Thicknessing and planing wide hardwood boards

Question

I have some 600x1200mm (24"x47") hardwood (iroko) boards at just over 27mm (>1") thick that used to be old work tops from a school.

I would like to clean them and use them for a kitchen worktop as it's beautiful and robust wood.

The issue is that they currently have bowing and cupping and I don't have a thicknesser and certainly could not afford one that would have the capacity to handle such a wide piece of hardwood.

The options, as far as I can tell, to me are:

1. attempt to plane and thickness the entire board by hand using hand planes.
   • Downsides here are that it'd take forever and I am not that confident in my skills to be able to do this to a high standard.
2. Pony up and pay a professional company to plane and thickness the entire board
   • downside here would be cost and potentially losing a lot of material.
3. Dejoint the board using a circular saw & guide so they are narrower, then plane and thickness those narrow boards - either by hand or with a more easily available thicknesses, rejoint those boards together.
   • My fear with this approach is that I won't be able to get the joints spot on and they'll be a very obvious gap along its length.
   • Will lose some material off the edges.
   • Pros are that I lose less material off the top face.

Are there any other options open to me?

Answer 1

Are there any other options open to me?

There is one other option that you didn't mention. You can build a "router sled" to flatten wide boards.

This is basically two rails on either side of the board with a narrow platform that slides along them. A router rides on the platform, and the platform has a slot cut through it that the bit projects through to contact the work piece. The router is then passed over the entire surface of the board, flattening it.

Start by putting your work piece on a large surface or floor. Stabilize it with shims or wedges so that it doesn't rock or flex.

Then you'll need two flat, stable rails at least a foot longer than your work piece. These have to be thick enough to support the weight of the sled with minimal flexing. Steel beams or square tubing work well if you don't have a good way of jointing long material. Place them on the floor to either side of the work piece with the jointed edges facing up. Block or shim them up so that they're above the surface of the work piece, then make sure there is no twist in them by running two taut strings from corner to corner. The strings should just touch in the middle.

Then make a platform for the router to run on. This should have rails running along the top to give it enough strength to not sag when the router is in the center. These rails can also serve to keep the router "captive" so it only moves from side to side. Plunge the router through the bottom to cut the slot for the bit to project through.

I don't actually recommend this option for you, though. Since these are already glued-up panels and not slabs I'd personally rip the panels apart and re-glue them. This will save the most material in the long run, and only requires a table saw and some clamps. The narrower boards can be jointed by hand or on much more common equipment.