Eough BTUs ?

[mran1126]

I saw a propane single burner cast iron base. It puts out 15,000 BTUs. I was wondering if that is enough for smelting and casting? $26 plus freight.

[grumman581]

That is a bit light compared to what some people are using for smelting, but it will probably work. It's going to depend upon how large of a melting pot you are going to use. One thing that you can do though is remove the regulator and use the propane tank's valve to control the flow rate of propane and you can probably get a lot more BTUs out of it. If not, then you just need to increase the size of the gas jet in the burner. I usually drill them out to 1/16" for using natural gas. For that kind of money, you might be able to find you one of the turkey fryer / crawfish boiler burners that have quite a few more BTUs. For example:

http://www.academy.com/images/products/220/0267/0267-01781-0090-p1.jpg
110,000 BTUs -- $39.99 -- http://www.academy.com/index.php?page=content&target=products/outdoors/grills/fryers&start=0&selectedSKU=0267-01781-0090

http://www.academy.com/images/products/220/0262/0262-01287-0002-p1.jpg
160,000 BTUs -- $24.99 -- http://www.academy.com/index.php?page=content&target=products/outdoors/grills/fryers&start=0&selectedSKU=0267-40037-0002

There's also ones like this for $29.99, but it doesn't say how many BTUs... Probably 50,000 or so from the look of it.
http://www.academy.com/images/products/220/0267/0267-02367-2518-p1.jpg
http://www.academy.com/index.php?page=content&target=products/outdoors/grills/fryers&start=0&selectedSKU=0267-02367-2518

Kind of strange that the higher BTU unit is cheaper than the lower BTU unit...

Another option that you might want to consider if you are really wanting to over-engineer the burner's stand is to make it yourself and just buy the burner itself from a company. For example, the Bayou Classic BG10 burner goes for $16.99 here:
http://www.perfectestores.com/index.php?main_page=product_info&cPath=258&products_id=3616
http://www.perfectestores.com/images/Bayou-Classic-Hig.jpg

According to the bottom of this page, the Bayou Classic BG10 is 150,000 BTUs.
http://www.amazon.com/Bayou-Classic-BG10-Cast-Iron-Replacement/dp/B0009JXYSW

Now, if you REALLY want to get serious about it, there is this little 210,000 BTU unit. It's called the Bayou Classic BG14 and goes for $44.99.
http://www.perfectestores.com/images/Bayou-Classic-Cas.jpg
http://www.perfectestores.com/index.php?main_page=product_info&cPath=258&products_id=3611

Kind of strange that this company is wanting more for this part than you can get it from the manufacturer. Usually, ordering from the manufacturer is more expensive. The manufacturer has it for $39.99:
http://bayouclassicdepot.com/bg14_cast_iron_burner.htm

Or $37.99 here:
http://www.hobbywarehouse.com/Products/Propane-Cast-Iron-Burners/10-Banjo-Burner-w-Air-Shutter-Spring?cvsfa=1414&cvsfe=2&cvsfp=BG14

I'm using a burner fairly similar to that, except I'm using it with natural gas and as such, I'm pretty sure that I'm not getting anywhere close to that many BTUs, but it works well enough for the amount that I'm smelting.

Anything worth engineering is worth over-engineering...

[cajun shooter]

15,000 btu is the same as a large burner on a gas range. Buy a outdoor burner as posted above. YOU DON'T need a gizzillon btu to reach the melting temp needed though.

[Ron B.]

Good morning guys!
Boys, IMO when it comes to casting you just can't have too many BTUs.

Grumman, you covered things very nicely. I almost bought one of the ones you mentioned. Cabela's had a KING KOOKER package for $99.95 I went for. Yes, at first it appeared pricey. But, after looking at everything, it's an OKAY Package. Not only did I get a 100,000 plus BTU stove, but regulator and hose, and a really nice pair of gloves! I actually just received my package last Thursday, putting it to work Friday casting over 700 lbs of lead. What I really like about it is, the hose supplied has a user regulated regulator. Casting for about 7 hours straight, the unit used about 10 lbs of propane. Or, half a small bottle. Here's the link, if interested to Cabela's.

http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?_DARGS=/cabelas/en/common/catalog/item-link.jsp_A&_DAV=MainCatcat602009-cat20079-cat20122&id=0031808516768a&navCount=4&podId=0031808&parentId=cat20122&masterpathid=&navAction=push&catalogCode=IK&rid=&parentType=index&indexId=cat20122&hasJS=true

[GLL]

Propane contains 92,000 BTUs/gallon. Propane weighs 4.2 pounds /gallon. Some simple testing has shown me that many of these burners are very over rated in how many BTUs/hour they are capable of !

My 60,000 BTU/hour high pressure burner produces twice the output of a couple rated at 160,000 BTUs/hour when measured in propane consumption ! Many sellers simply put an inflated rating on as a sales gimmick !

