The restoration of paintings is generally a serious business,
more paintings get ruined by enthusiastic, careless restoration, than by fire.
We like to warn the reader that the restoration and/or cleaning of valuable oilpaintings should be left to a reputable professional expert.
One can become an expert, by years of practice, using the techniques described below, as it takes the practice of cleaning many paintings and a sharp eye as well as insight into what is happening to become an expert.
Depending on what you are restoring there could be some tax advantage on the item because of the value of what you are restoring. If it is for an old valuable painting that is a business there would be tax deductions for the supplies to restore the building. Use the income tax calculator and in contact with your local tax preparation site or place.
If one, however likes the idea of cleaning ones own paintings then, it might be advisable to buy some cheap paintings and restore those, to gain some first hand experience.
This subjects handles;
The Cleaning of Paintings
Cleaning the Painting
Old pictures get often very dull and muted by dirt, smoke, clouded varnish etc. etc. sometimes to the extent that the picture is hardly visible any more.
The painting can then be cleaned.
Deframing the Painting
Once one has decided that the time has come to clean an oil painting it is best to remove it from the frame.
Lay the painting, with the back up, upon a flat stable surface, such as a workbench or table, which is covered with a soft cushioning material, such as a doubled blanked or polyurethane foam, to avoid damaging the frame.
Carefully vacuum most of the dust of the back of the painting and frame.
Hand cut or wrought iron nails should be removed with care, using pliers and a flat piece of metal, such as an old ruler, for the pliers to lever against, thus avoiding damage to the frame.
Remember to always seek medical advice, should you slip and hurt yourself while removing the nails,
On a piece of timber or board, previously marked in sections "Left", "Top", "Right", "Bottom", and those each, marked respectively, top-bottom, left-right, top-bottom, and left-right, then the nails can be stuck, using masking tape, so that they each can be re-used in the same position as it was removed.
Most often it is not necessary to remove the nails from the bottom as the painting is easily removed from the frame by just removing the other three rows.
Wire nails can often just be bend and bend back when the picture is replaced.
Using the crevice tool on the vacuum cleaner suck the dust carefully from between the canvas and the stretcher (the wooden frame upon which the canvas is stretched).
Great care is needed during the vacuuming to avoid the flaking or cracking of the paint, thereto ones often deploys a small blunt hooked knife to loosen the dust carefully between the canvas and stretcher during the vacuuming.
Also note if all the corner wedges are there as replacement wedges can be ordered while cleaning the painting.
Removing the Foxing
Foxing is a form of mildew and is most easily removed with and anti-mildew agent, containing Sodium Hypochloride, such as the commercial "Mould Rit", "Exit Mould" or such available at the supermarket.
A clean Cotton wool ball is sprayed with or dipped in this solution.
The affected area is then lightly rubbed with the anti-mildew agent and then wipe with clean water on a sponge until all traces of the anti-mildew agent are removed.
Do not leave the anti-mildew agent on the painting for a prolonged time.
Check the Cotton wool ball for color so that no paint is removed.
Very light cleaning can be done by cutting a onion in two and rubbing the painting with the half onion the combination of the chemical and mechanical have a good cleaning effect which is intensified by the addition of some lemon juice drops.
While working cut, from time to time a thin slice of the onion to refresh and clean it.
Wipe with a wet sponge to clean the painting before allowing it to dry.
Medium light cleaning is done using hand warm water and lemon detergent with a soft sponge.
The sponge should not be more wet than necessary to avoid soaking the canvas.
This method is often very effective and removes much of the grime and smoke accumulated on the painting.
Rinse the sponge often give the detergent time to work on the grime.
Make sure to wipe the whole painting repeatedly with a clean sponge to remove all traces of the detergent.
Medium cleaning is done using Washing Soda or Lectric Soda (Sodium Carbonate) depending upon which term is used in your locale.
Great care should be taken during the application as well as for determine its strength.
A pinch of soda crystals is dissolved in a cup or saucer with hand warm water, stirring until all crystals are dissolved.
Using a ball of cottonwool dipped in the solution, a corner of the painting is wetted for trial.
Rubbing the area with the cottonwool in circular motion the effect is noted.
If there is little or no effect, another pinch is added to the solution as before and another trial is made.
Rinse the painting thoroughly, using a soft sponge, to remove all traces of the soda, as it will leave white marks on the painting.
