# Oak tabletop on plywood base with limestone center



## FireFlower (Dec 6, 2010)

Need some experienced advice on my table. I started with this amazing slab of limestone loaded with fossils - its 26 x 26. My plan is to make it the center of a table 50 x 50. I have the quartersawn oak to surround the stone, see the picture. I have a 48 x 48 sheet of quality plywood as the base to hold the stone and attach the oak. What's the best solution for joining this all up so the solid oak expansion doesn't kill the table?

I read alot of the discussion about joining solid wood trim to the edge grain of tables... but I still don't know about joining the oak to the plywood itself. I could probably live without the trim if needed.

My thoughts are to secure the four oak boards along the inside edge (next to the stone) and let the boards float on the plywood away from the stone, but that won't keep the edges from lifting up if someone tries to pick up the table by the edges and move it...

Any advice is appreciated...

Thanks
Chris


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## cabinetman (Jul 5, 2007)

*WELCOME TO THE FORUM*

You could just attach the pieces and the stone to the plywood with construction adhesive. If you have to screw it down, use screws close to the stone from underneath, close to the stone where indicated. As for the edging, it can be glued to the pieces opposite the indicators. IOW, don't glue the edging where long grain meets cross grain. You might get lucky and have no movement, if the wood was acclimated and lives in a fairly humidity controlled area.
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## FireFlower (Dec 6, 2010)

*Thanks*

I do live in a very low humidity area - high altitude as well. 6000 ft and normally around 20% relative humidity. 

Follow up question on the adhesive: I have gorilla glue. Is this what you meant or do I need something different?


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## cabinetman (Jul 5, 2007)

My suggestion was "construction adhesive", like Liquid Nail, NOT Gorilla Glue. 












 









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## wwinsauer (Dec 7, 2010)

I live in a very high humidity area, San Antonio TX., 60%+ most of the time and I use Tightbond II with great success. Use liquid nails on the limestone and tightbond II on everything else. 

As for the edges, get a 1/8" slot cutting bit for your router, center it on the edge of your table and run a slot all the way down all the edges. Also run this slot down the middle of your trim pieces. Make sure to 45 your corners to hide the slot unless you want to show off this spline joint. Run a hardwood board down the tablesaw to 1/8" thickness, the length of your current edge and 1/16" thinner than double the width of your slot cutters depth of cut. 

Smear tightbond II on all sides of the spline and insert into the slot on the table. (DRY FIT BEFORE GLUING) Spread glue along the flat part of the trim piece then using a rubber mallet gently tap it on to the spline. be sure to clamp everything securely after gluing and wipe off excess glue with a disposable damp cloth. 

The spline joint will ensure that long grain will be joined with long grain through the length of the spline. The end grain will be glued to side grain as well, but the spline will be doing all of the work. If you want to be extra cautious, Make your spline out of smaller segments of 1/8" boards where the grain runs out away from the table rather than along with the edge. This will ensure that the spline doesn't split and eventually weaken or fail but will require quite a bit more work.

Hope this helps,

Wayne


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## FireFlower (Dec 6, 2010)

*update*

Thanks for the detailed info on the spline attachment of the trim. I will go with that, but I don't want to miter the corners because its a 'modified' mission style and won't go with rest of the furniture. I plan to stop the spline/slot a bit short of the ends of the trim so I can keep a butt joint at the corners.

I have the table upside down now (man is it ever HEAVY) so I can attach the legs and apron. I have attached the oak boards but not the stone yet. And here's my next puzzle - the stone is almost level and uniform... Since I didn't work that piece it is what is it is. When its sitting in the pocket one side is 1/16 lower than my perfectly level oak. The other side is flush with the oak. Here's my options:

1. Build up beneath the stone to raise that side. I can iron on a strip or two of edge veneer to the plywood base. This will involve alot of heavy lifting going back and forth flipping the table to get the stone out until I figure out if 1 or 2 strip thicknesses of veneer with make it flush.

OR

2. I could use gravity to my advantage and build the table upside down. Meaning lay the stone upside down on a flat surface, put adhesive on the stone then drop the table on the stone upside down and let it cure. The stone and wood surfaces should be flush and level on the flat surface. This would only work if I use an adhesive that would fill the 1/32 to 1/16 gap beneath one side of the table. Its pretty small... I read that the gorilla glue I have will expand 3 to 4 times and maybe this will fit the bill? Or is Liquid Nails good to go for this? 

Opinions/advice on the merits of these 2 options or give me other options that are better?

