Live Edge Coffee Table, How To Flatten A Live Edge Slab - Woodworking
In this video, I'll show you how to build a live edge coffee table, and how to flatten the live edge slab using a router flattening jig. The process is simple and does a good job of flattening a large slab like this White Oak "cookie" slab.
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Materials Used On The Live Edge Coffee Table :
- White Oak Live Edge Slab, 40" in diameter
- (2) 2x4x8 for the table base
- (1) 2x8x8 for the router jig rails
- (1) 2x4x8 for router jig rail frame
- (1) 2'x4' ½" plywood project panel for router jig sled
- 1 ¼" Screws
- 2 ½" Pocket Hole Screws
- Danish Oil
- Black Spray Paint
- Felt Furniture Pads
Tools Used On The Live Edge Coffee Table :
- 2" Infinity Tools Planer Router Bit
- DEWALT Plunge Router
- Collet Extension (which I bent)
- DEWALT Trim Router
- ¼" Up/Down Cut Spiral Bit
- SawStop ICS 3-HP Industrial Cabinet Saw
- Festool Kapex Miter Saw
- Powermatic PJ-882HH 8-Inch Jointer
- Powermatic 15HH 15-Inch Planer
- Kreg K4 Pocket Hole Jig
- MIRKA DEROS Sander
- Belt Sander
- Parallel Bar Clamps
Live Edge Coffee Table Base Cut List:
|4||Sides Leg||14"||3"||1 1/2"|
|2||Stretcher||18 1/2"||3"||1 1/2"|
|4||Top Bottom Leg||18"||3"||1 1/2"|
Live Edge Coffee Table Build Process:
The first step in this build is to make the router flattening jig. These jigs are fairly simple to make, you basically just need a sled for your router to ride on above the slab. This sled rides on two rails, one on each side of the slab.
I sized the base of the sled to be wide enough to fit the base of my router plus the widths of the side walls of the sled. I made the base out of ½” plywood, which allowed me to get more depth without having to use a collet extension on my router. Once I knew the width I needed, I ripped the plywood to width on the table saw.
For the side walls, I used two strips of ¾” plywood glued together. Since I used ½” plywood for the bottom of the sled, I wanted to make sure it was nice and stiff, which is the reason I went with double layered plywood for the sides. I cut the sides to length at the miter saw using some offcuts of plywood I had on hand.
I glued the pieces together, added a few brad nails to hold them in place, and then added some 1 ¼” screws to tighten everything up.
With the sides done, I added glue to the bottom of the sides, clamped them to the base, and then added countersunk screws from the underside of the sled. It is really important that these screws are well below the surface, as you don’t want them interfering with the sled riding on the rails.
Next, I needed to cut out the channel for the router bit. I marked the center of the base and then used a 2” Forstner bit to drill a hole on each side.
Once the holes were drilled, I cut out the section between the holes using a jig saw. This doesn’t need to be precise, as the router bit will be used to finish up the channel later on.
To keep the sled from falling off the rails, I added some stops on the underside of the sled. These are just scraps of ¾” plywood, and I attached them using pocket screws.
For the rails, I used a 2x8 and ripped it to rough width on the table saw. The width of your rails will depend on the thickness of your slab. The slab I’m flattening in this build is almost 6 inches thick, so I cut the rails to 6 ½” wide.
After ripping the rails to rough width at the table saw, I ran that edge over the jointer to ensure it was perfectly flat. If you don’t have a jointer, you could either use a hand plane to flatten this edge or just hope that your table saw left you with a straight enough edge. You could also use plywood for the rails, as the factory edge on plywood is going to be straight enough for this purpose.
Once I had jointed one edge, I ripped the rails to final width at the table saw.
With the sled finished, I headed over to my buddy Ryan’s shop, where we’d be flattening and finishing the slab.
The router bit I’m using to flatten this slab is this monster of a bit from Infinity Tools. It has a 2” cutting diameter, 1” cutting depth, and absolutely chewed through the end grain White Oak on this slab. I’ll have a link to the bit in the video description if you want to check it out, I highly recommend it for any router flattening project.
Before flattening, I shimmed up the slab so that any rocking was removed, and then we used the router to clean up the channel in the bottom of the sled. We noticed that the rails were a little unstable, so we attached a 2x4 between each end of the rails and this really helped to stabilize things.
With everything setup, I set the depth of the router to take off about ¼” and started flattening. I made the initial pass standing in the direct path of all of the chips coming off the router, and ended up tearing up my shins.
