Master Bond EP21LV was used in research done at the Fermi National Accelerator Laboratory on the detector for the MiniBooNE (Proposal for the MiniBooNE experiment). Here is a quote from this experiment:

“The detector design requires that the tubes, bases, and cables be immersed in oil for several years without adversely affecting the phototubes or the oil. To accomplish this, the bases and necks of all MiniBooNE PMTs were coated with the two-component epoxy EP21LV from Master Bond, which is impervious to and insoluble in oil.”1

Sources:

1Photomultiplier tubes in the MiniBooNE experiment. Brice, Bugel, Conrad, Fleming, Gladstone, Hawker, Killewald, May, McKenney, Nienaber, Roe, Sandberg, Smith, Wysocki. http://icecube.wisc.edu/~gladstone/papers/article.pdf

Accessed July 2016.