You'll be pleasantly surprised by the regained color depth of the painting.
Removing the Varnish
In Depth cleaning is done by removing the varnish.
Oil paintings are normally coated with a layer of varnish.
This layer is applied for the protection of the painting, so that dirt and grime don't directly attach to and enter into the paint.
When this layer becomes to dirty for light cleaning then this layer of varnish is removed, the painting cleaned and a new layer of varnish is applied, making the painting ready for display again.
This varnish layer is removed, with a pad of cotton wool dipped in methylated spirits, to prevent the methylated spirits from working to deep into the paint, a second pad of cottonwool, this one dipped in turpentine is at the ready to arrest the workings of the methylated spirits.
As this cleaning has a dessicating action upon the paint, most restorers dilute some linseed oil into the turpentine to alleviate this problem.
Before starting this in depth cleaning one should take the time to fix the values of the painting if not photographically than certainly in ones mind.
This way the balance of the painting can be maintained.
Lighter colors always clean well but one should be aware that the darker colors dissolve quicker and should therefore be handled with great care.
Sometimes a painting has been "adjusted" at a later stage either to "improve" the picture, to suit a fashion (making it more sellable ), or to hide a bad repair.
This "adjusting" is most times done by coloring the varnish so giving the picture a mood or attempting to make it look older than it is.
When one cleans the picture those "adjustments" are removed giving you a clear look at the real picture.
Adjustments made to hide a tear or hole often includes the addition of a figure, such as a cow or tree or the extention of a building.
The paint used for those "improvements" invariably dissolve easier then the surrounding paint, when cleaning the picture and one should be continuously aware of this possibility.
Therefor it is necessary to check ones cotton wool pad each time it leaves the picture to ensure that no paint is removed from the picture.
If this however is happening then arrest the dissolving action of the methylated spirits instantly, by applying turpentine to this area and after examination let the picture dry for an extended period.
After which one can continue with further cleaning where necessary.
Flaking and Blistering
When the paint is flaking, blistering or scaling, a condition in which the paint and ground lifts from the canvas, due to the deterioration of the ground (then material used to smooth the canvas before the painting was applied).
The paint then is re-adhered to the painting by strengthening this ground.
This is usually done by impregnating the area with a mixture of Beeswax and Damar resin, known as the Dutch Method.
We recommend the impregnate most canvasses with this mixture as it prevents deterioration of the canvas and the ground, as well as the overall conservation/ preservation of the whole painting.
Beeswax and Damar are molten and mixed together by heating firstly the Damar until dissolved and then slowly adding the Beeswax.
This mixture is applied warm ( 70° -80°C or 160°-175° F).
A mixture such as above doesn't shrink upon solidifying.
Epoxy is sometimes used in those sort of repairs, as it also is non-shrinking due to the lack of an evaporative vehicle, it (epoxy) solidifies by chemical reaction, however great care should be taken with the use of such materials, as those restorations are non-reversible, and no long term experience is available, while contrary to claims, epoxies do deteriorate.
I personally like to dissolve some of this Beeswax and Damar mixture with some pure turpentine and then flood the flaking area with a brush very carefully so as not to disturb the loose pieces but still let the mixture impregnate the area behind and around the flakes and blisters.
Those flakes can then be re-adhered and flattened with a heated palette knife.
After thorough drying I paste some paper over this section, for protection, then after drying I apply paper over the whole painting, this protects the texture of the painting during the ironing process.
Then after drying I turn the picture over and apply the mixture of Beeswax and Damar warm ( 70° -80°C or 160°-175° F ) on the back, then with an Electric Iron, I iron the area down so as to impregnate the whole picture with this preservative mixture, this flattens and re-adheres the blisters and flakes back against the now impregnated and strengthened ground.
Those with flat heated platen can of course do this by vacuum pressing the painting against those platen, this also allows the painting to maintain its texture.
After cooling I then carefully wash the paper away, the examine the result to determine the further processes needed to complete the restoration.
The reason I prefer this, Dutch Method, is that it is reversible, one can always reheat an area and relocate any pieces of flakes, which are not where one wanted them, something which is impossible if epoxy is used.
Repairing Tears and Holes
Tears or holes in the canvas can be repaired by flatten the existing canvas, applying a new piece of canvas to the back and touching up the paint.
