naturally aspirated burner

Check out the brute oil burner. Lots of images on google. Hotshot is the other proven drip oil burner. They are just what OIF and others are talking about.
https://www.backyardmetalcasting.com/
Both will require preheating, propane being easiest. You have mentioned the possibility of upping your furnace size since you got a sizable amount of refractory so your question about economy becomes more pertinent. A small highly insulated furnace like Fishbonz describes will probably get you as hot as you want with propane pretty cost effectively. Ironsides has demonstrated cast iron melting in a similar furnace. Even a larger bore refractory furnace with less aggressive insulation can run brass reasonably cost effectively on propane only, for sure. But something like a 30 or 55 gallon size with high mass? Oil time. Frosty propane tanks suck.
My bigger furnace is in a half keg 10"bore. 1" Mizzou backed up by 2" of sand/fireclay. I can get my bore red hot in about 15 minutes. But when I switch over to oil (waste, kero, diesel, pick your poison), it turns into a completely different animal. I could have and maybe should have selected a better insulation strategy but I certainly have enough firepower. I'd go broke running propane only.

 

That's certainly less work than hauling out a 100ft extension cord.

 

That's what I was thinking if I upgraded to a bigger one I would need a cheaper fuel source. I think I will stick with this one for a while to give me more time to prepare the rest of the stuff I'm gonna need to start. Thanks!

 

This is one of the examples of why different people use different equipment.

Billy: Are you hearing that the dense refractory costs you a lot of fuel, and that a lightweight furnace heats up quicker and costs much less fuel? My brick furnace is lightweight and I can get a No. 6 crucible aluminum pour ready in 35 minutes. Lighter insulation heats quicker.

Surely you have some friends who change their own oil. Everybody has trouble getting rid of it. An aluminum melt usually costs me about three quarts of oil. I pour anything that will burn into my tank: motor oil, contaminated diesel fuel, stale gasoline, transmission fluid, gear grease, strained cooking oil, any hydrocarbon I drain goes in. No antifreeze or water.

Here's my burner:



Oil comes in the right angle needle valve and out the brake line in the foreground, left picture. Propane goes in the line with the quick disconnect. Yellow knife gate controls the air flow which goes in the end closest to it. There's an o-ring around the pivot bolt under the double nut so it stays put but can be moved. Handle was lost foam cast to resemble an old refrigerator handle. It all stays cool because of the air flowing through it. That burner has at least 200 hours of run time, maybe 300.

 

No, you do not have to "run your fire" widdershins. (Counter Clockwise)

Unless, of course, you are a (fictional!) witch, and are casting fetishes for the witch-trade...

I've written about this at some length: www.slowginonline.com

 

At length??? Is that what you call that? ZAPS THESIS was shorter than that!
Which chapter has the kinky stuff????

 

Seeing Jeffs video again makes me want to steam punk the piss outta my oil burner. How cool would that be? I could outfit it with stupid gauges, led lights, and even a speeder spring and fly weight governor rig on top! It would need a steam whistle of course!

 

Some people do like to go all out. We had one individual in the patternshop who spent two weeks developing a new gating calculator that took every factor he could think of into account...including the sand conditions which change on an hourly basis. It never really worked for him.

 

4 full size novels (one of which is over a thousand pages) and about half of a fifth. Figure at least 2500 pages.

Not sure if there's any, uh, "kinky stuff" present.

There IS foundry stuff, though. Is that "kinky?"

 

lmao... That's a lot of writing! You get anything published yet?

 

Supposedly, that requires an Agent. I have no idea how to get one without getting a complete brain-transplant first. I have heard about self-publishing, but again - get a complete brain-transplant first.

Oh - and what's present there is but the tip of the iceberg. There's about seven to ten times that much in various levels of Draft.

 

Update....yesterday I decided to build an oil drip burner. I built it and used an old bathtub jacuzzi blower as the blower. It can be timed and set at different levels. I did a brass melt with propane and cut my melt times more than in half on low and about 15 psi. I will hook up the oil tank and oil during the week for some testing. I will post videos and probably start a new thread on the build. I did have to modify my lid. I pulled the refractory out and replaced with wool but still had the same effect.... the hole will need to be bigger than 3 inches. I used wool as a lid and folded it so the flame could come out four side and the top. Freaking awesome!

 

Billy, Three inch vent should be plenty for a propane tank furnace.
In my opinion, you're trying to run your burner too hard. There is only so much room in the furnace for combustion.
All your posts are about speed. I got caught up in that when I first got started. My castings suffered because of it.
Take a deep breath and relax, turn your burner down to what the furnace can actually handle.
Now a days, I'm more proud of how many melts I can get out of a 20 lb tank than how fast I can melt.

 

Not sure why you think it was all about speed but the whole goal was to improve efficiency.. I have been running test with different burners and commenting on the results. Some have had great success at low gas psi and are amazingly efficient for aluminum. In fact one of my post I had talked about only having a three quarter of an inch vent while running at 3 psi of gas and melting aluminum rather quickly. That is about where the efficiencies stopped. To get to brass and cast iron temps you must run higher and the three inch vent does not allow for that...at least not easily. I am doing the test to get the most efficient cast iron and brass melts as well as aluminum. I have discovered that no matter which burner you use with propane and no matter what setup you use, propane will cost you too much money to melt brass and cast iron very often. Hence the oil burner for cast iron and brass. I m not a fan of wasting gas by blowing it out the vent hole...as I have mentioned many times before but in order to melt cast iron I will have to take it up a notch.

 

I usually melt 14 Kgs of iron at a time, so if I use propane 8.65 Kgs is burnt and if I use diesel 8.1 Kgs is burnt. You should be able to do a cost analysis from those numbers.

 

Lord I would have to do those conversions to gallons and compare to our domestic rates. Lol I have now learned that clean fuel is not a necessity. I will be using what I can find free now. I think...not sure but believe the propane would be cheaper according to your rates of kg per melt. That is pretty interesting .. I would have guessed the propane would have been way more expensive to operate but not at that rate. I also thought it would take much less oil/diesel for the same melt so that too is interesting. I will monitor mine with different fuel sources when I get it all finished and share them on here. I only have the propane on it now but will attach waste oil line later. I also may have to reconsider how many melts I can do at that rate. On my ten gallon I have several aluminum melts and two brass melts...well I had to change tanks on second melt because it froze but is almost empty so I will just leave it off. I rotate three small tanks because they refused my large tank last time because it has the old valve. I only filled it there a few times before and they never cared..so..oh well. Thanks for sharing!

 

Interesting that your rate of fuel/kg iron is very close to mine. I am usually melting a 25 to 30 kg but the ratio is nearly the same. We must have both tuned to about the same point.

Denis