Sarge's Workshop
New Member
Here are some videos of my dad demonstrating an oil burning furnace, green sand moulding plus zinc casting of a spider.
Thankyou for watching!
Thankyou for watching!
Sarges Workshop - Oil burning furnace and zinc casting
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There are a lot of oil burner types out there, and everyone has their favorite.
I have found that melting zinc or Zamak, a simple propane burner with no combustion air blower is more than sufficient.
The burners that operate at red hot temperature don't hold up in the long run, and most hobby casters end up with either a drip-type oil burner, a siphon nozzle burner, or a pressure nozzle burner.
With all of these burner types, the burner tube does not get hot, and so there is no degredation over time.
Everyone swears their burner type is the best, but for fine control, the siphon nozzle or its cousin the pressure nozzle burners will perform extremely well, and are very stable.
The siphon nozzle burner operating on diesel will self-start without having to use a propane preheat, and it can be used with or without a combusion air blower (used without a combustion air blower for melts requiring less heat such as Zamak or aluminum, and with a combustion air blower to melt iron).
This is where I first saw someone using a siphon nozzle burner.
I built one similar to it, but without the propane line, since a siphon nozzle running on diesel does not need propane.
Siphon nozzles do require about 25-30 psi of compressed air to operate, which is why some use drip-style oil burners (drip burners do not require compressed air).
I tried several drip-style oil burners, and could never get one to operate with any consistency at all.
Siphon nozzle burners if used with about 10psi on the fuel tank of compressed air don't require adjustment during a melt.
You can use a gear pump designed for commercial heating units (to make a pressure nozzle burner), and it has a nozzle similar to a siphon nozzle (similar but not exactly the same).
I am in the process of converting my burner from a siphon nozzle to a pressure nozzle burner, since a pressure nozzle burner has the fine control of a siphon nozzle burner, but without compressed air being required.
Some folks just like to experiment with burners, but I prefer an oil burner that I can start and then not have to adjust during the melt, and a burner that does not get hot during operation. Preheating the oil in a hot burner generally will cause the burner to gum up fairly quickly, and it is not necessary to preheat the oil in most cases, since the furnace gets red hot. Some mix 20-30 percent diesel with heavier oil to get it to flow and burner easily, but I just use diesel, since it burnes cleanly and is not messy to handle.
Good luck with your castings.
.
I have found that melting zinc or Zamak, a simple propane burner with no combustion air blower is more than sufficient.
The burners that operate at red hot temperature don't hold up in the long run, and most hobby casters end up with either a drip-type oil burner, a siphon nozzle burner, or a pressure nozzle burner.
With all of these burner types, the burner tube does not get hot, and so there is no degredation over time.
Everyone swears their burner type is the best, but for fine control, the siphon nozzle or its cousin the pressure nozzle burners will perform extremely well, and are very stable.
The siphon nozzle burner operating on diesel will self-start without having to use a propane preheat, and it can be used with or without a combusion air blower (used without a combustion air blower for melts requiring less heat such as Zamak or aluminum, and with a combustion air blower to melt iron).
This is where I first saw someone using a siphon nozzle burner.
I built one similar to it, but without the propane line, since a siphon nozzle running on diesel does not need propane.
Siphon nozzles do require about 25-30 psi of compressed air to operate, which is why some use drip-style oil burners (drip burners do not require compressed air).
I tried several drip-style oil burners, and could never get one to operate with any consistency at all.
Siphon nozzle burners if used with about 10psi on the fuel tank of compressed air don't require adjustment during a melt.
You can use a gear pump designed for commercial heating units (to make a pressure nozzle burner), and it has a nozzle similar to a siphon nozzle (similar but not exactly the same).
I am in the process of converting my burner from a siphon nozzle to a pressure nozzle burner, since a pressure nozzle burner has the fine control of a siphon nozzle burner, but without compressed air being required.
Some folks just like to experiment with burners, but I prefer an oil burner that I can start and then not have to adjust during the melt, and a burner that does not get hot during operation. Preheating the oil in a hot burner generally will cause the burner to gum up fairly quickly, and it is not necessary to preheat the oil in most cases, since the furnace gets red hot. Some mix 20-30 percent diesel with heavier oil to get it to flow and burner easily, but I just use diesel, since it burnes cleanly and is not messy to handle.
