Where There’s Smoke, There’s Yellowed PVOH Gel

Presentation authors: Katheryn Hernandez

Blogpost Summary by Crystal Choi

In the aftermath of the Los Angeles wildfires, several members of the conservation community  have worked (and continue) to respond to fire-damaged artworks. Beyond visible burn damage,  soot, and smoke residues posed serious concerns, particularly since they can contain potentially  toxic heavy metals such as arsenic, lead, mercury, chromium, and cadmium. The contaminants  

can embed themselves into surfaces (i.e., penetrate the skin or remain on the body) and linger  long after a fire, making thorough remediation essential, especially for artworks returning to  homes and living environments. As such, effectively removing soot and residual smoke odor is  an important part of fire remediation. This was the central focus to Katheryn Hernandez’s  presentation, Where There’s Smoke, There’s Yellowed PVOH Gel. 

Hernandez’s presentation discussed the use of PVOH-Borax gel as a cleaning material for  additional remediation of soot and smoke-damaged paintings. Over the past year, The  Conservator’s Easel has treated numerous works affected by the LA wildfires, as well as damage  from an electrical house fire. While traditional dry, aqueous, and solvent-based cleaning methods  remain important first steps, they may not fully remove embedded soot particles. After Head  Conservator Linnaea Saunders attended a workshop on PVOH gel, the studio began testing gel  cleaning to see if it could be a potential solution for further remediation. 

The team found that the best approach for thorough remediation involved an initial vacuuming  and dry cleaning with soot sponges, followed by two passes of the PVOH-Borax gel. Hernandez  showcased case studies during the presentation to demonstrate how effectively the gel lifted soot  from paintings with varying degrees and types of fire damage. 

A key strength they found in using the PVOH-Borax gel is its malleability and clarity. The gel  can be rolled across a surface, introducing minimal moisture while simultaneously capturing  particulate matter. Its cohesive structure reduces residue, making it especially useful on textured  surfaces where aqueous methods can be less effective. Another strength is the gel’s ability to  exhibit a visible color change (from clear to either yellow or black) when it absorbs soot  particles. The presentation provided images of before and after the use of the gels to give further  visual confirmation of this transformation. Repeated applications were also done to reduce  lingering smoke odors. 

Although the gel is effective in its basic form, it can be modified with solvents, surfactants, or  additional gelling agents depending on treatment needs. The gels can leave small pieces of  residue if left out for too long. But any small residues can be quickly lifted using a fresh piece of  gel. 

Overall, Hernandez’s presentation highlighted how adaptable, visually responsive materials like  PVOH-Borax gel can play an important role in fire remediation. In situations where soot carries  both aesthetic and health risks, having a cleaning method that’s controlled, effective, and visually  responsive offers conservators a valuable tool in restoring artworks