Hi folks! I've been away for a little while, but I found something I thought you'd be interested in and just had to tell you.
I remember reading a post in either this topic or a similar one, in which the writer expressed concern that the heat from the heater cable would cause the water to evaporate before it could be measured in the rain gauge. Different ideas were presented of various treatments one could apply to the collection cone to help the water run through quicker. I think I've found the perfect thing for this.
Rust-Oleum NeverWet Multi-Purpose Spray
http://www.homedepot.com/p/t/204216476It's pretty cheap, and the demo video on the product page looks promising. I got some of this to treat my work boots and gloves, but then I had the idea to apply it to my rain gauge collection funnel as well. I'm currently half-way through the treatment process. There are two spray cans in the kit. You apply a few coats of one, let it dry for about 30 minutes, then apply a few coats of the other. After another 30 minutes of dry time, it's ready to get wet.
Oh, and I'm not just treating the collection funnel, but the seesaw as well. When I opened my rain gauge, the seesaw was pretty dirty from dried dust collected by the rain. I figure if the water runs out of the seesaw better, it may not get as dirty.
With this added, perhaps the title of this thread should be $50 Rain Collector Heater.
I hope this helps someone.