Metal Casting Zone

I am in to making this furnace with as much scrounged material that I can get. If I can make it for free totally, that would be a feat.

I am starting with this drum. The drum I got from a volkswagon dealership. They get their brake fluid in it. It also makes a bang up gas tank or storage tank for waste oil. They hold about 10 gallons.


the drum is 21 inches tall and 11 inches across


I scrounged this piece of HVAC pipe that underground ventilation is piped through. The sides are very smooth. I figure that I'll be able to slide it out of the drum after ramming in the refractory.


I am using 2 parts of #30 sandblasting sand and 1 part fire clay to make the furnace lining. I debated using vermiculite to aid in the insulation. I decided that if it was a problem getting it hot enough then Ill have to bash out the lining and redo it with the vermiculite added or go all the way to a commercially made refractory. As it is I am scrounging and the only thing that I had to buy so far was the fire clay. The sand I had bought to line the bottom of my fish tank but never got to it.
"Hey honey I found a use for that sand that had been kicking around the garage for a year!"


This is what it looks like after it is mixed and wetted down. By the way the fire clay is really hard on the lungs. I bought a resperator just for the job. I came out looking like I had been in a sand storm except where the resperator was.
Ok the resperator wasn't scrounged but Ill probably use it when I am weedeating to keep the grass guts out of my nose and mouth.


next... on to making the tuere pipe and waste oil burner.

Wrap the liner pipe with 3 to 5 layers of wax paper to help it slide out. That's a nice size can. Are you going to cut a section off the top for a lid? Make sure you anchor it good, so the refractory doesn't fall out when you get it up to heat, like mine did.

Ooohh thats a good tip!
I had planned on sectioning a one foot slab off the top to include the handles so that I could remove the lid easier when it is hot. I did have plans to spider web the inside of the lid with fencing wire. (about 10 guage) I found a roll of in the middle of a field. Should I make one layer on top of the other, with a 4 inch space between top and bottom layer?
I looked through the net at everyones different ideas for a oil burner. I think that the injuection style is going to work the best. I was trying to come up with a way that I could plug in something that would preheat the oil or at least get it closer to burning temprature.

I like this idea. (shamelessly plagurized from backyardmetalcasting.com)
I was trying to not have to use two fuels to get the thing going. It might be that I have to dump a little kerosene into the bottom of the furnace to get enough heat that I can add oil and take off. Part of me thinks that if I were to inject kerosene like a hot water pressure washer does I could get it pretty hot pretty quick and then just let the oil add to the conflaguration and go for it. I see some experimentation is in order.

Love the name of the furnace, the "scounge furnace" has a certain ring for it

it sounds as if you are under way! exciting isnt it!this preheat bit.... some scrap wood works a treat! preheating your oil is a good idea and may apply when you need to melt ....iron???? for aluminium you would nearly have your metal melted on kero!!!with just a quick blast of oil. a decent pot of aluminuim in a good furnace will take about 30 to 50 minutes!this is why i havent converted to oil yet. when i get things hot enough on wood and gas to switch to oil its time to pour! i beleive oil may be a proposition when melting brass but aluminium?????another member here was using a oil drip feed in conjunction with wood. he reported that the metal was just melted on wood and used oil to bring the melt to pouring temp!

Hmmm this may be an issue. I have an unlimited supply of waste oil, but wood to burn is sometimes hard to come by. The other thing is that in Northern California certain times of the year burning is banned due to fire danger. I can get away with my spa heater and liquid fueled appliances because they dont fling sparks everywhere. I was thinking of an electric heating element that warmed the oil almost to flash point, or to thin the oil with diesel to bring the flash point down a bit. It seems to me that the issue here is to get the body of the furnace hot enough to continously ignite the oil. I tore apart a hot water pressure washer the other day and looked at the way that the burner worked. It had a heated coil and the oil sprayed across it, bursting into flames. This of course was diesel fuel so it didnt have to be as hot. Although the heating element was cherry red. I got to thinking that if I got the element hot enough to drizzle oil over and cause fire, would once the furnace started in earnest would the intense heat of the fire melt the heating element an associated wiring. My retired father looking over my shoulder is telling me that I am making it more complicated than it needs to be and just toss a half a cup of 25%gasoline 75 diesel fuel (AKA charcoal lighting fluid) in to the furnace and toss in a match. A slight "Poof" will result and flames will be had. Put the air to it and inject oil. I am dubious that it could be that easy. Ill give it a try and make sure not to burn my eyebrows off.
more later...

why not set the furnace up wit 2 tanks one with diesel and one with W.O.
rune the diesel to get up to temp then switch to the oil?

i like your dads opinion!!! but just torching some fuel wont heat the furnace up! like you smoke is a hassle here and fire bans do occur. my solution!!!! bbq charcoal beads!!! and!!!!!! wire grid to go over the furnace...and a pound of sausages!!!! instant bbq!!! according to our laws total fire bans mean just that! except for cooking fires!!! i even roast a chicken and smoke some pork AFTER!!! ive melted!! the neighbourhood just think im having a bbq!! seriously tho ! using wood and or charcoal bbq fuel plus gas it costs me $2 to $3 per 1.5 kg of aluminium. on small molds it can take up to 5 hrs to make the molds just to receive the 1.5 kg of aluminium. i guess what im trying to say is that you dont want to spend say $5 on other fuels just so you can use some free oil???just melting 5 or 6 pounds of aluminium!!! brass maybe but not aluminium unless you are going for a major large item its possible to have a standard furnace and!!! have different burners oil/gas and just use the right burner for the job at hand!! than to make one "be all" furnace! with continued use no!!! furnace will last "that" long so after you finish your first furnace start on the next but take some time out to seek improvements in design. its a wonderful hobby and if you can build one furnace!!!???? then you can build more. after all the success ive had with casting it isnt hard to get the funding required for a second furnace once the first furnace is nearing the end of its working life!

Preheat is not difficult. I preheat with wood, and it works just fine. I don't even use that much wood, I just make sure that there is some in line with the end of my burner, dump a little rubbing alcohol on it as a starter, and light. I like to use the alcohol because it lights very easily but is nowhere near as volatile or dangerous as gasoline. When the wood is reduced to coals I turn the oil on a little at a time. The oil blows onto the glowing coals and, fire! The burner that I use is very simple, it consists of a tube within a tube, the inside tube is about 1/4" in diameter and the outside tube is 1 1/4" iron pipe. The oil runs through the inner tube and the blower air runs through the outer tube. The oil tube ends where the outer pipe ends. No atomization, the only moving part is the blower, and I get my furnace to iron temps without too much trouble. Plus, all the parts are available at a well stocked plumbing supply place. For the record, it is not something that I designed, but it works like a champ.

i like your idea for a burner odduck at your leisure is there any any chance of a pic. maybe a different thread if you like??? it sounds easy enough to me. i take it that the oil is under pressure and is sprayed into the furnace.