Gray Tank Heater - above or below?

[rickst29]

When I look at this one, http://www.ebay.com/itm/JR-Products-...2744362http://; or this one, http://www.dyersonline.com/ultraheat...nk-heater.html it seems like a bad idea to stick them on underneath, exposed to road debris.

Has anyone installed something like this, or does everyone else just use RV antifreeze to keep the gray tank from freezing?

[scrubjaysnest]

The only time this has been a concern was with our "other camper". For the short time required, about a week, a drop light was placed under the camper near the holding tanks. Normally I would think just empty the gray water tank would suffice. For some type of permanent installation the heat trace, tape, should be no more subject to road debris then the break wiring.

[rickst29]

I'll be doing it, with a slight variation:

The neighbors might not appreciate a really bright light glowing form underneath my TM at 3 in the morning. And if the wind comes up, a lot of heat from a "trouble light" hung underneath will get blown away from the location it's needed.
So, I'll wrap the bulb in aluminum HVAC tape to prevent any light from coming out (the thick aluminum, not any sort of lesser "duct tape" or flex duct tape"). And, I'll use the same tape on the bottom of the tank, to spread the heat around a large area of the plastic. (THAT tape can be permanent.)
Then, when I arrive in camp, I'll attach my fixture (a 3-WIRE fixture) right against the tank - using the exact same tape.

Thank you!

[Bill]

I've not done this, and I have no plans for cold-weather camping, but how about this? Get a 5-gallon drywall bucket. Put the trouble light in the bottom of the bucket. Put blocks under the bucket to raise the lip loosely against the underside of the gray tank. Make a hot toddy. Enjoy.

A plastic tub might also work, but if the light moves and the bulb touches the plastic, I think it might melt. Drywall buckets are TOUGH.

Bill