The curved foam sandwich anchor lockers in front of my main beam were poorly made. I guess the foam and the outer glass skin weren't attached as well as they ought to have been. Anyway, my moisture meter showed water in there, and after drilling a few test holes, I got wet. So I drilled holes throughout the area that read as damp, 30mm or so apart. I then rinsed the foam by squirting water in turn into the holes, and vaccuuming it back out again. I did this many times!
Eventually, I judged it rinsed enough and let it dry out for several months. Readings with the moisture meter dropped into the green zone. It was time to fill the gaps between the foam and the glass by injecting epoxy.
I've injected epoxy before, and it can be pretty messy. Injecting with a syringe can get the epoxy squirted into quite a large area, but as soon as you take the syringe away it comes out again pretty quick. The easiest part of my problem area was vertical, and some of it even tougher, beyond vertical. I was keen to find a way to plug the holes using something that wouldn't be washed away with epoxy. Masking tape is just washed off by epoxy, and so is gaffer tape. Previously, I've found making a circle of builder's filling mastic round the hole, and then putting tape over it makes a leak-proof seal. But I had a lot of holes, so this method wasn't practical.
One day, I noticed a price tag stuck to a filling knife I was using to work with epoxy. The tag remained well stuck So I bought a roll of 250 price tags. And then cut the roll into three, giving me 750.
I used nearly all of them, but fortunately, I had some assistance. The price tags worked perfectly. They even stuck to the fibreglass that was already wet with epoxy.