Good luck with your castings.
.
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Sarge's Workshop
New Member
Thankyou for your comments. I'd like to add that we didnt use propane, we will in future attempt to melt iron which we have achieved already with solid fuel using blacksmiths nuggets in our small foundry.
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I've cast a fair amount of ZMAC and just use a Hot Pot, or a lead pot made for casting bullets etc. Electric, no muss no fuss and easy to use. ZMAC is under appreciated, easy to cast, nearly as strong as cast iron and makes excellent bearings. Kind of heavy though. I use segmented aluminum molds as described in MEB years ago.
I heard that zinc or so called pot metal castings got a rap early on because they were using an inferior alloy that degraded over time. I think the new alloys with aluminum are very good and stable. Melts around 800 degrees f.
I heard that zinc or so called pot metal castings got a rap early on because they were using an inferior alloy that degraded over time. I think the new alloys with aluminum are very good and stable. Melts around 800 degrees f.
Sarge's Workshop
New Member
I'm only melting zinc because I have a lot of it, and im trying out the burner. The spider is an ornamental item but later I will cast more interesting pieces in all other types of metal. I am experimenting with different nozzels and jets for complete combustion of fuel and air.
One more comment: Most people (myself included) make/made the mistake of trying to force too much combustion air and fuel into a furnace, with the idea that more is better/hotter.
The hottest temperature you can achieve inside of a furnace is when you introduce the maximum amount of combustion air and fuel into the furnace that its surface area can completely burn as it passes through the furnace.
Any more or less fuel/combustion air introduced into the furnace actually makes it operate cooler.
Finding the optimum maximum air/fuel rate for your furnace size for full combustion inside the furnace is critical when meltin iron.
When melting zinc or aluminum, a widely out-of-tune burner will still work fine.
It took me quite a while to figure this out, and so I share it in hopes it helps others save some time.
.
The hottest temperature you can achieve inside of a furnace is when you introduce the maximum amount of combustion air and fuel into the furnace that its surface area can completely burn as it passes through the furnace.
Any more or less fuel/combustion air introduced into the furnace actually makes it operate cooler.
Finding the optimum maximum air/fuel rate for your furnace size for full combustion inside the furnace is critical when meltin iron.
When melting zinc or aluminum, a widely out-of-tune burner will still work fine.
It took me quite a while to figure this out, and so I share it in hopes it helps others save some time.
.
100model
Well-Known Member
It is easy to melt iron with oil, also it is easy to melt iron with propane as well but oil is free but propane is not.
Melting iron with propane is easy if............you either have a large propane tank, or can keep a smaller tank up to ambient temperature in a water bath or by some other method. The problem with propane is that at the flow rate required to melt iron, using a 20 or even 40 lb tank, cools the tank very quickly, to the point where the propane will not change from a liquid to a vapor, and so your pressure keeps dropping off, and the melt goes cold.
I tried several schemes to try and get consistent propane melts, and finally kicked propane to the curb, for iron melts anyway.
I still use propane for smaller aluminum melts.
Using oil to melt iron solves a lot of fuel problems.
I have used diesel down to perhaps 35 F, with no problems starting or operating the burner.
100model is correct though, propane is fully capable of melting iron, if you can maintain the tank output pressure/flow.
Safety is another factor, and I feel safer if I break an oil line than I do a somewhat high pressure propane line.
Oil puddles on the ground, and does not really ignite easily on the ground.
A propane leak can make for a big surprise, and there is no visible indication that the propane is leaking.
.
I tried several schemes to try and get consistent propane melts, and finally kicked propane to the curb, for iron melts anyway.
I still use propane for smaller aluminum melts.
Using oil to melt iron solves a lot of fuel problems.
I have used diesel down to perhaps 35 F, with no problems starting or operating the burner.
100model is correct though, propane is fully capable of melting iron, if you can maintain the tank output pressure/flow.
Safety is another factor, and I feel safer if I break an oil line than I do a somewhat high pressure propane line.
Oil puddles on the ground, and does not really ignite easily on the ground.
A propane leak can make for a big surprise, and there is no visible indication that the propane is leaking.
.
100model
Well-Known Member
This is why the bad smell is added to propane so leaks can be detected.
