Saturday, December 31, 2011

Skills Development: Good as Gold

I have been fortunate this year to be able to take almost a month off from regular scheduled work for skills development. There are things I wanted to brush up on, alternative techniques I wanted to try, and new skills that I wanted to gain.

I've spent time hand cutting dovetails, sprucing up on french polishing, hammer veneering, trying new veneer patching methods, learning lipase enzyme cleaning formulation and application, gained greater insight into the use of ultraviolet lighting for examination, and finally began gaining confidence in gilding.

This month has been really different from the hustle and bustle of working on client projects. It's been nice to regain perspective after this year's busy season by taking a breath and slowing down for a few weeks.

Here is one of my projects from the past month:

Oil/Mordant Gilding

It is not uncommon for a furniture restorer/conservator to encounter a gilded surface on objects entrusted to their care. Not having a certain level of comfort handling these situations can be a great hindrance to a satisfactory and/or comprehensive treatment.

Back in fall time, I spent some time with a friend Colin Barclay, landscape painter. Colin fabricates and gilds his own frames for his paintings. He was gracious enough to give me an introduction to the craft. Building on that experience, I have been reading much since then. It was not until this month that I was able to carve out some time to bring it the bench.

I had a few legs from a discarded sewing table lying around and thought they would make suitable test substrate for the trials. Even though it is not necessary to have gesso underneath oil gilding, I wanted to try both oil and water gilding on the same piece so I decided it would be great practice to gesso the entirety of the leg. The process starts with sizing the surface with rabbit skin glue (9 parts water to 1 part granules). To make the gesso, mix calcium carbonate into the rabbit skin glue mixture until it gets the consistency of heavy cream. The gesso is applied to the sized substrate with carefulness not to obscure the carved/turned details. You will know when to apply the next coat of gesso when the drying surface begins to turn from a grey to white on the high spots. This usually occurs within minutes.

Usually, 3-6 coats of gesso are applied. This will give you enough thickness to sand it down to a smooth surface. When the gesso has dried after 24 hours, you can begin to sand with 220 grit sandpaper until the bumps, pits, and irregularities are mitigated. Following the sanding, a damp cotton cloth is used further smooth out the texture.

Now that you have the smoothed gesso surface, you can seal it with 1# cut shellac. (This is not done with water gilding.) The sealing prevents the oil size/mordant from being soaked into the gesso too much. When the shellac is fully dry (an hour or so), you can apply the oil size. I used Rolco's Quick Size. This is said to be ready to gild in 1-3 hours as opposed to the 12 hour wait time of slow dry size. (Mine was an hour and a quarter.) The size was applied with a 1" squirrel hair brush.

The goal is to make the mordant as smooth and brush stroke-free as possible. Once sized, the piece is set aside in a dust free environment to set up to be ready for gilding.

The mordant is ready when your knuckle lightly touched against the surface is not pulled and when the size makes a squeaking sound when your knuckle is dragged across it.

Gold leaf is thin. Very thin. 1/125,000th of an inch thin. You cannot pick it up with your fingers without talcum power or it will fall apart. For this project, I used Monarch "French Pale" 22kt gold leaf. In order to transfer the leaf from its book onto the object, a tool called a "gilder's tip" is used. A "gilder's tip" is a row of squirrel hair glued between two pieces of cardboard. The squirrel hair is lightly brushed against your skin or hair to pick up oils used to grip the gold leaf. Some people have said that it is static electricity that picks up the leaf, but this is a misunderstanding. When the tip is ready, it is gently placed onto the edge of the leaf and picked up. Don't breathe. Don't make any sudden movements. Don't let any drafts in your studio. The slightest breeze will send your leaf flying into a crumpled mess.

The leaf is gently placed onto the sized surface. When the leaf touches down, it's there to stay so it’s important to make sure to line it up correctly before laying it down. On low spots of carvings or turnings, you can use the skewings (unused fragments) to fill in any holidays that appear.

After all holidays are filled, you can use a stiff bristle brush to lightly knock down any wrinkles on the surface. Finally, soft cotton can be used for a final rub to achieve your sheen.

On this piece, I decided to patinate it to simulate the experience of in-gilding on an antique object. The patination begins with a light solvent wipe to remove gold from high spots. I used VM&P Naphtha for this. The leg was then coated with a pigmented 1# cut shellac followed by pigmented wax applied and left in the recesses. The result was an appropriately worn and patinated gilded surface.

I thoroughly appreciated the experience and have gained considerable confidence with the craft. I look forward to trying out in-gilding using a reversible mordant like Acryloid B-72 Jonathon Thorton discusses in his excellent paper, "The Use of Non-Traditional Gilding Methods and Materials in Conservation" in Gilded Wood: Conservation and History.

Further Reading:

Marx, Ina Brosseau, and Allen Marx. Furniture restoration: step-by-step tips and techniques for professional results. New York: Watson-Guptill Publications, 2007. Print.

Mactaggart, Peter, and Ann Mactaggart. Practical gilding. London: Archetype, 2002. Print.

