SpudFiles

If you are heating this up to 70-80 degrees then you have nothing to worry about with that pvc tank-holder. As long as you remain 100 or below, you should be fine.

As for insulating this, use one wrap of duct tape around the bottle.

I'd also put a tempy gauge on this thing. Maybe get fancy and hook the heater circuit with a relay connected to a temperature switch. You should make this heater adjustable with a potentiometer too.

w/e this is why i dont use combustion , y dose every one over power things like if pipes r rated for 80psi y shuld u go over that amout ur just putting urself at risk even with combution that is what my dad (mechanical engineer said)

Wow your an idiot read everything before you post. He is just heating his tank so it doesn't take 5minutes to fill his gun he isn't overpressurizing anything.

Sorry if you have already decided on one of these ideas because then I would just be adding this for nothing, but if you somehow modded an electric blanket to run on a battery you could just wrap it around the tank.