LumberJocks

White Oak Dining Table

  • Advertise with us

« back to Joinery forum

Forum topic by Joeymds posted 01-06-2018 01:46 AM 634 views 0 times favorited 14 replies Add to Favorites Watch
View Joeymds's profile

Joeymds

6 posts in 223 days


01-06-2018 01:46 AM

Topic tags/keywords: white oak table dining table wood oak

Hi, I am building a table and want to make Sure I allow for wood movement as I design it.

I am Using 8/4 white oak for the table top. It will be 40” wide by 80” long.

In my attached picture I have three braces I was going to mortise in to the bottom of the table to keep all the boards straight over time.

My issue I’m running into is how to attach the legs to the tabletop to allow for movement. I don’t want to just use the rockler tabletop wing brackets because I feel like I will need more support with such a heavy tabletop and also do not have any aprons to attach them to. If I just screw lags into bottom from leg braces will that prevent expansion? I have been searching everywhere to try to figure this out any help is appreciated. Thank you!


14 replies so far

View jerryminer's profile

jerryminer

937 posts in 1524 days


#1 posted 01-06-2018 01:53 AM

I’m not totally clear on your leg structure, but , in general, yes, you can drive lags or screws up into the top as long as those screws are in slotted holes that allow for wood movement.

-- Jerry, making sawdust professionally since 1976

View LittleShaver's profile

LittleShaver

346 posts in 702 days


#2 posted 01-06-2018 02:00 PM

Here is how I handled a similar build.
There is a tapered sliding dovetail that runs the full width of the top. Seems to be holding up well so far. It’s been in use for about 7 years now.

-- Sawdust Maker

View bondogaposis's profile (online now)

bondogaposis

4895 posts in 2433 days


#3 posted 01-06-2018 02:31 PM

If I just screw lags into bottom from leg braces will that prevent expansion?

You can’t prevent expansion, you have to allow for it. If you use slotted holes in the cross braces then the top can move freely and that will be fine.

-- Bondo Gaposis

View Tabletop's profile

Tabletop

138 posts in 830 days


#4 posted 01-06-2018 04:28 PM

Bondo is correct. Lag bolts with slotted, or oversized holes will work. Also for a table that size why put the brackets. 8/4 oak over a 7 ft span with legs spaced from end like the picture will be more than adequate. I’ve built a 20’ x 48” 8/4 walnut conference table that had 4 legs similar to those pictured with no support brackets. It’s been used for about 15 yrs and still looks great.

View Joeymds's profile

Joeymds

6 posts in 223 days


#5 posted 01-06-2018 06:25 PM

The Other pictures are of how I want to do the legs. The drawn out paper part is the base the table top will rest on. Where do you think I should put the lags through for the tabletop? And do you think I should use the same wood for the legs?

View jerryminer's profile

jerryminer

937 posts in 1524 days


#6 posted 01-06-2018 07:32 PM



I m not totally clear on your leg structure, but , in general, yes, you can drive lags or screws up into the top as long as those screws are in slotted holes that allow for wood movement.

- jerryminer

I mis-read the question. Bondo is right, you will not prevent wood movement. You need to allow for it.

I would lay out the screw pattern something like this:


Center holes are not slotted, which will keep the top centered on the base. Other holes are slotted.
I also think the let-in steel braces are over-kill. 8/4 cross braces should be enough to keep the top flat.

-- Jerry, making sawdust professionally since 1976

View Joeymds's profile

Joeymds

6 posts in 223 days


#7 posted 01-06-2018 08:11 PM

Ok that’s great info thanks. First table I’ve built and I just looked how restoration hardware and other manufacturers made them and they had those braces and I just wanted to do it right so it lasts but if you think it’s overkill than I would rather not do them!

Also do you think I need dowels in betweeen each board or maybe biscuits? Or am I fine just glueing the edges straight?

View jerryminer's profile

jerryminer

937 posts in 1524 days


#8 posted 01-06-2018 08:24 PM

Long grain-to-long-grain butt joints (which is what you’re doing) are fine with glue only, as long as the butt joints fit tightly.

Some people use dowels or biscuits to help with alignment of the pieces during glue-up, but they are not needed for structural purposes. Personally, I prefer to use curved cauls during glue-up to keep everything aligned.

How are you planning to attach the legs? This looks like the weak point to me. A traditional table would have an apron, with mortise-and-tenon joints into the legs, providing anti-racking strength. What method are you using to A: attach the legs? B: provide anti-racking?

-- Jerry, making sawdust professionally since 1976

View Joeymds's profile

Joeymds

6 posts in 223 days


#9 posted 01-07-2018 06:28 AM

I haven’t thought thought too in depth on the legs yet. Open to suggestions. I was thinking just using pocket holes for all the joints on the legs?

View Woodknack's profile

Woodknack

12227 posts in 2462 days


#10 posted 01-07-2018 06:34 AM




- Joeymds

This doesn’t look like a good table leg design. Legs are not usually attached to the top. Instead you build a rigid structure and attach the top to that. The exception would be mid-century legs or peg legs but those are usually splayed.

-- Rick M, http://thewoodknack.blogspot.com/

View jerryminer's profile

jerryminer

937 posts in 1524 days


#11 posted 01-07-2018 07:40 AM



I haven’t thought thought too in depth on the legs yet. Open to suggestions. I was thinking just using pocket holes for all the joints on the legs?

- Joeymds

I suggest you think about this some more. Pocket screws work well for cabinets—plywood boxes that get screwed to the wall of a building. Furniture has to handle stresses that cabinets do not: they get moved, bumped into, leaned on, etc. Pocket-screwed butt joints would not be up to the task, IMHO. If you want this table to stand up over time, you’ll want to use a sturdier system: box joints, double mortise-and-tenon, or something.

-- Jerry, making sawdust professionally since 1976

View Joeymds's profile

Joeymds

6 posts in 223 days


#12 posted 01-07-2018 08:09 AM

Ok thanks. Would you use double mortise and tenon on both ends of the vertical legs or would you want to use it on every piece in the bracing system(ie all the horizontal pieces)?

View jerryminer's profile

jerryminer

937 posts in 1524 days


#13 posted 01-07-2018 11:06 PM

This type of “contemporary” table is not something I typically do. I am more of a “traditionalist” and my tables have aprons—I like “tried and true” methods.

But IF I were to design a table like this, I would probably do something like this:

I would probably eliminate the center section of your table base (seems superfluous to me)—and I would change the screw layout to something like this:

and end up with something like this:

I still think the leg structure is weak—but possibly strong enough. I might consider adding an end apron and center stretcher, something like this:


If you were to take this route, the bottom stretcher would not need the multiple mortises (and could probably be installed with pocket screws if you like, as the structural load would be minimal)

-- Jerry, making sawdust professionally since 1976

View Joeymds's profile

Joeymds

6 posts in 223 days


#14 posted 01-08-2018 04:13 AM

Alright this was all very helpful. Thank you again

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