Rivers, Shayne, and Nick Umney. Conservation of furniture. Oxford, England: Butterworth Heinemann, 2003. Print.

Bigelow, Deborah. Gilded wood: conservation and history. Madison, Conn.: Sound View Press, 1991. Print.

Chambers, Donald L.. How to gold leaf antiques and other art objects;. New York: Crown Publishers, 1973. Print.

Wednesday, December 21, 2011

Thursday, December 15, 2011

Photo Tour: Lie-Nielson Open House!

I had the privilege to attend Lie-Nielson's Winter Open House this past weekend. I had yet to get an opportunity to tour their facilities even though I live only an hour and a half away. I thought I'd seize the moment and swing by. I snapped some photos of my time: I got a tour of the factory (which sold me on their tools, by the way), saw the demonstrators (including Peter Follansbee and Chris Becksvoort), and stopped in the shop where all the tools were on display. It was quite a trip... one that I'd recommend to any hand tool enthusiast.

Wednesday, December 7, 2011

Monday, November 21, 2011

Look Papa, I'm Fissin Furniture!

My son, Eden, said this morning, "Papa, I'm fissin' furniture!" It was amazing.

Saturday, November 12, 2011

The Moment For Which I Await

After development of a condition report and treatment proposal prompting consolidation of coating and/or substrate, vacuuming, and aqueous and petroleum distillate cleaning, there are few treatments that give such instant gratification as the reclaiming of optical saturation through fresh application of a solvent release coating. The glow and gleam of a coating born anew almost smiles back with gratitude. This moment of the treatment is the one for which I await with most anticipation.

Saturday, November 5, 2011

Making Aqueous Shellac

Water-based shellac? You mean you can get shellac, which is soluble in alcohol, to dissolve in water and be used the same way? That’s right.


Before I walk through the process, let me give a quick insight into why this “magic” works: The key here is to understand molecular polarity. It is helpful to think of polarity as a line with one end of the spectrum being polar and the opposite being non-polar. All materials fall somewhere on the line of polarity. For a material to dissolve, it must be introduced to a solvent of the same polarity. Water is very polar and petroleum products are non-polar. Hence, oil and water don’t mix. A solid that is non-polar will dissolve in non-polar solvents, like mineral spirits. A solid that is polar will dissolve in polar solvents, like water.

So, if the shellac resin is soluble in alcohol, how then can we get it to dissolve into water (which is slightly more polar than alcohol)? Answer: Change the ph of the water.

By adding a small amount of Sodium Tetraborate (commercially sold as “Borax”) to the water you cause it’s polarity to shift toward that of alcohol. Get the proportion right, and the shellac begins to dissolve.

This slightly over-simplified explanation is useful enough for our workbench experiment.


A dear friend of mine, Craig Cianciolo, Wood Finishing Specialist at U.S. House of Representatives, shared the recipe he developed from reading Robert D. Mussey and Edward Hicks. He has given me permission to share my experiment here on The Diary.

Aqueous shellac, or Water-borne / water-based Shellac, begins with a list of ingredients and supplies:

A hot plate or stovetop
A small sauce pan
A glass jar (with lid)
Fine Mesh Paint Filter
Distilled Water
Borax 20 Mule Team
Dewaxed Shellac Flakes

The process begins by putting 12 parts (by volume) distilled water into the jar. The jar (with lid on) is placed into the saucepan and water is filled to the water level in the jar. (Make sure you place it onto a dishcloth or such so that the glass isn’t touching the bottom of the pan.)

Heat your 12 parts water up to just below boiling (170-190 degrees or so). Remove the jar from the pan and add 1 part Borax into the water, stirring until fully dissolved.

Once dissolved, the ph of the water has shifted. You can now dissolve your shellac. Take 2 parts dewaxed shellac flakes and pour them a little at a time into the jar, stirring frequently. The shellac, as always, will take a little while to dissolve. It took me a few hours for this to dissolve completely. Coming back over the next few hours to give the jar another stirring definitely helps the process.

When cooled down, and strained through a fine mesh filter, this finish can be applied like solvent shellac. Other than a longer dry time it seems to perform very similarly in all other ways.

I personally found this formula a little light and desired a “heavier cut” of shellac. After experimenting, I reheated the finish in the saucepan, and dissolved 2 additional parts shellac into the solution. It worked like a charm.


My final aqueous shellac recipe, measured by volume:

12 parts distilled water
1 part Borax 12 Mule Team
4 parts dewaxed shellac flakes

So with this recipe you can make your own homemade aqueous shellac. Using it is a bit surreal, I must admit. The harshness of the alcohol smell has been so closely associated with shellac in my mind and the aqueous version just smells kinda… well… fruity. It’s quite pleasant really. I recommend you give it a shot. I think it may be worth your time experimenting.

Further Reading on Solubility:

Chris Stavroudis and Sharon Blank, Solvents & Sensibility, WAAC Newsletter, Volume 11, Number 2, May 1989, pp.2-10

Rivers and Umney, Conservation of Furniture, Butterworth-Heinemann, 2003, pp.515-526