Kumiko Woodworking

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Duration: 7:15

Kumiko is a beautiful Japanese technique developed in 600-700 AD that involves assembling thin wooden pieces without the use of nails. Pieces are grooved, punched and mortised before being individually fitted using a plane, saw, chisel and other tools for fine adjustments. Steve Rothwell has been doing Kumiko for quite some time and joined us in the shop to show us his techniques.

The joinery

Steve’s work is full of cross-halving joints, all of them hand-cut. He cuts a small slot, only .004” of an inch narrower than the material he’s working with, and friction fits the parts together.

Gotta know the angle

Parts that butt together internally have angles cut on the ends that match the internal angles of the work. Steve finesses the angles with a hand plane and shop-made jig, again working in very small fractions of an inch and fractions of angles to get the fit right.

Bowed work

Some of Steve’s panels have bowed parts in them. He creates these by steam bending the parts, in addition to cutting angles on the ends of the bowed parts that allow them to seat in the frame.

Producing the pieces

Steve mentions hand ripping the thin pieces he needs, then talks about switching to a table saw for the cuts. Another approach would be to use the Bridge City hand plane with skids that allows planing parts to uniform thickness or sanding the parts to thickness with a drum sander.

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3 Responses to “Kumiko Woodworking”

  1. Rodney
    Rodney

    Wow wow wow. Thank you George for introducing Steve and his Kumiko. So very precise – I love it. I can see its use in furniture and cabinet doors, screens and just decoration about my house. Can you do a follow up video about how he does this stuff and watch Steve produce some peices?
    This has really tripped my trigger! Thanks again! Rodney from Western Australia.

    Reply
  2. Michael D'Amico
    Michael D'Amico

    As maybe an addendum to the Kumiko video, could Steve actually show how he cuts, trims, and assembles a portion of one of the projects shown? For instance, how does he apply glue to the pieces (or does he use glue at all?)

    Reply
    • Customer Service
      Customer Service

      Hello Michael,

      Great suggestion; thanks! We will add this to our list of considerations for future content.

      If you have any other questions, please chat, email, or call Customer Service. 

      Sincerely,
      Sarah
      Wood Workers Guild of America Video Membership

      Reply