Thanks a ton for all the help! I will take/post a picture later to help visualize...
Chris


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## wwinsauer (Dec 7, 2010)

I would use option 1. not option 2.
I think if you try to glue upside down you will create all kinds of PERMANENT problems that may not be fixable. Keep the table right side up and despite the extra work you will be able to see what is going on.

Do not use iron on adhesive. It will not be strong enough. Either use plain wood veneer or rip a few edges from a board on your table saw or band saw. band saw might be better. Prop up the non level part of the stone and dry fit. if you cut a little oversize just use your sander to take it down to the right thickness. 

Use tightbond to secure the shim to your tabletop. Also you probably dont want the shim to abut the oak. leave a 1/2" to 1" gap between the shim and oak so that the liquid nails can seep over both sides of the shim after you press the stone down. 

Also be careful about the amount of liquid nails you use close to your oak / stone transition. I don't remember the clean up methods for liquid nails but regardless, if it seeps out over the edge onto your oak, I think you will be very dissapointed with how it will stain and or finish.

Use liquid nails out of the caulk gun with about a 1/4" nozzle and squeeze out squiggly patterns onto the substrate (table). DO NOT smooth out the glue! Press down firmly and wiggle the stone into place. Liquid nails has a lot of holding power even when filling LARGE gaps like 1/16". Just be sure to give it about 48 hours or more before stressing it. It should tack well in about 24 hours with that size of gap.

You may want to talk to some of the guys here on finishing methods as well. I would probably tape and plastic the oak and use a stone sealer like those used on travertine, (local hardware store) for your limestone. Limestone is extremely absorbent and will need to be sealed. You should be able to spray on a few coats rather quickly but read the instructions for the one you buy. Also, I wouldn't try to achieve a hgh gloss or even semi gloss finish on the limestone. It will look very unnatural and cheap in my humble opinion.

Now for the oak. Tape and plastic the stone after it has dried for sure. Since it is a table. You may want to close off the deep pores of the oak grain with a grain filler or sanding sealer then stain or not and finish. I don't claim to be a finish expert by any means, so please ask around for suggestions on what will hold up and give you the look you want. IE: High gloss, semi gloss, satin, etc. Oil, or polyurethane etc. I have used satin and semi gloss polyurethanes on tables for their ability to handle abuse, but again someone else may have some better advise for you here.

Good luck with your progress and keep us updated!

Wayne


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## FireFlower (Dec 6, 2010)

*progress*

Here's some pictures of the progress. I stained the legs and bottom of the plywood base ahead of time. I used GF Espresso gel stain. The shop supervisor in the background is Echo - not scared of loud machines or flying dust. I dry fit the legs and apron, then glued and clamped and screwed together. Now everything is right-side up - limestone not mounted yet. I decided to seal the limestone while its still separate. The last picture shows the stone - you can see its full of fossils.

Not shown - I spent today working on the splines and routering the grove in the trim and table edge. I'll take some picts tomorrow. I found it pretty challenging to create the 54 inch long splines on my table saw. All sorts of interesting things happen when I'm cutting an 1/8 inch strip. My practice pieces were ~12 inches long - no problem. Found out why you need a featherboard and what exactly kickback feels like. Yikes. 

Thanks for all the great advice Wayne. I appreciate it!

Chris


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## woodmeistro (Jul 9, 2010)

Good looking table, I like the style. Mission and shaker are my favorites. keep us posted


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## Geoguy (Feb 22, 2008)

Great lookin' table. Nice job on the legs and trim pieces. I especially like the limestone. Have you identified any specific fossil class, order, family, genus, etc.? Just kiddin' - I'm a fossil geek.


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## FireFlower (Dec 6, 2010)

*Finished!*

Just in time for the christmas eve party - Here's the table with limestone in place. I put a close up of the limestone - I'm a fossil geek too. I just couldn't find a nice slab with crinoids (my favorite). These appear to be mostly mollusk shells and other shell trash. Let me know if you spot something you can identify...

Thanks for all the advice on this project. Next up: finishing the bar cabinet my Dad made me to match. It will have the same limestone top....

Chris


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## DannyT (Apr 26, 2011)

great looking table. slots along the perimeter for the screws would still let it expand and contract, just snug the screws.


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## MidGAOutdoor (Apr 7, 2011)

FireFlower said:


> I do live in a very low humidity area - high altitude as well. 6000 ft and normally around 20% relative humidity.


must be nice. it around 80% here in GA.

BTW nice idea on the table top.


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