I am creating a cloak of 100 bronze leaves to hang in the woods, as the centrepiece of “The Meaning of Trees” event. It's important that the leaves catch the sunlight as the sun moves round the woodland setting. I want the leaves to glint in the light.
Bronze pieces naturally change their colour to brown and then blue over time, see left-hand picture below. In the picture below right, the leaves have just been fettled with a soft wire brush attached to an air driven pen. But they will not stay so bright and shiny for long. The technical challenge is that bronze very quickly becomes dull and tarnished, especially outside in the wind and rain.
I have sought expert advice, but the experts don’t agree! Especially on the choice between wax and lacquer. And then there’s the question of what type of wax or what type of lacquer and how many layers to do.
In my experiments I have treated some of the leaves with wax and some of the leaves with a special lacquer. I have then been putting my leaves outside to see how they change in the weather.
Here is my step-by-step method
Using Tiranti sculpture wax
Place the bronze pieces for 30 mins or so in a pickle tank (dilute sulphuric solution that is kept at a warm temperature).
rub the bronze pieces with a soft bristle brush and pumice stone powder
fettle the bronze pieces with an air driven pen fitted with a soft wire brush (chimney sweep shape)
heat the pieces with a hot air gun
apply clear wax suitable for furniture
let it cool
polish with a cloth and very soft brush
do this three times
Using car wax
One and two above
don’t heat the bronze
apply car wax e.g. Carnauba paste wax / Turtle wax
leave to form a haze
polish with cloth and soft brush
do this three times
The photo shows just one layer of wax and just over a couple of days the bronze is beginning to discolour. Though this may be attractive if an aged look was required.
Using laquer (Clear Guard lacquer satin Tiranti sculpture supplies)
wipe with solvent on a cloth to remove greasy finger marks etc.
one and two above
don’t heat the bronze
mixed 10% solvent into the clear guard lacquer. I used clear guard satin. They don’t supply a glossy finish
apply the lacquer mixture with a good quality paintbrush
allow one hour drying between coats
apply two coats
I like this effect – shiny, but the satin coat is not too shiny, with variations in colour.
I also tried applying a clear gloss lacquer, suitable for some car parts, but I think it became too shiny and brassy looking.
Click here o find out more about 'The Meaning of Trees' event.