Introduction: Waste Oil Furnace for Melting Metal

Picture of Waste Oil Furnace for Melting Metal

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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of The First Melt

It works!


lilviking (author)2017-01-15

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!

AndrewC89 (author)2015-12-24

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?

rjeblogue (author)AndrewC892016-06-07

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.

Jimmy Proton (author)2011-03-09

That wouldn't get hot enough to melt iron.

awest22 (author)Jimmy Proton2016-02-29

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±

spudster (author)2009-02-18

whats an ice maker fitting

sillywilly (author)spudster2015-11-29

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.

rjeblogue (author)spudster2009-02-18

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 .

brown68 (author)2008-05-19

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

Esmagamus (author)brown682008-08-27

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

rjeblogue (author)Esmagamus2008-08-27

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.

rjeblogue (author)rjeblogue2008-08-27

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

Esmagamus (author)rjeblogue2008-08-28

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.

sillywilly (author)Esmagamus2015-11-29

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!

jtobako (author)Esmagamus2009-01-31

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.

rbneville (author)brown682008-08-09

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!

l3lanket (author)lasermaster35312012-10-08

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

Derin (author)rbneville2008-08-17

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!

rjeblogue (author)Derin2008-08-17

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.

Esmagamus (author)rjeblogue2008-08-28

I thought about that problem last night and came up with a idea: cap one end of the brake line, make it stand vertical, heat the line with a propane torch and fill it with solder. Once it's cool, it will be hard to bend the line, but it won't kink and when you're done, you just have to melt the solder again. There's also the ice method, but that's usually used for softer tubing and I'm not sure if ice would be tough enough for this. Maybe a piece of string in the ice core would do the trick.

maybe fill ti with sand. fill it, tap it, fill it some more, until the thing is full and packed well.

you can bend it with a tubing bender. or you can wrap a spring around it and bend it that way. C//////////////////////D it should look like this.(the spring.)

rjeblogue (author)brown682008-05-19

Go to your local auto parts tore and ask for brake line. They will have a display of various pre-cut lengths of steel line that delivers brake fluid to your brake cylinders. It is very in expensive ($3-5 per foot). I also read an article of an oil fired kiln that utilized a water drip line into the oil pool which helps vaporize the oil by causing little explosions in the surface tension of the oil (which is why you don't try to put a grease fire out with water). Good luck-send pics and I'll post them for others to checkout.

sillywilly (author)rjeblogue2009-12-26

Best place to get brake line for a project like this is from a U-pull wrecking yard. Just take a pair of dykes/cutters with you and you will find a endless supply. If you are already buying auto parts, most times they will let you have the line for free! Oh, and don't stick it too far into the burn chamber or it will clog in a hurry from carbonized oil! That thin stainless shot-glass is good for starting waste oil as it gets hot fast but it will burn up pretty quick! Other have used ceramic saucers, cast iron caps, etc. I have even chipped a depression into the top of a firebrick but that was for a larger burn chamber.

overblast (author)sillywilly2011-04-17

Why would I take a pair of dykes with me? They don't even like guys. :<

sillywilly (author)overblast2011-04-17

They do if your not hitting on them!!

lasermaster3531 (author)brown682009-01-30

a steel brake line is a pipe that's made of steel to pipe brake fluid to the brakes on a car. Hence the name.

Esmagamus (author)brown682008-07-15

Well, if you are going to do some glazing, forget it. The residues will probably react with the glaze.

jaqueline xavier (author)2015-10-13

Could you send me information on relations with the area of oil and gas? How can I use this in a job?

jaqueline xavier (author)2015-10-13

Could you send me information on relations with the area of oil and gas? How can I use this in this in a job?

armorer243 (author)2014-12-03

This looks to be a pretty efficient way to burn waste oil. I use a similar setup on my foundry, vaporizing and burning the oil in an external chamber and venting the exhaust and unburned vapor into to furnace to cause a secondary burn. If you are after a clean burn with no smoke and very little odor, this is a good way to go about it.

Another thing this would be good for is as a heater. Just vent the exhaust I to a chamber and blow air around that chamber. Simple, clean, efficient, and safe way to burn waste motor or vegetable oil. Thanks for the write up!

Bverysharp (author)2014-04-12

You can use vegetable oil. It doesn't cause so much creosote and it doesn't have that typically "oily" smell. It also doesn't have additives, and other automobile by-products in it. A really excellent oil burner was designed by Colin Peck in the UK. He routinely melts cast iron. Check out his site:

craftystein (author)2013-01-21

This is really cool and really well done. I think it is interesting to weigh the cost of doing this yourself versus having it done for you. I have included a link to a pricing guide for manufactured oil furnaces as well. Would be interested to hear your feedback and comments on usefulness of potentially building these for different uses, etc.

