# Folded Slab table



## crworld (Feb 18, 2009)

I wood like to build a folded slab coffee table and desk from some wide slabs (20 to 30 inches wide by 2 to 3 inches thick). Any tips for how to cut and join the 45 degree angles for this type of joint?

I have seen some in commercial locations where the joint is re-enforced with angle iron and bolts (like to avoid that). I can imagine several ways to do it, but looking for a tried and true method before I go wasting good wood.

Any thoughts?


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## lucas.j.dunton (Feb 27, 2008)

http://www.dovetailspline.com/

I think one of the members on here sells these, but that is how that bench is made.


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## woodnthings (Jan 24, 2009)

*A challenge for sure*

Your first task will be to achieve an accurate 45 degree on both pieces. A beam saw or very large radial arm saw with a 24" swing would be ideal. Lacking access to those a circular saw with a guide may work. If you make a mark on the cut line then run the saw across using a guide you will get one of the 45 angles. If you then keep the same face up and saw from the opposite side you will get the other 45 angle. You will loose a bit in the kerf, but no big deal.. 
The tapered splines can be done by hand or with the Kehoe jig like this:
http://www.dovetailspline.com/
Like you I would not use metal on the back side, unless it's absolutely necessary. A inside wooden corner piece would be more fitting, but the splines will hold it rock solid. JMO.


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## crworld (Feb 18, 2009)

*Folded slab*

Thanks for the comments and the tip on the splines and jigs.

Guess I'll have to make a beam saw to handle some of these long 45 cuts, but I'll give the circular saw suggestion a try first. A 10 1/4 incher off ebay will get me a 2 3/4 inch deep 45 degree cut and will be ok for some of my slabs. Just a question of skill after that.

I'm thinking if I didn't want the look of the splines perpendicular to the miter, that I could use a parallel spline inside the joint as the next strongest joint...? 

Thanks again for you consideration of my question and I'll post results as I go on with the project.
CS


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## woodnthings (Jan 24, 2009)

*You could make a sled like this*

It's kinda like a beam saw, but way less expensive and pretty easy to make :yes: .... although I haven't made one.... :laughing:
The slabs can be oriented with some adjustment factor within the sled. Change the dimension to fit your application. You can use 80 - 20 aluminum off EBay and the sliding attachments. Check out this thread for an example: 
http://www.woodworkingtalk.com/f27/super-sharp-fixture-planer-blades-37958/


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## cabinetman (Jul 5, 2007)

crworld said:


> Thanks for the comments and the tip on the splines and jigs.
> 
> Guess I'll have to make a beam saw to handle some of these long 45 cuts, but I'll give the circular saw suggestion a try first. A 10 1/4 incher off ebay will get me a 2 3/4 inch deep 45 degree cut and will be ok for some of my slabs. Just a question of skill after that.
> 
> ...


You can make a good crosscut jig to make the crosscut, and to cut the 45 with an appropriate handheld circular saw.

You can make a blind spline groove to the edges of the 45. That is a joint where the actual spline stops short of exiting the stock. Once you have the crosscut, and the miter cut, make a jig that clamps to the stock positioning the router 90 degrees to the face of the 45. The jig would be flat for the base to ride on, and a short fence on the left of the plate for the router base to be registered against. Marks or stops can be placed to position the groove in its length.










 







.


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## Midlandbob (Sep 5, 2011)

Let us know if you make it work. I have made the benches and considered the 90 degree table. I wondered about cutting and holding them close then passing a router thru the joint on an angled jig to make the fit perfect.
I also considered using the tempered glass used in decking to put in a dado on the inside it might look elegant and support the top.
Good luck with the challenge.
Bob


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## J Thomas (Aug 14, 2012)

Could you employ a natural crook in the manner shipwrights use "tamarack knees"? You can find decent sized growths on apple trees.
Dowels & glue or a blind dovetail to join..
Best Luck!
..Jon..


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## crworld (Feb 18, 2009)

*Folded slab*

ok, Have taken a shot on a small maple slab that I sliced with a circular saw and put the 45's on the table saw, not quite what I envision for 3" thick slabs that will weigh a lot more, but it's a start. Homemade dovetail spline jig seems to work just fine.

Thanks again for the comments and help


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## crworld (Feb 18, 2009)

*folded table*

Test project completed. Next step is a 12' x 30" x 3" oak slab. Will have to construct a saw to make the 45 degree cuts for such big pieces. I have an old table saw that might provide the basis for a machine. Will post as I go.