This canvas can be applied over, just the torn area, or hole, or in case of badly deteriorated canvas, over the whole back, which then is often called re-canvassing, but more generally known as re-lining.
One first flattens the edges of the tear or hole by applying a piece of canvas to the back with a Beeswax and Damar mixture.
Tears can be tightened by waxing narrow longish strips across the tear, first on one side, and after cooling on the other side while pulling the tear close by the end of the strip.
If one uses strips of say, 1cm or 3/8" wide, then apply the first one across the center of the tear and then one on either side of this center strip, leaving a gap the width of a strip for later insertion of a strip, and, pulling alternatively from the opposite directions, ensuring an even pull across the tear.
After those are done, insert strips in the gaps so that the whole area is covered.
As each section is done check that the fibers of the canvas lay in a natural position and are not doubled and stuck underneath causing unsightly bumps.
Crooked fibers can be straightened using an old heated dentist tool (metal hook).
Check from the front when the whole area is covered that it appears "natural" e. i. so that is doesn't pull or have wrinkles.
Remove any excess wax from the front, using turpentine and let the picture "rest" for a while.
If the picture needs complete re-lining the apply paper as in
"Re-Canvassing or Re-Lining"
Then after the paper is dry and properly adhered across the tear or hole, remove the strips before the re-lining, by slightly warming the canvas strips, so that there is no doubling up of new canvas.
Which after a while would be showing from the front of the picture.
Once the hole or tear is repaired with canvas the painting can be restored at the front.
Fill the hole or tear with ground which can be made by, dissolving some fish glue or gelatin in warm water and then adding chalk to thicken the ground to a putty like substance.
This may then be applied with a spatula and left to dry, remove any obvious excess before drying and remove excess on the painting with warm water directly upon drying.
The coloring may now proceed, most restorers prefer to use just pigment and egg yolk for the coloring.
This not only dries much faster then oil paint but is also easier removable if the restoration is deemed, non-sympathetic, upon examination of the whole.
Once one is satisfied with the repair, one can finish the restoration by
revarnishing the painting.
Re-Lining or Transferring the Painting
Transferral of the painting to a new base is mainly done with paintings on wood panels, which are deteriorated to a level where the need to put the painting on another more stable panel cannot be avoided.
Canvas backed painting are generally just re-lined, which is the placement of a new canvas over the old one, although the old canvas is often thinned by sanding some of the old canvas away.
Both processes start by the application of paper onto the paint, thus providing a stable environment for the paint during those processes.
One starts by applying first a layer of soft paper, like tissue paper with paste.
After the first layer is successfully adhered to the paint it is strengthened by applying a layer of gauze, then one applies a layer of supple stronger paper, followed by layers of heavier papers.
Make sure that the surface of the paper becomes flat so that if one lays the painting down it doesn't bend, for extra strength one can finish of with a layer of canvas.
Let the paper layers dry thoroughly, and if the painting is on canvas remove carefully from the stretchers.
The timber can now be removed from the paint either carefully with a router making first grooves across the panel after which the timber in between is removed leaving enough timber so as not to damage the paint.
Or by sawing kerfs across the painting and removing the timber in between by careful splitting, leaving enough timber so as not to damage the paint.
The rest of the timber is best removed with a sharp slightly rounded gouge, sharpened so that the outsides cut the timber before the center, this way one can cut across the timber while cutting still along the grain, thus avoiding breakout.
Once all the timber is removed one can carefully remove the ground if necessary and have then the unique opportunity to view the picture from the obverse site.
The painting may now be cemented to an inert board or Treated Balsawood Panel for support.
After cooling the pasted paper and canvas can be removed with water by carefully dampening and removing bit by bit.
Revarnishing the Painting
All paintings should be varnished it is not only essential for preservation but also improves the appearance of the painting.
The Revarnishing of the painting is a simple procedure make sure you're in a dry environment at room temperature.
You may chose a matt or gloss varnish depending upon your preference and the subject and period of the painting.
Using a flat varnishing brush.
Start at the top and work your way down using crisscross movements.
Make sure you can have striking light on the picture so you can see the bare or thin patches as well as avoiding any runners.
Let dry in a warm dust free room.
Conservators and Restorers of Paintings
If you have experience in improved methods then please let us know by