Background: we had an old painting my wife's aunt had done many years ago. Somehow in its travels it managed to acquire an inch long tear, no doubt from something poking it. The painting wasn't valuable in a monetary sense, but it had sentimental value. I said I'd repair it.
Before going much further I consulted the source of all wisdom, my ancient copy of Ralph Mayer's Artist's Handbook of Materials and Techniques. Among the chapters is one on conservation, which includes a section on repairs. It became my road map for this project.
Mayer described the technique, which involved sticking a primed canvas patch on the back of the tear using a heated beeswax/resin mixture, with a little Venice turpentine thrown in for good measure. You coat the hot wax mix on the primed side of the patch, stick it down, then press with a warm iron.
After cutting away the brown craft paper dust barrier from the back, I found getting getting the brads holding the stretcher in the frame out to be more of a challenge than I was willing to undertake. I decided to do the repairs without removing the stretcher from the frame.
The canvas was medium weight linen (linen? nice!) which had developed some slack as well as moderate deterioration. Something I'd learned from my IT career: avoid scope creep. Since I couldn't get the painting out of the frame, I was going to have to live with the slack and restrict this project to fixing the tear. I used a nail clipper to trim back some loose threads from the tear.
Next I rounded up the ingredients for the wax adhesive: unbleached beeswax, rosin, Venice turpentine. Best advice: mail order these; you will likely not find all of them at your local art supply store. The beeswax I found in batik dyeing supplies -- a one pound brick of it. Needless to say, I have a lot left over. Venice turpentine was a little harder. Toughest was the resin (an alternate is damar varnish -- crystals, not the liquid). I eventually got a piece of violin bow rosin (rosin = resin) which, in a leap of faith, I decided would do just fine.
Once I gathered my ingredients and courage, I measured the resin and wax into a small flat can (a tuna can would be perfect after washing): 5 part wax to 3 parts resin. My mixture was a little wax heavy because I didn't have a lot of resin. I put about an inch of water in a sauce pan, floated the tuna can in it and turned on the heat.
Previously, I'd cut a 5 inch diameter patch out of an unused primed stretched canvas damaged in shipping. Scrap pre-primed canvas would have worked as well.. Word of advice: don't put the water on to boil and leave it unattended to cut your patch.
The water started boiling and the wax, then the resin slowly melted. I gently stirred it with a brush handle to get the two components to mix. The few impurities from the resin I fished out with the brush handle. Once it was thoroughly liquid, I raced outside with the saucepan to my workspace and stirred in the 1 part of Venice turpentine.
Find a brush you can afford to sacrifice if possible; cleaning the mixture out is not a guaranteed thing. I found an old brush and painted the mix onto the primed side of the patch. Once out of the hot water bath it became solid pretty quickly.
I stuck the patch down on the raw backside of the canvas. To aid in placement, I'd previously sketched a circle around the tear. Once in place, I used a clear roller to press it in place, with a piece of card-stock between the patch and the roller. Mayer recommends using a warm, not hot, iron, but I was a little leery of one more thing to coordinate with all this hot wax business. The roller seemed to work adequately. If it hadn't, the iron was plan "B." You want to make sure you have a solid surface to press against to avoid cracking the paint on the canvas.
Just to be on the safe side, I gave the patch a couple of hours to set. The tear, while definitely visible, was now structurally stable and well-adhered to the piece I'd cut to back it.
Fortunately the damaged area was background and not a focal point. I mixed a little oil paint, thinning it with turpentine and in-painted the tear. My goal was not so much to make the repaired place invisible as to simply make it less noticable upon casual examination. When in doubt, make the in-painting less saturated and less detailed. My only regret is that I failed to take process photos documenting the steps I took.
The finished result, while not perfect, was good enough to impress my best beloved.
Just to be on the safe side, I gave the patch a couple of hours to set. The tear, while definitely visible, was now structurally stable and well-adhered to the piece I'd cut to back it.
Fortunately the damaged area was background and not a focal point. I mixed a little oil paint, thinning it with turpentine and in-painted the tear. My goal was not so much to make the repaired place invisible as to simply make it less noticable upon casual examination. When in doubt, make the in-painting less saturated and less detailed. My only regret is that I failed to take process photos documenting the steps I took.
The finished result, while not perfect, was good enough to impress my best beloved.
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