More tinkering today. I was looking around for a suitable fuel container and had an old pump garden sprayer. If I let the fuel gravity feed, then it eventually splutters and the burner locks out, but if I pressurise the fuel tank, then it runs really well. I have taken a picture of the burner. It is crude, but it works. It uses about 2 litres an hour (or half a US gallon?). I have also turned the fuel pressure on the delivery pump back down to its original kerosene setting, as it works better this way with the pressurised fuel tank. I still think that once I have preheated the WVO, then I wont need to pressurise the fuel tank, as it will flow much easier,

I have now put a programmable temperature controller on the burner. It is set to fire until it reaches 84C, and then restart when it drops to 75C, so now I don't need to keep an eye on it to make sure it doesn't get too hot.

Just joined altburner yahoo group. Shed loads of information on preheaters, syphon systems etc.

Just catching your first post about gasoline. Never use any gasoline in a furnace/boiler. The vapors are explosive. Heating Oil, Kerosene, Veg Oil, Motor Oil do not have the same problem. They will not easily ignite. They need to be vaporized with just the right air mixture to get them to burn (at room temperatures). Gas/Propane/alcohol all will have vapors that are igniteable with ease.

Carl