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## Dominick (May 2, 2011)

That's awesome joinery there. You really pulled it off. I thought about doing a bench like that, and soon realized not. 
How is it attached underneath the slab? Just the miter and keys? What's stopping it from racking. 
Looks interesting.


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## woodnthings (Jan 24, 2009)

*I have this panel saw kit*



crworld said:


> Test project completed. Next step is a 12' x 30" x 3" oak slab. Will have to construct a saw to make the 45 degree cuts for such big pieces. I have an old table saw that might provide the basis for a machine. Will post as I go.


http://www.sawtrax.com/panel_saw_kit.html
You can use a portable circular saw in this set up OR make something similar using thinwall tubing. A large 10" Milwaukee circ saw would be good for thicker slabs.


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## rayking49 (Nov 6, 2011)

Man that looks great! I really like how it turned out. Clean joinery lines!


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## crworld (Feb 18, 2009)

*Folded Table*

Hi, I have moved on to an oak slab for the next phase of my folded table project, which has an ultimate goal of creating a large folded walnut desk. The struggle so far has been to make a long, accurate 45 degree cut in a wide, 3" thick work piece. 

The first test piece, the maple slab, is rock solid, the walnut dovetail splines and internal 1/4 birch plywood spline (in the miter) have made it really strong.

Moving along, the 12' x 30" oak slab proved too heavy for me to move alone, so I grabbed a 8' x 19" x 3" for this next phase of the project - it still weighs ~140 lbs.

I was thinking of the saw sled suggested in the post by Woodnthings and it occured to me that I already have one! The photos show how I turned over my old Skil Saw, put it on some tracks and made some nice cuts. Can use some refinement to fine tune, but it really worked great. Let me see any safety issues you see that need a remedy.

The angle came out great, put some 1/2" plywood blind splines into the joint and will add some dovetail splines to the corners next.

Thanks again for the suggestions and comments, I'll keep posting the project as it goes along.


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## crworld (Feb 18, 2009)

*folded table*

Oak slab legs folded into place with blind splines in the joint


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## Dominick (May 2, 2011)

That's cool, but are you adding a stretcher in between the legs to add stability? Like racking. 
Just wondering. 
Looks good otherwise.


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## Leatherneck (Dec 14, 2008)

inverted table saw jig .. WOW .. looks great


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## woodnthings (Jan 24, 2009)

*great idea!*

I had the same thing in mind from a previous post and discussed it with a WWT buddy back then. He had a large piece to trim at a bevel and it was great to see you actually had success with it!

My theory is when the work is too large or too heavy, move the tool, it's easier and safer. NOW you are in business.:thumbsup: No slab too large or too thick...well almost..... got a 12" Craftsman motorized saw laying around?
I actually got one (more) off Craig's List about a year ago. 

I like your dust deflector plate on the bottom, which is now the top.

Love those tables and the joinery. You are a very clever guy. :yes:


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## crworld (Feb 18, 2009)

*Folded table - racking*

The spline placed in the joint parallel to the miter seems to be pretty strong on its own. I guess it locks the base of the joint, and the dovetail splines seem to lock the top of the joint in place. My kids (and I) have jumped on this bench and it shows no flex at all, seems really rock solid. Even placed on its side and tested I think would hold until the failure point of the wood in the joint was reached. Time will tell if the joints loosen up.

At first, I was really planning to add a stretcher across, since I tend to go heavy on structural aspects, but I have backed away since it seems plenty strong and gave the look I wanted.

There will be an offset stretcher in desk build when I get there.


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## BZawat (Sep 21, 2012)

Nice. Pretty ballsy of you to flip over the portable TS lol! I bet it labored cutting those 45's. never would have thought of that.


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## Phaedrus (Jan 18, 2012)

What kind of glue are you using? Regular yellow wood glues should be fine in the splines where you have edge-grain contact, but expoxy would take better advantage of all of that surface area on the end-grain miter cuts (I think). As long as all of your joints are tightly glued and it is placed on a level surface, I can't image racking being an issue...at least in my lifetime.


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## crworld (Feb 18, 2009)

*Folded Table - glue*

Since this bench/coffee table was a test...I experimented with glue. I used yellow glue in one joint and urethane resin glue (Gorilla) glue in the other. After completing the joints, I think the glue is the minor component for holding it all together. Time will tell, but I'm thinking (and hoping) this thing will stay tight for a long while.


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## Dominick (May 2, 2011)

That came out really nice. I like the dove tails. 
Nice touch.


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