Like Boss Lady, I used double faced foil bubble pac on the hull insides of my engine room. Mine was about 1/4" thick and available at some home centers..used for garage insulation, among other things. But the hull protrusions were so irregular, I first cut sections of 1" closed cell foam insulation (Home Depot, Lowes,etc) which I "glued" to the hull sides with "Great Stuff" (aerosol foam insulation, same sources). I worked around terminal blocks, side hull pipe blocks,etc. Then I glued the foil faced bubble pac to the foam....via "Great Stuff"
Problem: After several years in a salty environment the shiny foil was dulled and had pinholes of corrosion. So I bought some sheets of countertop material (like formica, but different brands available, perhaps 1/32" thick) and fit several pieces over the bubble pac. Easy to wipe down, very durable, not expensive. Only draw back: several seams visible, but I fit them like shingles so any possible liquid intrusion will down not behind the finish. As I leave heat aboard all winter, this made a big difference in engine room temp and I had to remove a section of hot water basrboard radiation as it was too warm relative to the rest of the boat.
