Thursday, October 21, 2010

TGIF - Time to get plastered...

Our local plaster specialist, Plaster Supplies in Hamilton, was very helpful, and is able to custom make everything we need for Willowbrook. A veteran plasterer and designer himself, he was very excited about the opportunity to work on a period home, and was able to show us some of the 150 year old cornice moldings that he had in storage, which he hasn't had any call to use - until now! They are also going to make the 10 foot plaster ceiling dome for the foyer from our drawings. I imagine that it will end up looking something like the one above.

They had a lot of other nice Georgian period ceiling roses and plaster details...

The ceiling roundel above will be used in the Chatsworth Suite.
The roundel below will be used in the Blenheim Suite

We will use this Adams style cornice in the Wedgwood Room...

With matching ceiling roundel...

And matching fireplace surround...

We plan to use the bottom of the pediments pictured above over the door inside the Blenheim suite (c.f. the Chinese Room in Claydon House), the third from the top for the Chatsworth suite,.
We will use the second from the bottom for quite a few other pediments.

The pediments for the main foyer will be made out of the same pattern as the cornicing for the foyer, shown below...

We will also use one of these friezes to run up the staircase below the balusters, and continue around the floor, similar to the idea featured in the second picture below...

We have even found some period vent grills / covers, to go over the air-conditioning ducting...

All pictures on light blue background are from Ceiling Panels Australia's catalogue. Our local plasterer imports from them directly.

There are other plaster suppliers in NZ who also have some good cornices and roundels:



Whilst we were poking around the plasterer's workshop looking at the antique cornicing, we noticed one that seemed to be carved out of wood. It had a lovely mahogany finish to it, and the detailing was quite intricate. Actually, it turned out to be made out of plaster, like the others, but had been coated in shellac, to look just like mahogany. It was very well done. For both the studies, and the billiard room, we were going to have carved mahogany panels, but now plan on having a mixture of wood and shellaced plaster detailing. The production time is significantly shorter, and it can be done for a fraction of the cost.

Shellac is a resin secreted by the female lac bug, Laccifer (Tachardia) lacca Kerr, which is found on trees in the forests of India and Thailand. The bug forms a tunnel-like tube as it traverses the branches of tree. Though these tunnels are sometimes referred to as cocoons, they are not literally cocoons. This insect is in the same family as the insect from which cochineal is obtained.

Above: Lac Bug (beetle)

It is processed and sold as dry flakes, which are dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood varnish. Shellac functions as a tough all-natural primer, sealer, tanin, odour and stain blocker. Shellac was once used in electrical applications as it possesses good insultation qualities and it seals out moisture. Gramaphone discs were also made of it during the pre-1950s, 78-rpm recording era.

Above: Shellac flakes in differing shades

The least coloured shellac is produced when the insects are parasitic upon the kursum tree, (Schleichera trijuga). The raw shellac, which contains bark shavings and lac bug parts, is placed in canvas tubes (much like long stockings) and heated over a fire. This causes the shellac to liquefy, and it seeps out of the canvas leaving the bark and bug parts behind. The thick sticky shellac is then dried into a flat sheet and broken up into flakes. It is then mixes it with denatured alcohol on-site a few days prior to use in order to dissolve the flakes and make liquid shellac.

Shellac is often the only historically appropriate finish for early 20th-century hardwood floor, wall and ceiling paneling. From the time it replaced oil and wax finishes in the 1800s, shellac was the dominant wood finish in the western world until it was replaced by nitrocellulose lacquer in the 1920s and 1930s.

Multiple thin layers of shellac produce a significantly better end result than a few thick layers—thick layers of shellac do not adhere to the wood or plaster well, and thus can be peeled off with relative ease; in addition, thick shellac will fill in (and thus ruin) carved designs in wood and other substrates.

Shellac naturally dries to a high-gloss sheen. For applications where a flatter, more matte finish is desired, products containing amorphous silica, such as "Shellac Flat," may be added to the dissolved shellac.

Shellac naturally contains a small amount of wax (3%-5% by volume), which comes from the lac bug. In some preparations, this wax is removed (the resulting product being called "dewaxed shellac"). This is done for applications where the shellac will be coated with something else (such as paint or varnish), so that the topcoat will be able to stick. Waxy (non-dewaxed) shellac appears milky in liquid form, but dries clear.

The finished product looks something like this...


  1. How exciting be able to begin ordering fittings. So glad your local plaster man did not disappoint! I remember when my husband installed a ceiling rose in an old villa we owned in Napier. It was quite comical (poor hubby is not a born handy-man) but it looked so lovely once it was up and painted with chandelier in situ.
    I'm enjoying being able to go on this journey with you. Looking forward to more great posts :o)

  2. Bravo. All of the plastering work that we have done in restoring Darlington House has been done using traditional methods. I can attest to the fact that there is really nothing like "real" plaster, vs. skim coated drywall and polystyrene moldings. And yes, shellac is far preferable to the more modern, petroleum-based polyurethane. Good work!

  3. How wonderful to have found such a passionate local Supplier David! Everything you've chosen looks perfect.
    Millie ^_^


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