Three to four weeks ago, I decided to dry strip a mirror I'd purchased, not just to save money, but because gilders have to charge the same amount for their time whether doing sophisticated clay color applications and gilding or for dry stripping subsequent layers off of original gilding, a job that can best be described as grunt work that requires savvy. And if you are remotely obsessive compulsive, which I can be from time to time, it is a satisfying pastime. Not that I would want to be chained to a bench for eight hours a day dry stripping, but the infrequent chipping away at stuff that just pops off when you apply the right kind of pressure is a little like pulling a scab off at the right time--very satisfying. In addition, you have the opportunity to reveal the intent of both the carver and gilder in removing the subsequent layers of gilding that were applied by restorers who never seemed to care about using the original colors of either clay or gold. In addition, the stuff your are stripping obscures the finer points of carving. It is a job that takes time and care as you don't want to damage the original layer nor do you want to enhance it. As sensitive as it can be, it isn't exactly rocket science.
It helps to have a number of different tools. Dentists from the past have given me a bunch of scrapers that are very handy. The problem is that you can't get much leverage on them--cleaning teeth doesn't require too much pressure, but getting old gesso off does and the thin metal handles of dental tools aren't always the right tool. Hence, a set of carving chisels are also useful. Sometimes it can help to spray a little water on the surface half an hour in advance to loosen things up just a bit, but you need to be careful as you don't want to soak the piece. A number of things will start to come clear as you start to chip away as, for example, some previous gilders may have taken removable parts off (a cartouche or a rosette, perhaps) to completely strip them to the wood and then re-gild from scratch--this is a little aggravating because, as noted above, they seldom use the right clay color when re-gilding, but it is what it is and you just have to accept it. And even more interesting fact is that you can tell whether the carver was left or right handed. As much as a carver wants symmetry, at least in either baroque or neoclassical mirrors, his or her dominant hand reveals itself.
Gilded mirrors served an important function in the lighting of a room, something I have talked about at length. I've also mentioned that a brightly gilded mirror was preferable, whether water or oil gilded. Today, re-gilders do not want brightness as it can appear garish so they do what is known as toning, done with colored dusts and rubbing gold off artistically. When you dry strip, particularly if you don't use water, there is little to no toning to be done. Patching bare spots is inevitable as there are areas which for some reason or other have lost their gesso--dampness is usually the culprit, but bad handling is another. The patching may need to be done onto raw wood, it may require some color to overly large white patches of gesso and in some cases a little gold. A great gilder can handle all of these instances as that is their metier--it is not something that your local frame shop can do unless they have access to a gilder who understands the history of gilding. The mirror that I just worked on will be on my stand at the Winter Show (tickets for those of you that want them) where I will be able to point out the left and right hand differences and show you the difference in tone between fully regilded mirrors versus mirrors where the gilding has been saved. For me, dry stripping enhances the value of an object as long as the patching process is kept to a minimum because once you start to patch everything, you will lose the aesthetic of the dry strip--at that point, you might just as well have dipped, stripped and re-gilded.