Repairing a Victorian Balloon Back Chair

I bought a set of four of these chairs on a whim at an auction in the late 1980's. I was attending to buy another piece of furniture and ended up taking these home as well!

The chairs are made from Australian Red Cedar (toona ciliata) in about 1880. Australian Red Cedar (ARC) was the most sought after native timber in Australia during the 19th century. Most other Australian timber species were extremely difficult for 19th century cabinet and furniture makers to work with. ARC is a soft and easy timber to work with the hand tools that would have been available to craftsmen of that era.

Because ARC is so easy to work with; the trees were almost hunted to extinction in the 19th century.

While beautiful to look at, the timber is really not very suitable for chair construction because of its softness. Hence ARC chairs are relatively rare in a usable form; let alone a set of four. The Victorian balloon and kidney back styles of chairs are particularly unsuitable for this timber and you will see why in upcoming photos.

Looking back on it, this was not my best purchase. Victorian antiques are very unfashionable these days and the cost of sending these to a professional restorer would now far outstrip their value individually or as a set.

So in the interest of saving these from the fire, I decided to repair them myself.

Step 1: Balloon Back Chair Construction

You can see in the first photo the dowel hole exposed in the chair back rail balloon top.

This is the only practical method that was available to 19th century craftsmen to join a balloon top of a chair to the back rails of the chair. You can also see in the subsequent photographs that this is not this chair's first brush with the restorer!

The dowel runs parallel with the grain of the back rail and this is a structurally weak design. I also own a couple of kidney back chairs of the same era made in Rosewood. While the kidney back chairs no doubt share the same structural design flaws as the balloon back chairs, the kidney back chairs have survived undamaged since the 1880's. This could partly be because they had an easier life; but the timber is also much better suited to this construction design.

Step 2: Removing the Compromised Material

As you saw, the backs of the chairs had been repaired (badly) several times in the past. While I understand the need to conserve as much original material as possible in a restoration; these chairs are not in a museum. Nor are they ever likely to be. They have to be usable as a chair.

So the first step was to cut away all of the compromised chair back rail and (just) into undamaged timber.

I used a large tenon saw to cut a flat section while conserving as much of the original rail as possible. I

One unexpected find was a disguised wood screw. Unfortunately, I found that with my tenon saw. In hindsight I should have used the metal detector that I own to search for hidden fasteners. I just wasn't expecting them to be there so I didn't look.

I used a hacksaw to saw through the screw then completed the cut with the tenon saw. To extract the screw, I cut a slot in the screw with a Dremel cut-off tool and backed out the screw with a standard screwdriver.

I now planed this saw cut dead flat using a block plane and checking with a metal ruler diagonally, vertically, and laterally until I was certain it was flat.

Step 3: Replacing the Compromised Timber

I had acquired some new ARC pieces from a timber merchant and cut blocks larger than the removed areas to replace the compromised timber.

I glued the blocks in place using hot hide glue (aka animal glue, bone glue). Hot hide glue (HHG) is historically correct but there is another -- more important -- reason I used HHG. HHG has a property that no modern glue (that I am aware of) has.

You can glue a block like this without clamps. You will see it referred to as a rubbed glue joint. You can only do this with heated raw untreated hide glue. The preserved hide glues that you can use at room temperature like Titebond's product cannot do this. Don't get me wrong. Titebond's product is a great product but it does not work for this application.

What is happening is that when the two surfaces are rubbed together, the glue cools and sets. Quickly! If you mess it up though, it is easily undone with the application of heat or pure alcohol injected into the joint.

This is the same reason that HHG is still used by luthiers in the construction of wooden musical instruments. It is reversible and you can get a join with good surface preparation and little pressure.

Step 4: Shaping the New Timber

I now gently but firmly clamped the chair to the workbench. I made a template of the mating surfaces for the balloon tops and drew that on the mating surfaces on the back chair rails. That was all that is involved in marking out.

“The sculpture is already complete within the marble block, before I start my work. It is already there, I just have to chisel away the superfluous material.” ― Michelangelo Buonarroti

Using the sage words of Michelangelo, I now started removing the wood that was not part of the chair...

For this task I used a drawknife, chisels, block planes, spokeshaves, rasps, and abrasives. Just keep working until the curves are faired. Use your sense of touch as a guide. It is perhaps counterintuitive; but your sense of touch can be more revealing than your eyes. Eyes can be deceived by lighting and your position relative to a non-obvious imperfection.

That said, it is pretty easy to visually determine when you are nearly finished. You can see in the second and third photos the join that is exposed when the superfluous material has been removed.

When you can't see or feel an imperfection; you are finished!

I did need to fair in the back rails to the newly fitted balloon tops which did mean that some original material need to be removed.

Step 5: Broken Turned Leg

In the not too distant past; this particular chair came off second best in an altercation with an obstreperous adolescent...

The adolescent got over it. The chair, not so much...

Step 6: Repairing the Broken Leg

My first thought was to make a whole new leg. However, my skills as a woodturner are best described as: developing.

This was (and still is) beyond my ability as a woodturner. So initially, I thought I might be able to get away with a repair using a large dowel. While the chair was usable (i.e. it didn't wobble; too much...) it was far from ideal.

Making a new leg also means the loss of original material that arguably was not necessary.

I now sawed off the cove section of the leg to get dead flat surfaces on both pieces of the leg removing the whole cove section below the large bead.

Step 7: Replacing the Damaged Material

In the previous step, you saw in the photos the compromised timber in the leg. I removed the compromised wood and I drilled out the dowel I had added in my initial repair.

I now filled the cavity with polyester resin so that I could drill a large dowel hole.

I first of all found the centre of the leg using a centring head on my Starrett combination square. That is shown in the second photo in the last step. I drilled a pilot hole to guide the bit. Then I drilled out the mortise with a brace and bit on both pieces of the leg. I drilled the mortise slightly deeper than the tenon that would be occupying it to trap excess glue.

As you can see in the second photo, hardly any of the polyester resin is left after drilling the mortise. I'm not concerned about this as it will never be seen and the material will add to the structural integrity of the leg.

In the third photo, you can see the large turned tenon on the replacement piece. What is difficult to see is that I undercut the tenon shoulder to make sure I get a snug external fit and to trap any escaped glue. A tenon shoulder adds little if anything to the strength anyway.

I now glued the leg together. I did not use hide glue in this case. I used epoxy. I figured that I had already used polyester resin and if this ever needs repairing again in the future, it will mean replacing the whole leg anyway.

Step 8: Finishing

I first of all used a sealing coat of thinned hot hide glue. You will also see this referred to as glue sizing. This not only sealed the timber but also builds up and fills pores in the timber.

I now sanded back the sizing and applied the first coats of button lac shellac. This is the state of the chairs shown in the first photo. The chair on the left is the chair with the repaired leg. You can just make it out because of the colour differences between the old and new timber.

The chair on the right more clearly shows the difference in colour between the new and old timber. That is a new balloon back. That chair also had a meeting with the aforementioned adolescent... That top was so shattered it was beyond repair. Creation of that was long before I started documenting this repair.

To match the colours, I used Feast-Watson Prooftint spirit based stains added directly to the button lac shellac until I got closest to the original finish colour. I have not attempted to refinish the chairs in their entirety. I brushed on the tinted shellac on the new work and blended it in to the old finish. I then touched up any exposed timber from 150 years of use to disguise the wear without overdoing it.

I then applied beeswax over the entire piece with 0000 steel wool to even out the sheen over the whole chair, walked away and made a nice cup of tea, came back and buffed the chair with a soft cloth.