Router Jig Makes Quick Work Of Flattening Irregular Shaped Wood

slab flattener

[Nick Offerman] is a pretty serious wood worker. He likes to make crazy stuff including organic looking tables out of huge chunks of wood. Clearly, the wood doesn’t come out of the ground shaped like the above photo, it has to be intensely worked. [Nick] doesn’t have a huge saw or belt sander that can handle these massive blocks of wood so he built something that could. It’s a jig that allows him to use a standard wood router to shave each side down flat.

The process starts by taking a piece of tree trunk and roughing it into shape with a chainsaw. Once it is flat enough to not roll around, it’s put into a large jig with 4 posts. Horizontal beams are clamped to the posts and support a wooden tray which a wood router can slide back and forth in. The router’s cutting bit sticks out the bottom of the tray and slowly nibbles the surface flat. Once one side is flat, the block is rotated and the flat side is used as a reference to make all the other sides square to the first. After flattening, sanding and finishing the block results in a pretty sweet piece of functional artwork.

27 thoughts on “Router Jig Makes Quick Work Of Flattening Irregular Shaped Wood

  1. I would love to make super-chunky wooden things. Does anyone know the details of seasoning wood in such thickness? Are there species of tree or techniques you could use to get away with no seasoning or minimal seasoning? It would be nice not to have to wait 2 years while the wood seasons to get started.

    1. No idea on seasoning such huge chunks but its often good to rough out the design, let it warp and then go to the final dimensions. If you wait before roughing out the wood gets really tough. Also removing excess wood and bark will speed the drying process.

      1. For pieces that big, there are very few shortcuts one can take.
        It’s a little bit like the signs one used to see in auto mechanics’ shops: “quick, cheap, or right – pick two.”

        Trunk sized pieces will split radially if you try to dry them too quickly; they’re best seasoned for a year or two with the bark on. Exceptions to this are *very* expensive resinous hardwoods which are hard to find in such sizes.

    2. Find a company that does timber frame houses. You may be able to get then to dry things for you, or sell you some dry timbers. A quick google from that recommended Vacuum and/or RF kilns which will dry 8×8’s inside of a week. If you’re air drying it’s gonna be longer than 2 years. Conventional wisdom is a year per inch of thickness for dimension lumber.

    1. There was a hack a week or two ago about a chainsaw mortising jig and they ran into problems w/ bar flex. Also because they don’t leave a good finish. Even purpose built bandsaws leave a rough surface. You could certainly use either method to rough out a workpiece, which is what [Nick] does. If you want a furniture grade finish you’re going to have to use something more refined at some point though. The sheer size of the workpiece probably precludes the use of a power jointer or surfacing machine (ones that would fit it cost $$$) so you’re left with the method described in this article or using a hand plane.

  2. Thanks for clearing that up! I’ve seen amazing cross-section log tables over the years and marveled at the chisel skills I assumed such projects took. Now I know the secret (and a new use for my router).

  3. Pretty sure this was a published article in FineWoodworking about making live edged slabs for tables. Looked to be the same design and everything, and I seem to remember it being published about 3 years ago.

    1. Edit- the link was broken for me at work, but on my phone it shows it does indeed go to finewoodworking. The date published (2015) threw me off. I thought someone was trying to take the original publishers work.

  4. Impressive! Cannot wait for the next idea. Given a free hand, no telling what you will create! The law of diminishing returns is at work here – new technology equates to startling new creations – old technology equates to few new creations. You can go to my woodworkingbuddy blog and see some projects.
    Kind regards

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