then use a 6/4 inch walnut board and glue this to another 6 inch ash board, then 45 the ash/walnut board to create the inlay and achieve a 42 inch wide table top.

I had planned to use domino’s (2 each ) in all the miters, tight bond 3 glue, and then just for added security counter sink and screw two 3 inch timberpro screws, and cover with a dowel or walnut peg for a little extra embellishment.

A good friend and a great woodworker said I will still have movement and the joint will eventually open. I know this would be likely with a 3/4 or maybe 4/4 top, but 6/4???

I would certainly seal both the bottom and top of the table top, for added resistance to moisture.

But I don’t want to waste all this nice wood and time if in the end the table top is going to be problematic.

Any advice would be greatly appreciated.

Thanks
DJ

-- Dave


5 replies so far

View JBrow's profile

JBrow

816 posts in 380 days


#1 posted 04-10-2016 03:47 AM

Dj1225,

I am a little confused by your description. But from what I can infer, the walnut “inlay” will actually be full 6/4 walnut forming a rectangle in the field of ash. If this is the plan, I suspect wood movement will eventually crack the top and/or open some joints.

From what I know of the power of moving wood, no amount of fastening, gluing, and jointing will tame wood movement. I am thinking the ancients inserted dry wooden wedges into holes drilled in a block of granite that they wanted to split. They poured water over the wooden wedges until the wood swelled and split the granite. Based on my personal experience I came to understand the power of wood movement when I installed ¾” thick x 3-1/2” wide oak banding around the perimeter of my work bench with dovetailed edge banding corner joints. Even with a film finish applied to the work bench, it was not long before the dovetail joints opened up by a fair amount. Since this was edge banding, the top did not crack.

Perhaps a surface inlay of walnut may work, but I doubt it. Hopefully someone with surface inlay experience can agree or refute my conclusion.

On the other hand, if you are up for the extra work and your friend agrees, the top could be an end grain top, that is the end grain of the ash and walnut form the top and bottom surfaces of the top. With this method, the rectangular walnut band in the ash field could work. All the grain would run parallel. The only issue with wood movement would be the differential movement between ash and walnut. I checked the Wood Database and saw that the rates of expansion of American White Ash and Walnut are very similar leading me to believe that differential wood movement may not be a problem. And an end grain dining room table top would likely be a one of the kind piece.

View jerryminer's profile

jerryminer

528 posts in 902 days


#2 posted 04-10-2016 06:20 AM

I know this would be likely with a 3/4 or maybe 4/4 top, but 6/4???

- Dj1225

Listen to your friend. It is the width that matters most with wood movement here, not the thickness (but why would you presume that a thicker board wood move less than a thinner one?)

You are considering making a fundamental “beginner’s error” by mitering a 6” wide band around a solid-wood 27” wide panel. That center panel will move. “Sealing” with a finish may slow it down some but will not stop it.

Either the expanding panel will push open the miters, or a shrinking panel will create gaps.

You could inlay a strip of walnut into a solid 42” wide ash top—but you should keep the grain direction of the walnut the same as the ash. In other words, use “short grain” strips across the ends.

Don’t make this mistake:

from this post: Lumberjocks

View bondogaposis's profile

bondogaposis

4024 posts in 1812 days


#3 posted 04-10-2016 12:32 PM

It’s called the “panel of doom”, don’t do it. Wood movement will open the miters. Read about it here.

-- Bondo Gaposis

View AandCstyle's profile (online now)

AandCstyle

2565 posts in 1717 days


#4 posted 04-11-2016 12:05 AM

Dave, veneer is your friend. Use a substrate such as MDF and veneer the top and bottom. The top can be as fancy as you like and the bottom can be very plain Jane, but must be there. Then edge band the top for a solid look. That way you will save a lot of quality lumber and “need” some new tools. ;) HTH

-- Art

View rwe2156's profile

rwe2156

2190 posts in 941 days


#5 posted 04-11-2016 12:54 AM

It could work if the grain is all oriented the same direction.

-- Everything is a prototype thats why its one of a kind!!

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com