I thought I would chime in on this old thread with my experience in using standard bulbs in my 32v sockets.
I tried about 10 different bulbs with very mixed results however I discovered a very reliable bulb that worked in every 32v fixture on my boat (at least 20). I have not had a single failure in 1.5 years, 70% live aboard. They are also just as bright as the standard 60w incandescent bulbs I replaced. I have also used them in my ER enclosed, sealed fixtures with no heat problems.
They are GE Reveal HD+ bulbs model number LED11DAV3RVL (570 lumens, 10.5W) & LED14DA21RVL (750 Lumens, 14W). They are a bit expensive but can be found on Amazon and Ebay cheaply some times or even on clearance racks. The 750 lumens work excellent but are hard to find and expensive.
I tried many, many different bulbs with less than spectacular results including all other reveal series bulbs and these outshined them all (pun intended).
I actually replaced all 120v and 32v bulbs on the boat and its all been working without a single failure. the bulbs work so well, it is actually not easy to differentiate which ones are on 32v and which ones are on 120v.