Tortoiseshell Box Conservation Series – A Domed Box With Cracked Shell (Part 2)


Given that the cracked domed lid was essentially two problems, the first being the loss of structural integrity as a result of the fracture, the second being that the two adjacent sectors on either side of the fracture were no longer aligned with each other, I had to approach the problem from two routes to address the two problems.

The first route, and the theme of this post, was to create a means by which the two sectors could be brought into alignment.  To accomplish this required a form that could be used as a caul to force the two misaligned parts into alignment.  There were in turn a number of material techniques to creating the form, including most commonly employing plaster, auto body filler, and silicone putty.  I selected the last one.


Silicone molding rubbers can be used to create the most intricate molds that reflect the character of the surface at a microscopic level.  I didn’t need that, all I needed was a wad of reacted silicone putty that was in the right shape.


So, I made the form by first draping the exact opposite corner of the lid with cling wrap, not worrying too much about getting a smooth fit without folds and creases.  All I wanted was something that could protect the substrate from the silicone, and the putty could assume the general shape of the domed lid.


Using the two-part silicone putty, I kneaded a wad the right size and pressed it against the cling wrap firmly enough so that I could leave it in place with a perfect support form as the result.


I worked.  I trimmed it a bit after it cured, but I was left with a form I could use going forward.


Next time, repairing the crack in the right profile.