Cool-fool (author)2012-03-10

I'm thinking about making something like this and have two questions:

1) What is preventing the flame from moving backwards up the fuel line to the reservoir? (Is it because there's no oxygen in the fuel line? Is there anything one could do to make this safer?)

2) Is there any advantage to this shot-glass "carburetor" method over the Brute's pseudo-fuel-injection method? I would think that the method you're using here wastes a lot of heat through the carburetor chamber itself, because the flame must move through the carburetor.

P.S. "The Brute" burner that I'm talking about is here:

Thanks for your advice!

Nagarok (author)Cool-fool2012-03-17

For the first question
I'm pretty sure it is that
also the fact that for oil/petrol to burn, it must be a vapor already would have a big effect here. adding it straight into a fire this doesn't mean much, because the oil vaporizes from the heat of the fire, then burns. But in the pipe, the liquid oil would be moving fast enough to push the vapor out the end of the pipe before it has a chance to heat the rest up to vapor.

If you wanted to, you could add a one-way valve somewhere in that so that the oil can go into the chamber, but not flow back up. Or another design feature is to create a "Pop" valve in the oil reservoir. Basically means cutting a small square out of the top, then taping a single layer of cling wrap, or thin tape over the top. So it's still air tight, but if any force builds up in the chamber i.e. explosion, it will go through that hole, instead of actually going boom.

germeten (author)Nagarok2013-01-11

Actually oil is pretty hard to ignite, and in an enclosed area in an absence of air (like the oil line), even more so. Gravity keeps the oil flowing down-hill, there's no pressure to speak of to push it back up. No amount of heat at the far end of the line is going to explode your reservoir, (oil is not an explosive) but does burn well once lit. An oil fire outside your foundry is something you want to take safety steps to prevent. Great idea, man.

rudolphdiesel (author)2012-08-24

"who knows when" self destruct device.

etopsirhc (author)2011-07-07

watch out when it self destructs , u dont want to be around when a molten metal bomb explodes XD

Esmagamus (author)2008-09-01

It would be if it were a babington burner. A great design, by the way. It's capable of handling lots of grime and metal shavings, but it's not very compact for most home uses.

sillywilly (author)Esmagamus2011-04-17

You can build Babington burners big or small! Go look at examples at the Yahoo group "altfuelbabington" You may have to join to look at all the pics but it's an easy join! User "mitchrx7" has a really neat automated one, probably the classiest one on there!

Esmagamus (author)2008-07-15

Nice! Some more ideas for my future oil heater! I don't feel like feeding it with wood all the time.

sillywilly (author)Esmagamus2009-12-26

Just add a tee to the oil line (with additional shutoff) to feed waste paint thinner or perhaps kerosene to warm up the chamber. I have read where this works quite well and usually only takes a few minutes.

Robotics_Geek (author)sillywilly2011-01-20

In mine I just squirt a bulb (an ounce?) of kerosene into the chamber and barely crack the fuel and light. When the waste oil mixes with the kerosene it will burn longer once it's warm enough I open the fuel more. I added copper nails and other copper screws etc. to act as wicks to the bottom of my furnace. It helps dissipate the fuel better and helps it light easier.

mazeka.14 (author)2009-08-29

how hot does it get?

raceryz350 (author)mazeka.142010-05-31

thats what she said

0087adam (author)raceryz3502010-08-02


ticoun (author)2010-05-21

never use homemade refractory with a waste oil burner, because it will melt down pretty fast and turn into glass. if you plan to make a waste oil burner, you must make your furnace with a commercial refractory hotface that's rated for at least iron melting temperatures.

eckopariah (author)2010-02-11

Looks very similar to my aluminum melts with charcoal as a fuel. The metal isn't getting hot enough to melt completely, and you're left with some unmelted metal/slag/dross on the bottom of the crucible. I must say, your burner design looks somewhat inefficient, however VERY creative. I might recommend eliminating the mixing/preheating chamber, and just have the fuel drip right into the airstream, similar to L. Oliver's "Brute" furnace. much simpler design, and he can melt iron with it. That will save you fuel and increase temperatures in a shorter time, because you're not preheating a chamber before the main furnace.

briackman (author)2009-07-05

ey, can you make one with vegetable oil, probably not but i'm just wondering

About This Instructable




Bio: 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 ... More »
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