Tuesday, 9 September 2014

Garden Gate Project - Part 7 - Tongue and Groove boards

The tongue and groove boards were made next. To do this some 6/4 oak was roughly cut to width. Then each of these boards had one face cleaned up and an adjacent face jointed at the jointer. Then, using a wider blade on the bandsaw, each board was carefully resawn. This produced two boards of roughly 18mm thick (just under 3/4"). Then each board was run through the thickness planer to finish at a hair over 15mm (just less than 5/8") thick.
Resawing some 6/4 oak

On my original design there are actually 2 sets of boards to produce a pleasing design. They were to be alternately spaced narrow-wide-narrow. However on reflection there was a lot of waste produced with this design and I only had a limited amount of stock. It was decided to make equal width pieces.

The end boards have to be custom made to fit. One of those boards has a tongue and a rabbet. The other has a groove and a rabbet.

Original design showing
T&G boards with alternate width boards
and differing end boards

Using a Trend tongue and groove router bit on the router table a tongue was machined in one edge and a groove in the other face. This particular T&G'r produces straight cuts without a chamfer so another pass through the router table with a chamfering bit installed was used to machine the decorative chamfer.

Initial batches made with one cutter to
produce the groove
The process is first of all to remove one cutter from the set and use the assembly to cut a groove in one of the edges. This was repeated on every board in the set.

Then the 2nd cutter is added to the assembly with a series of precision spacing washers. The more washers that are added the tighter the eventual tongue and groove joint - adding washers increases the thickness of the tongue. All the boards were run through the cutter assembly to produce the tongues.

Each end board was cut to width and either had a tongue or groove cut into it. These were put to one side until the glue up of the stile and cross members will be done. Ultimately a rabbet will be cut in each of these end sections when the width of each board is determined.
Another view of a smoothing plane!

Then using a smoothing plane each board had any remaining milling marks removed. The final process on the boards was to cut the chamfers. I used a chamfering bit without a bearing to do this. Just running the boards against the router table fence enabled this. Moving the fence to do the chamfers on the shoulders of the tongue was also possible this way.

Chamfering bit cutting the chamfers
 Commercially a spindle moulder (shaper) would be used to produce the T&G boards in one pass. But as I don't have one the router table was used. Several passes and tool changes later a big pile of T&G boards were made. Only have to cut them to length now.

A pile of T&G

I will try and pick out any bookmatched or
pleasing grains before
final assembly.

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