On the second pass, I moved to one side of the jig, and Ryan and I passed the router back and forth. This worked much better. We needed to make quite a few passes on the bottom of the slab to get it flat, but once it was, we flipped it over to work on the top.
Before flattening the top of the slab, I needed to rip off about an inch from each of the rails, so that the bit could get enough depth to fully flatten the top.
We did try using a collet extension to help give the bit depth, but it ended up getting bent when the bit caught during one of the passes.
Once the sled was back in business, we got to flattening the top of the slab. This only took one pass, but we did get a little impatient and were probably taking off about ½” of depth on this pass. Amazingly enough, this router and bit combo didn’t have any trouble and left a super clean surface.
With the slab flattened, we needed to clean up the absolutely ridiculous about of sawdust before moving on. If you’re going to flatten a slab like this, you absolutely need to wear a respirator. The dust this process produced was insane. We filled four 33 gallon trash bags full of dust.
Once the shop was a little cleaner, we started cleaning up the edges of the slab. There was quite a bit of rotten sapwood and bark on the edges of the slab, and I Just knocked these pieces off with a chisel and mallet. After removing all of the loose pieces, Ryan cleaned up the edge using a belt sander.
As you might have noticed, this slab has a pretty massive crack running down the center. To stabilize the slab, we decided to add a bow tie key, sometimes called a Dutchman or butterfly.
This was actually my first time installing a bow tie, and I’m really happy with the way it turned out. I cut the bow tie out of a scrap piece of Walnut off camera using my bandsaw and then traced the outline of the bow tie onto the top of the slab.
Next, I used a trim router with a ¼” up/down cut spiral bit to clear out most of the waste. I routed out the pocket in two passes, as the bow tie was about 1” thick. I made sure to stay clear of my lines and also set my final depth on the router to leave about ⅛” of the bowtie protruding.
With the majority of the waste removed, I cleaned up the walls of the pocket using a 1” chisel. Since I got so close to my lines with the router, I could chisel right to my line.
After dry fitting the bow tie, I added glue and pounded the bow tie home using a mallet.
Once the glue had dried, I came back with a plane to flush up the bow tie. I only brought my smoothing plane with me to Ryan’s shop, which probably wasn’t the best choice, but it still only took a few minutes to flush it up.
Next, Ryan sanded the slab, first using a belt sander to remove any router marks and then switching to a random orbit sander.
Once we were finished sanding, it was time to apply finish. We went with a simple Danish oil finish, as we wanted the natural look of the wood to really show through. We applied two coats, letting the oil soak into the wood for about 30 minutes between coats.
With the slab done, it was time to build the base. I actually built the base in my shop before heading over to Ryan’s, since we had limited time there. For the base, I kept it really simple and just made a modern looking base using 2x4s.
First, I cut the pieces to length. A cut list is available at the top of this post, but you will need to adjust the sizing to fit your slab.
After cutting the pieces to length, I ran them through my planer just to clean them up. This is a totally optional step and you could skip it if you don’t have a planer.
With the faces nice and clean, I decided to rip off the roundover on each edge of the 2x4s, which I did on the table saw. On the first pass, I set the fence to 3 ¼” and on the second pass, I set the fence to 3”. This leaves you with a nice, square piece.
To assemble the base, I used pocket holes. The way the base is designed makes it so that no pocket holes are visible in the final piece, so you don’t have to fill these holes later.
I did run into one issue during assembly. I didn’t think about the fact that planing the 2x4s would make the standard 2 ½” pocket screws too long, so I had to switch to regular 2” pan head screws. These ended up working fine, but it’s something to keep in mind.
To further reinforce each corner, I added one Powerhead screw to each corner, using FastCap’s Flushmount drill bit to countersink the screws.
Next, I needed to attach the stretchers that connected the legs to each other. I centered the stretchers on the legs and then clamped them in place, making sure I was on a flat surface, my table saw in this case.
With the stretcher clamped in place, I added 2 ½” pocket screws to secure the stretcher in place and I repeated this step for the other stretcher.
After assembly, I sanded the base thoroughly with 120 grit then 180 grit sandpaper.
For the finish, I added a few coats of black spray paint. I really like how the grain pattern shows through on the base, I think it gives it an awesome textured look.
To attach the base to the slab, I used a few 2 ½” screws, making sure to slightly widen the holes in the base to allow for wood movement. Finally, I added some felt pads to the bottom of the base off camera, and the table was done