I wish that I'd had a fume hood already for much of this project, instead, I've been overhauling one that I rescued from surplus to install in the lab. It came from the Marine Science lab, so is fairly well coated with salt that needed scrubbing off, in addition to removal of the sink. On testing, the fan and lights still worked great, so I onward I go.
Step one was pulling out the sink, cutting a piece of plywood to fit, and glassing the hole flush. I used layers of woven fiberglass and Gougeon Brothers West Systems Marine Epoxy to fill that gap, along with another hole in the right back corner. I sanded the bottom of the hood heavily, and then began painting in the same epoxy, pigmented black, to completely cover the fiberglass bottom. This will create a durable, easy to clean and repair surface for the light acid preparation, resin mixing, and fumed silica work that will take place in the hood. Our welding shop is fabricating a base to support the hood and surround the acid cabinet that will be placed below.
I'll post more pictures when the project is finished and installed.