Question: I recently had some new underwater lights installed on my boat. In the photo you can see the control modules for the lights and the backs of the fixtures, as well as several bus bars the installer put in my boat.
My question is, what is the light brown goop all over the backs of the light fixtures and the bus bars? It looks like a sticky mess, and definitely wasn’t there before the installation. I’m guessing it’s to protect the equipment?
Answer: Yes, from the looks of it, your installer sprayed the bus bars and terminal attachments at the back of your lights with a corrosion-inhibiting spray. He just didn’t do it very neatly.
There are a variety of products out in the marketplace that are effective at hermetically sealing the surfaces they get sprayed on. I use a product called Boeshield T-9 for this purpose. CRC, Mercury Marine, and others also sell corrosion-inhibiting aerosol sprays. I prefer the Boeshield because it dries relatively clear and does not leave a tacky finish once dried.
The Mercury product, by comparison, reminds me of some of the wax coatings that we used to see applied to steel automotive and motorcycle parts to keep them from rusting in storage. It was always a bit tacky and more opaque, and somewhat of a goopy mess to clean off before using the parts.
In your case, the spray job definitely could have been neater. You could use a little acetone on a rag to clean up some of the over-spray, but keep those bus bars and the terminals coated.