I would not mix gasoline and wvo for pushing through a veg oil burner under ANY circumstances. I don’t what you mean when you say „some”, but if the tank has a drain on the bottom, then one suggestion would be to drain it and flush it out with hho. Is that possible?
Even small amounts of gasoline mixed with oil will dramatically increase the risk of explosion in a boiler. I have seen the results of only 1 gallon of gasoline in a 275 gallon tank of fuel oil when there was a delayed ignition in the boiler. Fortunately, no one was hurt but the flying cast iron shrapnel could have killed somebody. How big are the tanks and how much gasoline is in them?
I have a gasoline storage tank on my farm that I wanted to switch to biodiesel. I have been warned that ALL of the gasoline needs to be out of there first because the lean gasoline mix (since biodiesel and WVO have comparatively tiny vapor pressure) creates an equally lean vapor mix in the headspace of the tank, which is an explosion hazard. Apparently this is not a problem when you just have gasoline in there because the vapor saturation is always pretty high. I’m stumped as to how I would get the last dregs out of this buried tank – I sort of gave up after that. If anyone else knows how to “convert” a gasoline tank safely I would love to hear about it.
Gas is lighter than water if you partly fill the tank with water and than drain it from the top down ( yes that means standing there with a hose at the surface unless you can devise a float system but the more from the very surface you get the less will be left after fully drained.
I converted a boat from gasoline to diesel and asked the engine rep about leaving a little gasoline in the tank when I filled with diesel. He told me that anything under ten percent gasoline would cause no trouble for the engine. When using for a furnace, you need to look at how much fuel is dribbled into the firebox when the burner shuts off. Theoretically, there should be none, but even if there was, it would be no more than a couple of drops and if the gasoline is only a minute portion, there probably would not be much danger. Ten percent of a couple of drops might be pushing it, but one or two percent of a couple of drops should not produce an explosive vapor. Regarding tank safety, filling with a less volitile fuel is going to reduce the hazard. You will purge the vapors through the vent as you fill and with each fill the percentage of gasoline will go down till it’s gone.
What happens when you get a delayed start for some reason and the firebox gets filled with gas vapors… boom… I don’t think it would take much gas.. I did this with #2 earlier this year.. accidentally put out the fire and had hho spray on to the red hot fire brick.. instantly filled the firebox with vaporised oil fumes.. I ran for the breaker but was too late.. lucky me, I was right along side the air damper when the thing ignited.. I was instantly turned from nice and clean to dirty sooty black… I was happy it was just oil in there! This is also when I got rid of the flu heat safety switch and hooked up a cad cell flame eye.
I spent most of my afternoon with my uncle who is the town fire chief and when I got home and read this thread I thought of him and laughed, he always says, if sounds dangerous, it probably is… ( : I digress. Here are some very important points to ponder: -there are no waste oil burners UL listed for residential use, NONE. -if a fire occurred due to a “custom” burner setup or waste oil burner, your homeowners insurance would NOT cover you -it is fascinating to delve into all the possibilities of alternate fuels to burn with a Beckett style burner, just please don’t experiment with your home heating system’s burner unless your 200% confident in the safety features you incorporate -agricultural fuels are very safe, and if this can be proven on a large scale, there is hope in a waste/agri oil burner being UL listed for residential use in the near future.
Mixing gasoline and oil in an open cup is not a valid comparison to what could happen in a closed tank or in the combustion chamber of a boiler. It is very hard to predict the actual fuel/air ratio in a boiler of unknown temperature with an unknown amount of unburned mix of gasoline and oil sprayed on to the combustion chamber walls from a faulty start. What I do know is that the boiler exploded when ignition was re-tried and fragments of cast iron imbedded themselves several inches into the concrete walls.