LumberJocks

Noob making a simple table

  • Advertise with us

« back to Designing Woodworking Projects forum

Forum topic by HalPlz posted 02-22-2018 08:03 PM 389 views 0 times favorited 8 replies Add to Favorites Watch
View HalPlz's profile

HalPlz

2 posts in 115 days


02-22-2018 08:03 PM

Hello all,

I’m looking to build a simple 5’ x 3’ table, with a marble slab inlaid into the center. I was just going to start with a base, probably a piece of plywood, and then glue the wood down onto it. My question is, will the plywood board provide enough support, or will it eventually bend or droop?

It seems like making a frame as support for the table top is the usual way to do it, but I don’t want anything below the table top, and i don’t want to have to make the frame.


8 replies so far

View Snipes's profile

Snipes

177 posts in 2267 days


#1 posted 02-22-2018 08:12 PM

What is your plan for the legs? Gluing wood to plywood is never a good idea, unless its veneer.

-- if it is to be it is up to me

View Smitty_Cabinetshop's profile

Smitty_Cabinetshop

15366 posts in 2640 days


#2 posted 02-22-2018 08:17 PM

Gluing solid wood to a plywood underlay is always a bad idea. Solid wood needs to move, the plywood / adhesive combo will (unsuccessfully) work to prevent it.

Marble inlay will mean weight. Wracking (think ‘leaning against the table’) forces are what frames combat in the name of stability.

If you don’t want to have (or make) a frame to support the top, what’s the plan? Nail through the plywood substrate into the ends of 2×4s? That’s won’t work. Maybe look into staked furniture for ideas contrary to the standard frame / apron dynamic. Or consider trestle table forms.

Hope this helps in some way. If not, still worth what you paid. :-)

-- Don't anthropomorphize your handplanes. They hate it when you do that. -- OldTools Archive --

View bondogaposis's profile (online now)

bondogaposis

4754 posts in 2373 days


#3 posted 02-22-2018 09:59 PM

It seems like making a frame as support for the table top is the usual way to do it, but I don’t want anything below the table top, and i don’t want to have to make the frame.

Ok, so what is your plan? Traditional methods evolved over hundreds of years because that is what has worked. Hint, mortise and tenons are your friend. You have to have something to attach the legs to, you can’t fully design the top until you figure that out.

-- Bondo Gaposis

View Jon Hobbs's profile

Jon Hobbs

147 posts in 726 days


#4 posted 02-22-2018 10:45 PM


It seems like making a frame as support for the table top is the usual way to do it, but I don t want anything below the table top, and i don t want to have to make the frame.

Sweet, the world’s first levitating marble table! I can’t wait to see the finished product!

:)

-- Jon -- Just a Minnesota kid hanging out in Kansas

View HalPlz's profile

HalPlz

2 posts in 115 days


#5 posted 02-22-2018 11:59 PM

Ha, ok I deserve this. But what I was looking to do, looks like it might fall under the category of the mortise and tenon that bondogaposis brought up. Where the table top + plywood would be the Mortise (a hole made through both layers) and the table leg would be the tenon (the top key portion would fit through the holes). All 4 legs would be independent of each other and detach, like some ikea table legs do.

That’s not going to work?

View chrisstef's profile

chrisstef

17421 posts in 3028 days


#6 posted 02-23-2018 12:19 AM

Again without an apron of some sort that puppys gonna sag like An old pair of bvd’s. All you have for support would be a couple inches of material on each leg.

It seems like you want to build something but want it quick and relatively easy. Thats cool. Take a look at a pocket hole jig. You can do easy with that.

You do it the way youre saying and youll be building twice.

-- Its not a crack, its a casting imperfection.

View Lee's profile

Lee

116 posts in 900 days


#7 posted 02-23-2018 12:52 AM

If you dont want an apron showing try building a frame from 1/4 X 1 1/2 angle iron. put in on the inside of the legs, paint it black and it will be very hard to see unless you crawl under the table. I would weld the four pieces together but you dont have to. Cut an 1 1/2 deep V in the tops of the legs so the angle iron sets on the rabbit then drill holes in the iron and screw it to the legs.

-- Colombia Custom Woodworking

View Jon Hobbs's profile

Jon Hobbs

147 posts in 726 days


#8 posted 02-23-2018 07:10 PM


Ha, ok I deserve this.

Sorry for the gentle hazing :) glad you took it in the spirit it was intended.


All 4 legs would be independent of each other and detach, like some ikea table legs do.

Leaving the 4 legs independent (more specifically, only connected at their tops by the tabletop), takes us back to Smitty’s comment about racking. When a sideways force is applied to the table top, that force is going to push the top of the table legs sideways. The force of friction applied by the floor to the bottom of the legs will want to keep the bottom of the legs in place (an anal physicist might say that friction is pushing the bottom of the leg in the opposite direction of the top of the leg). So now you have the top of the legs moving sideways, but the bottom of the legs staying put. All with the weight of a heavy marble table top pushing down on the whole deal.

It’s very likely one or more legs will buckle-under and collapse. Which could set off a chain reaction and cause the other legs to collapse. And now your nice, heavy slab of marble is heading in a downward direction in a big ‘ol hurry!

The primary difference between your table and the Ikea table you wish to emulate is the weight of the table top. The heavier the top, the greater the sideways force at the top of the legs becomes. Likewise, the heavier the top, the more friction exists between the bottom of the leg and the floor, and thus the greater the force pushing the bottom of the leg in the opposite direction. Not to mention the weight of the table top pushing down on legs while they’re leaning is greater with your marble top vs. the Ikea top.

The top of the Ikea table is light enough that these forces are small enough that leg collapse is unlikely (hopefully). With a slab of marble as the top, these forces increase significantly placing greater stress and strain on the legs.

The traditional way of dealing with these horizontally opposed forces is to connect the legs to each other at a point lower than the tabletop. That way they provide mutual support to one-another that counter-acts their desire to fold-under when the table top is pushed sideways.

Making your legs beefier and placing them as close to the corners of the tabletop should also lessen their tendency to rack under sideways forces.

Plus, let’s not forget that Ikea has gotten in hot water recently because their design(s) were not safe and children died. Something to consider before duplicating their designs verbatim….or worse – altering part of the design but not modifying the rest of the design to match ;)

-- Jon -- Just a Minnesota kid hanging out in Kansas

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