kayaker

alternatively I may have a stainless steel 35mm roll film developer canister and some thermal rubber insulation that could wirk for free! I also have an old Digital indoor/outdoor thermometer I could use to monitor the Temp with. The old Hot tub heating aparatice may be too large for my purposes, It used to runn off of 220V AC, I wonder what 12VDC would do with about 30oz of water!?!? Thanks for all the ideas

...Actually the "HotShot" fluid heater heats up to 150 deg F so I guess the 115 deg will work just fine. I would still try to create a separate smaller resivour so that heating and battery use is minimal. A temperature sensor and on/off switch would also be usefull. Maybe using a stainless steel thermose would do! Do you think the pump pressure will be the same??

tnk2k, Your idea sounds good. However, the 115 deg F thermostat sounds too hot considering it will hit a window that is 32 deg F. I might worry about cracking!

I live in the North East and I have recently heard about cars being made with heaters built in for heating the washer fluid.