In the world of gilding, oil gilding is the easiest process of all. Especially when using pure goldleaf.
In theory, you can oil-gild any object that you can paint, but it is especially true when wanting to gild
a metal object. There is a real satisfaction in turning a base metal into gold, a touch of alchemy and magic almost.
Oil gilded metal is also suitable to be completed outside in the elements,
or in an area with a damp atmosphere. It has adorned metalwork and structures for thousands of years outside.
The following is a demonstration on how to oil gild a small metal object (for the purpose of this exercise, a cast iron moulding).
The process for gilding any kind of metal is the same, although you should thoroughly
prime the metal first in whatever is appropriate. When gilding cast iron for instance, the metal should be treated with a rust inhibitor, such as a red oxide primer.
This object has been treated with a black primer specifically for cast iron, from Rustoleum, a brand of paints I find most excellent.
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For this exercise, you will need the following equipment:
A good quality brush to apply gilding size
3-hour gilders size (oil is used in this example. You can use another size if you prefer)
Gilders tip (squirrel hair)
Gilders mop (squirrel hair)
A book of gold leaf
A small metal object
First, as stated, you will need to prepare the object in question. Although anything can be gilded, you must ensure that the object is in a sound condition.
Ensure that the surface is clean, dry and free from grease. Remove any defects, rust or flaky paint and residue. Clean in warm soapy water if necessary and allow to dry.
Metal that can rust should be primed with a 'red oxide primer' (or similar) and metals that do not rust should be treated with what is known as a 'special
metals primer'. Apply one or two coats of primer and allow to dry overnight. You can actually gild directly onto bare metal if that is your desire, although the
finish will not last as long, and the item shouldn't be put outside. The process is the same, just ensure the metal is clean and dry, and skip to the sizing stage.
Once the primer has dried overnight (if applied) lightly sand to remove any debris that has settled on the paint as it dried. Wipe down with a damp cloth
and allow to dry again. It must be noted, that any bits, cracks or contaminants on the surface WILL show up through the gold, so good preparation, sanding
and priming is really essential for a good finish.
Now, once your piece is ready, you will need to apply a single coat of 'gilders size' to the surface. For this exercise I have opted to you use a
Charbonnel 3-hour clear size. The time means that after application, gold is applied up to three hours later. For a beginner, around two and a half
hours is sufficient, but the more experienced you get, the longer you can leave the size before applying the gold.
The size should be applied with a good quality synthetic bristle brush. You will want a thin and even coat. If the size is a little too thick, or sludgy,
you can add a few drops of white spirit to the size, to aid with the flow. However, this will affect the drying time and reduce the amount of time you can wait.
Also, don't overdo it! Just a few drops of white spirit is enough.
Once the size is applied, periodically check its drying condition. To test the tackiness of the size, carefully use the back of your finger with which you
will lightly touch the surface of the object and feel how much 'pull' the size has on the skin (or hairs).
Basically, the longer you can wait, the better the finish - although if it dries completely, you will be back to square one!
Ideally, the size should be at a point around 30 minutes before complete drying.
Okay, the size has just a little tack to it, and you're ready to gild. Load up your 'squirrel tip' from the gilding pad as shown in this guide.
On this particular piece I have opted to use quarter sheets of 23.5 karat loose goldleaf.
Starting in a corner, or appropriate area, lightly place the gold on the tip onto the size. You will want to do this by bringing the tip straight
down onto the surface and then pull the tip straight back up and away. The gold should stick to the size and leave the tip.
Be careful not to let any of the hairs on the gilders tip touch the size and try not to move too fast, as the size will not have enough time to 'grip' the leaf,
so take it slow and steady - especially at first.
If there are recesses on the object you are gilding, try to put the gold into these areas.
However, in most cases, the gold will bridge these areas but will naturally be filled in later when using the skewing mop.
Continue to apply gold to the entire object surface. You should not be too concerned with wasting any of the gold and should allow the pieces of leaf
to overlap sparingly, as it will be easier to skew and fill later. I would say that on decorative areas, you will easily around fifty percent more gold than
the flatter surface areas.
On smaller areas, or where there is a lot of recesses, you can cut the gold into smaller pieces if it is easier. Continue doing this until the entire piece
has been coated with the gold leaf.
Now that the piece is covered in gold (and looking like the picture on the left) it is time to skew it. This involves lightly brushing a squirrel hair gilders
mop over the surface, to remove any excess gold. The generosity of overlapping will really pay off here because this process will also push the
excess flakes into the crevices and hollows of the piece and will fill in any gaps in the work. Do this in a light circular motion. Take care that
the bristles do not come out of the brush and stick to the size. I usually place larger pieces of gold in various areas as added extra filling,
ensuring complete coverage and aiding the process.
At this point you should be finished! If there are any gaps in the piece (perhaps where there is a missed spot of size) you should go over with a
thin artist’s brush and spot gild these areas with the same techniques used. You must always be careful with the gilded surface as the size doesn’t
ever truly dry because it can’t get into contact with the air through the gold, so to some degree it can be scraped off. However, after a few days
it will be quite firm and should be able to be handled carefully.