I am trying to find out if ther is any way to install some form of heating pan under a tub. Not a jetted tub but a regular non-metal bathtub. Something that heats the basin and keeps it warm. Assuming I find something what would be the best way to insulate it, spray foam, fiberglass? Anyone have any suggestions?
I would have answered sooner, but I was laughing too hard................
Aside from the open-flame suggestion, you may try the electric elements that they make for heating tile floors: http://www.suntouch.com/
You'll have to keep in mind the type of material that is under the tub, as some come with a thick layer of foam that may do nothing in terms of heat transmission.
Go to their site and send them your idea. I'm sure it's doable somehow.
Now about boiling two guys over an open flame............How long until done?