Wednesday, 21 March 2018

Building up the frame for the inner decorative panel

This is the inner decorative panel of the table I'm building.

The beautiful tiger striped wood is spalted beech. This is common beech with natural discolouration caused by fungal colonisation of fallen logs.
This post is about how these were cut 

Raw materials for the frame - Victorian hardwood...

The frame has four rails. These were reclaimed from this lovely old door. It is a Victorian door from a specimen cabinet from the Natural History Museum.

The door frame rails were sawn off

These were OK,  but they were too thick, so they were ripped down into separate thinnere planks.

To give these...

You can see the innards of the door joints...

These were plane to a uniform thickness using the disturbingly effective planer/thicknesser (aka The Beast)


The thicknesser leaves the wood smooth as glass.

These were cut to length to go within the existing frame.

The corner joint were then cut as mitred lap joints.

They work like this...

Actually after sawing you get rough faces like this, which need cleaning using the rebate plane

Much better!

The planks of spalted beech were jointed into the frame using a combo of cut rebates and some inserted tenons from offcuts

Those tenons might look neat,  but they started with glued in offcuts like this...

and this


which were sawn off then trimmed neat with the rebate plane/


Sunday, 18 March 2018

Spalted beech planks from logs

This lovely stuff is spalted beech. The beautiful veining is created by fungal colonisation of the fallen logs. As the fungus grows through the log, it changes its colour. I believe the very dark regions are the boundaries of a fungal colony and that there may be more than one type of fungus in different parts of the log.

Apparently spalting can occur in various woods, but it is most common in beech.

These slices are the beginnings of planks, I made last Autumn.

The planks were cut from these logs. You can see the white bloom of fungus on the end.

Here is one of the logs in my shed. I'm just about to clamp it into the bench vice.

I don't have a bandsaw for ripping logs, so I cut these planks by eye, using a chainsaw. Note the faceguard, ear defenders, gloves and leather apron for safety (although bare arms is possibly not the recommended protection for using a chainsaw - don't try this at home, kids!)

The fungus highlights the separate heartwood (inner) and sapwood (outer)

I use this cheapo electric chainsaw from Screwfix. Nothing fancy, but it is good enough for the occasional use I give it. Being electric, you can us it in the shed without worrying about fumes or storing petrol etc.

When cut this log had been standing in the woods for at least a year, possibly longer. It was very wet.

The cut planks were stack with spacers and left to season outside in one of the outbuildings.

Tuesday, 13 March 2018

Clamping the base frame

After a few weeks of making all the table top pieces, it is time to start gluing them together.

This is the bit where you need to be sure everything fits perfectly (well, as perfectly as your preferences tolerate)

You also need to take it apart to glue. For this reason, you also need to mark how each part connects to the others or you'll glue the wrong bits together.

Here's the base...

This is being clamped together after gluing...

Before gluing all the joints were trimmed to make the mitres fit as snugly as possible. Then the farne was rechecked to make sure the corners were stil square. They were!

So, as the joints were snug and square, the whole thing was taken apart to glue it. You can't really see it here, but each base board and all four rails are numbered so it is easy to see where they fit together.

The boards are pretty rigid (they are blockboard library shelves), but to make the base really solid and hold together, I fitted two 10mm dowels between each butt joint so the planks would form one big board when glued and be super strong.

The router makes a great clean hole and its guide rail and depth guide mean they are all consistent.

Just these two dowels makes the joint strong enough to standup easily.

This is all that is holding that together. the dowels fit snugly, so they are tight.

You can see one of the numbers used to ensure the disassembled boards went back in the right order later. Here, I am testing they all fit.

The numbers 3 and 4 are clear here.

For extra strength, I roughed up the grain on the end of the planks, so the glue would have something to bind into. I used a riffler (rough sculptors rasp) for this.

The dowel being glued in.

The plank rebates being glued into the four mitred edge rails.

Finally the whole lot was glued up and put together, then clamped.
To start with 2 sash cramps were fixed across each short rail. The tenons were on the end of these rails and the cramps held tenons firmly into the mortices in the long rails.

Clamping can shift the angles, but the joints turned out to be pretty square. The angles were still dead square. Quiet mental pats on my back.

But it is not just shear that can affect the integrity of the joint. They can also be slightly twisted so the edges don't line up. For this reason the corners were clamped with wooden planks to keep the mitre edges aligned horizontal while the glue set.

I used whatever plank pieces were lying around.



To prevent twisting, I put the whole thing on the floor, which was the largest flat area available.
This was left for about 36 hours...