naturally aspirated burner

Diesel fuel. It is one of the safest fuels with the highest BTU hands-down. It's consistency is pretty good at a wide range of temperatures. When I'm using waste oil, I need to plan ahead about four hours using a small 200W block heater attached to the tank.

It is absolutely pleasurable when using waste oil when you get it for free I. But I like to flush the lines with diesel fuel at the end of the run.

Propane might be a little bit cleaner, as it becomes a gas. But, in my opinion propane is a waste of money and is just convenience. For larger melts of A6-8 copper, brass or even cast-iron Diesel fuel, Home heating fuel or waste jet fuel is the way to go. Once the furnace has achieved over 5-600°F, switching to a waste oil is very easy but temperamental. I have got rid of the temperamental by preheating the waste oil to 50 to 60°C. But, I pressurize my tanks diesel and waste oil to 40 psi for delivery. I do this with a miniaturized homemade air compressor made from an old refrigerator compressor. The compressor cycles for about 15 seconds every 3-4 minutes.


I also use also 7 psi 4 stage turbine or a 5 psi single stage ring compressor to deliver combustion air. Both of them deliver a lot of air, and can be throttled.

A good blower could be as simple as an air mattress blower. But, you will want a big delivery pipe to compensate static restrictions. This is why I have powerful blowers as my delivery lines for combustion air or garden hoses.

 

I used propane for about a year until I realized it was going to send me to the poor house melting cast iron. Waste oil does not cost anything but using it in the colder months requires about 10% -20% diesel addition so the oil will flow fast enough to the burner. I did a comparison between 100% diesel and 10% diesel and waste motor oil and there was no difference in melt times and the amount of fuel used. If I melt bronze in my furnace is uses twice the amount of fuel to melt aluminuim and cast iron requires nearly four times the fuel used to melt aluminuim. To reach cast iron pouring temps requires a lot of air and fuel because at higher temps with smaller furnaces a lot of heat is lost. This is why I get endless emails asking why their furnace will not melt or get hot iron. Most times they have a furnace that melts aluminuim and brass but will not get much hotter. Think of the wind resistance on your car, to get it to go twice maximum speed you have to increase horsepower maybe four times and streamline for less wind resistance.

 

Where I live in Australia propane costs a lot more than diesel and I think you would be right, propane would be nearly twice the price as diesel. If I want cheaper propane I need to hire a 200 Kg propane tank and a tanker comes around to fill it up. Since I have gone to waste oil I use a 45 Kg propane bottle and that last me for years between refills.

 

In Canada, to fill a 20 pound propane tank it is almost 1 dollar a pound, or about $20. Diesel fuel is about 1/4 per $1 about .22 pounds per litre. So, at the same purchase price you would get 24.4 litres of diesel for 1/4 price as propane. But diesel fuel has aboat 10% more BTU pound for pound add a cheaper price.... If you are implementing waste oil, the burn now becomes free.

 

Diesel in southern Ontario where OMM is, is currently about $1.05Cdn/L, a little less if you have access the the dyed fuel intended for farmers and other off-road users.

 

I got some huge news this morning! I have been granted all the waste oil that we produce here. Roughly 350 gallons every 3 months or so. Going to go set the 55 gallon barrel in place so he can start pumping today! I can get straight oil or get hydraulic fluid mixed in as well. Anyone know which would have better results?

 

I knew somebody would do all those conversions eventually.LOL

 

Runny (lower viscosity) fuel tends to flow easier - and tends to atomize more readily, also.

Hydraulic fluid tends to be runnier than used motor oil. Diesel fuel is more so still, hence the plan is to get two or three "catch-all" yellow containers for used oil (at the big_furnace site), and the request to fill them one-third full of diesel fuel prior to adding oil...

 

They misspoke about what is in it. It is atf and not hydraulic fluid. I don't think it will matter though. Thinner is better for cold weather.

 

I went back and read. Oops. I missed a few words I was trying to say you get 1/4 less BTU for the same price in my area. But in reality it’s A little more than a 1/3 less BTU for the same price. And if you do the math the other way A 20 pound propane tank to $20 with a diesel you get 155% more BTU.

-A 20 pound propane tank has about 17.8 L in it which cost about $20 Canadian. 17.8 L of propane has 392 685 BTU.
-20 L of diesel fuel costs $20 Canadian. ($1/L) (36.6 pounds) 20 L of diesel fuel has 609,780 BTU.

https://www.extension.iastate.edu/agdm/wholefarm/pdf/c6-87.pdf

 

I was talking to my foundry guru about propane vs diesel, he mentioned that years ago he had some kind of tax free permit for foundry diesel fuel as it was not being used for road vehicles. Currently that would make it 64 cents per litre Australian for diesel which would be US $1.76 per US gallon. For the 64 cents per litre price, I asked a fisherman what he was paying for diesel as it's tax free for them. It seems to be a horribly complex system of excises and then taxes on top of the excise but seems to be 42 cents Australian per litre excise with a 10% goods and services tax on top of that.

 

Free jet fuel all the way! Propane is for youtube wankers running their Devil forges pouring useless ingots.
If my source drys up, I'll burn cheap diesel. I just hate getting the propane tank filled up and it would be a major disaster to run out mid melt! You only do that one ONCE!

 

LOL..I actually did...well it froze and stopped putting out before it should have...did suck indeed but I had another handy so no biggie...just had to switch it out real fast. I like the cleanliness of propane much better for sure but can see it getting expensive as often as I hope to be able to melt on a more regular basis soon. I would think the jet fuel would be awesome but still not as clean as propane. I dont think what I am about to venture into will be clean at all. But shit Im used to it and Im a tight wad...plus I havent sold anything I have made. I actually have given everything I have made away or found somewhere to hang it myself. Im in no way artistic...probably dyslexic in my art skills so I am lucky to find someone who will take it.LOL

 

Jet fuel and diesel burns pretty clean. Even dirty nasty old use motor oil will burn clean. It's the storage of it that can get messy. I would never burn anything other than natural gas indoors and even then, good ventilation is critical. One of our guys here recently bought the farm from lack of O2.

 

Right now I am able to melt in my building with no issues but that might change with the waste oil burner. I am planning on building a bigger furnace anyway and will probably make it outside the shop but build an overhang to melt under.

 

Yeah, outside is a good idea.

 

Anyone else notice phones recently seem to be royally screwing up when typing stuff? I get dropped words, goofy spelling and just all sorts of weird crap!
I was saying... We dodged a close call here recently and almost lost one of our members who was melting indoors. Anyways, worth repeating during these colder times.
I run an un-vented natural gas heater in my garage. These should never be used in areas where you SLEEP!
I use this thing to take the chill out of the garage while working out there. After a couple of hours, I'll open/close the garage door, just to get some fresh air in.


And no one say a damn thing about the garden hose feeding my chinese heater either!
I don't do any blacksmith crap in the winter, so I clamp the heater in the vise. In another month, it will go back up into the attic.
The fan on the wall does a good job spreading the heat around.

 

For shop heat, I use a 30,000 BTU natural gas overhead radiant tube heater. My garage doors have an insulated value of R 12. The rest of my exterior walls are R 20. I keep my garage shop at 70°F when it is 0°F and I also keep it that 70°F when it is 95°F with air-conditioning.

My natural gas tube heater. This heater is 10 foot long in a U-shape. It has about 2 inches clearance to the drywall ceiling. The nice thing with my system, all burnt gases get exhausted to the outside. The nice thing is, No carbon-monoxide exchange fumes in the work area.