Tutorial: How to make the mold for the curvy legs on the little table

I received several requests to show how to make the mold to create the bent laminations that became the curvy legs on a small table I built recently. Get some coffee, and enjoy!

Background:

It starts with a full-size drawing on a piece of 1/4-inch plywood – doing so allows you to adjust the arch radius, etc.:

Laying out the curves for the full-size drawing was interesting – but I found an easy way to zero in on the trammel length I would need. First, large calipers, to get the curves to look “right”:

Then I made a simple trammel with a hole large enough to allow the pencil tip draw two lines, the rough outline of the leg and stretcher thickness:

Using the trammel set for the radius in the full-size drawing, I drew the curves on a piece of 1/2″ thick MDF, and cut the curve on the band saw – THIS will become the “master”, from which all curves will derive:

Before continuing, it was necessary to smooth the edges, to finish the MDF boards with these “master” curves – I made a flexible sanding block, and sanded until happy with the curvature:

The other side of the master mold receives the same treatment:

After transferring the smooth outlines to 3/4″ MDF, I cut close to the line, and used a pattern router bit to make exact duplicates of the “master” curves:

The first set of curves on the 3/4-inch MDF becomes the pattern from which all others are made. It took several copies to make the mold to create the curves, but I was finally ready to use the mold – here is one-half of the mold, as I prepare to apply cork and tape over the cork – each new piece is screwed on to the previous one, to keep all pieces perfectly aligned – they are stacked and screwed to the previous one, then the edge is smoothed at the router table, until the desired width is obtained:

Cork is required to smooth the slightest imperfections in the curve:

Pressure is applied to smooth the glued cork on the mold halves:

Tape is then applied on top of the cork, to allow the glue to release from the mold without damaging either the mold or the work piece:

Now that the mold halves are done, it is time to resaw the pieces to be laminated:

Mix, and apply Unibond 800 on the surfaces to be laminated – this glue has a long open time, which makes very nice for this, and for veneering applications:

NOW is the time to use the mold simply insert the pieces that will become the bent lamination:

Allow the glue to cure under clamp pressure, and remove from the mold after allowing the glue to cure overnight:

After cleaning one edge, and maybe even running one edge over the jointer blades, clean up the other edge on the band saw:

It will be necessary to use a block plane (or YOUR favorite tool) to do a final clean-up of the edges:

Cleaning up the edges.

Thanks for staying with me for the entire process – enjoy! And please let me know if I goofed up something in the process.

— Al Navas