Waste Oil Furnace for Melting Metal





Introduction: Waste Oil Furnace for Melting Metal

About: I like to learn new things.CNC, foundry, Screenprinting, anything electronics related. I like to tear things apart to see how they tick. Unless I can't resist the challenge-rarely do I ever put back together...

Four things inspired me to try an oil fired foundry.Detailed instructions on the net,gallons of oil in my garage from changing my own oil, hassles and cost of constantly filling my propane tank and my recent discovery of an endless source of free oil/gas mix removed from vehicles that are being crushed.

Step 1: The Parts Needed

I found This cast iron pipe fitting at the salvage yard. The blower was also salvaged and the intake and exhaust nipples are pipe nipples I had to buy. I drip the oil down from the top center and have the fan on bottom with the hot flame coming out the top. I preheat the double ended stainless steel cone shaped jigger with my torch for two minutes through the removeable-blower hole until it is glowing red hot ,start the oil dripping and quickly remove the torch and add the blower. A permanent built in Torch head for pre-heat might work better. The blower is controlled with a house lamp dimmer for varying degrees of hi-lo (not recommended for inductance motors). After I was sure the contraption would work I encased it in a can rammed full of refractory

Step 2: It Works

The heat is intense! It's good to do a dry run to see what works best before you permanently bury it in concrete-like refractory.

Step 3: The Reservoir

The fuel storage tank was an empty freon tank recovered from the junk yard. I welded on some removeable legs to elevate it and found fittings to adapt the tank to a ice maker needle valve. The valve has a compression fitting on one end to attach the 1/4 o.d. poly tubing. The valve plugged on the first use so I had to dissasemble and add a 3" long 1/4" o.d. copper tubing standpipe to the nipple that threads through the tank. This keeps the furnace from feeding off the bottom of the tank. Much easier than filtering. This will require a dipstick to calculate the useable fuel level as there will always be some unuseable fuel now

Step 4: The Outer Shell

The inner combustion chamber is shown encased. Christmas Popcorn Tins work good for the outer shell. The refractory material is rammed all around the chamber to insulate on all sides. The blower is removeable for pre-heatingt with the Propane torch.

Step 5: The Burner in Action

Here it is in action. It is blowing the heat into my Furnace melting the metal inside. The metal is usually in a crucible of sorts.

Step 6: Too Hot

It is pictured idling here with a small but sustainable flame. I had to turn it down because within 15 minutes the threaded brass plug and the exhaust nipple began to glow red hot on full throttle. This leads me to believe the entire contraption is bound to self destruct as it reaches the melting point of both brass and cast iron. For this reason my next combustion chamber will be all refractory material incorporating the same pre-heated stainless steel shot glass to vaporize the oil. For now I will use this contraption until my self-destruction prediction comes true.

Step 7: The First Melt

It works!



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    I've built David J. Gingery's gas fired crucible furnace w/3100°refractory and have some of his other books on mouldmaking and "Green" sandcasting. I never thought to try a waste oil burner instead of propane but the cost savings is immediately apparent! Thanks for having me along, I love to learn pratical skills!

    I have a problem keeping the one I made, fired up it will go then Peter out. IDK. Mine is pretty rustic. Crap I acquired and macgyvered into a blast furnace. The concept is there but it doesn't keep going. I'm drip feeding the oil, using a gas leaf blower ďnit at full throttle) but it keeps dying out. Help?

    1 reply

    I think the key is to have the oil come in contact with a red-hot metal to reach its flash point. Kind of like a Coleman lantern. The mantle is red hot carbon and keeps the propane lit. A piece of stainless steel screen would work good. The volume and pressure of air is critical too. Too much and you'll extinguish your flame.

    they do bro. mine is still in the works, but I've melted copper in a cast iron pot. with virtually no refractory material around it. just a few cinder blocks. and copper melts at 1900±

    sorry it took so looooong for someone to answer your question. I think he is referring to a compression union for 1/4" line. It is used often when connecting metal tubing to plastic tubing (or metal-to-metal) for setting up a small water supply to an ice maker in some fancy refrigerators.

    It is a small brass ball valve with 1/4 o.d. compression fittings used for shutting off or turning on the 1/4" plastic water line to the back of a refridgerator for the ice maker water supply line, or sometimes used in the shutoff tot he water suply in an evaporative cooler (swamp cooler). Available in most hardware stores in the US or maybe even on Ebay for under $5 .

    great job, but can you explain to me what is a steel brake line?. I'm interested in building a kiln for firing pottery using waste oil burners

    11 replies

    You should expect to have some problems with glazes if your burners produce any kind of solid contaminants, or even some chemical ones.

    The article I read about using waste oil to heat a pottery kiln was in a third world country where the convenience of clean electricity is not an option. I am guessing it was to fire clay vessels for carrying water. I agree, they may not be glazed vessels of beauty but I'd bet they would hold water.

    (The kiln was in the 3rd world country, not the article) LOL

    So that changes everything. Electrical kilns aren't very common because using gas is a lot cheaper than electricity. Pottery that is not too porous can probably be waterproofed with grease, but that can cause sanitary problems that would be avoidable with glazing, provided it would be food safe glaze, with no lead or other heavy metals (you'd be amazed with the kind of undeclared dangerous chemicals that come in those bags of glazing powder, and the reason why there are almost no available MSDS on glazes is keeping formulas away from other companies). Probably metal cans are a better sanitary choice than unglazed pottery. Still, there's research to be done.

    I know it's been 7 years since you made this comment on glazing for pottery but I post this mostly for the benefit of other readers.Pure wood ash has been used as a glaze for hundreds of years! Some wood sources work better than others but that is a simple solution to the worries about the presence of heavy metals or other chemicals in commercial glazes. Google it!

    Porous pottery has advantages over sealed ones-like the self-cooling by evaporation and the ability of low-fired cookware to be set on a fire without the heat-shock shattering it. Any problems with waste oil contamination could be solved by using a muffle-an inner liner between the flame and the wares. This could be part of the kiln or smaller containers (with lids) make of higher firing clays.

    a steel break line is the line that goes to the brakes on a bike

    bikes don'thave metal brake lines. even high-end bikes that use fluid have nylon(or Kevlar or steel)-reinforced plastic lines. most bikes don't even have brake fluid!

    Wouldn't you consider steel to be a type of metal?

    NO NO NO NO NOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!You got confused,dude.The steel brake line he was talking is used to carry brake oil in a car!

    Derinsleep has got it. It is the hollow steel tubing found on automobile brakes. It typically carries brake fluid from the reservoir to the slave cylinder and master cylinder. It is hard to bend without kinking but is needed to withstand the heat created in this furnace.