Set your propane tank on a scale while you use the burner and watch the rate of weight change . My 60,000 BTU rated burner actually produces only 55,000 BTUs/hour. The 160,000 BTU burner I tested was only about 30,000 BTU/hour but it worked just fine !

It is probably best not to worry too much about the ratings we see in the store. If the burner works to our satisfaction then go for it ! :) :)

Jerry

[grumman581]

My 60,000 BTU/hour high pressure burner produces twice the output of a couple rated at 160,000 BTUs/hour when measured in propane consumption ! Many sellers simply put an inflated rating on as a sales gimmick !

Here are some of factors in how many BTUs that you are going to get out of a burner.


pressure of the gas from the regulator to the jet
size of the jet (orifice)
total area of all the burner holes


#1 combined with #2 tells you how much gas you potentially have available to burn. There is a formula that calculates this, but I'm too lazy to look it up right now. You want #3 to be quite a bit greater than #2 so that the velocity of the gas coming out of the burner holes is less and as such, the flame will not be as high. If you turn fully open and you have a considerable distance between the bottom of the flame and the top of the burner, you probably do not have enough burner hole area. You either need to increase the diameter of each of the holes or need to add more holes. You want the height of the flame to be such that the hottest part of the flame is touching the bottom of your pot. Some people add a piece of metal around their pot to recover some of the heat of the flame for the sides of their pot. This also helps keep the flame steady if your are smelting outside and there is any wind. Redesigning your stand so that that it is more difficult to knock over might be a good thing since you're looking at perhaps 60 lbs of lead in even a normal size cast iron camp stove / dutch oven and if it gets knocked over, the penalty tends to be rather severe with respect to possible medical bills. Spend a little extra time and do it right.

[Ron B.]

A question; you guys appear really knowledgable, regarding propane cookers.

Do you want one really hot flame; or a multiple of smaller flames? My King Kooker shoots one really hot flame. It's adjustable through both the regulator (knob); or the propane tank itself.

IMO, wind is a huge factor; robbing your heat. It's the reason I do my smelting in the confines of my garage. Well ventilated; of course.

GRB

[grumman581]

A question; you guys appear really knowledgable, regarding propane cookers.

Do you want one really hot flame; or a multiple of smaller flames? My King Kooker shoots one really hot flame. It's adjustable through both the regulator (knob); or the propane tank itself.

IMO, wind is a huge factor; robbing your heat. It's the reason I do my smelting in the confines of my garage. Well ventilated; of course.


For me, it was probably a misspent youth in college engineering courses... :-)

For a little light reading, refer to this URL:
http://www.air-dispersion.com/msource.html

30-something years ago, this probably made sense to me... Hadn't used it since then, so I'll refrain from straining my brain cells today...

I think that the multiple smaller flames is more efficient than the one really large flame. Technically, they are both probably the same temperature. You can only get so hot with propane or natural gas mixed with air. For propane, it is 1995C and for natural gas, it is 1950C -- more than enough to melt lead or even zinc. Hell, it's even enough to melt thick aluminum (personal experience from over-engineering a BBQ grill burner without considering that the cast aluminum enclosure also needed to be re-engineered). The heat that is produced from the flame works to heat the lead in the pot. Of course, we don't have a 100% efficient system here -- some goes into the pot to melt the lead, some escapes around the side of the pot, some is radiated out of the side and top of the pot. Any wind that you add to the system also robs you of heat that you are trying to put into the system by blowing the flame away from the bottom of the pot or subtracts from the heat already in the system by facilitating more rapid cooling of the pot. I would suspect that a higher velocity flame is going to be less subject to the affects of wind on it. I use natural gas through my burner and it is definitely affected by wind -- enough so that I try to be on the leeward side of my garage when I'm smelting. I'll probably consider building a flame shield before I do my next smelting on a windy day. I'm thinking of just getting a piece of large diameter pipe that is about the diameter of my smelting pot (which has a larger diameter than my burner) and which is long enough to just sit on the ground and still come up high enough to be at the top edge of my smelting pot. Of course, I will probably need to cut a few air holes in the bottom, but this will be somewhat depended upon whether the pipe is of large enough diameter to cover the air mixture vent on the burner.

[Charlie]

I saw a propane single burner cast iron base. It puts out 15,000 BTUs. I was wondering if that is enough for smelting and casting? $26 plus freight.

I use a 10,000 BTU/hr rated Coleman single burner propane camp stove and about a 2 qt stamped steel sauce pan. Fill the pot with muddy jacketed bullets from the backstop and after you spoon out the jackets and dirt it will yield 10 lbs of lead in maybe 15 min of melt time, outside in the open. Right now I'm experimenting with small batches so I don't much capacity but this should give you some idea of what 10,000 BTUs/hr can do.

[94Doug]

Probably a stupid question, but doesn't the intake of air along with the propane also up the heat as well?

[mran1126]

Thanks for the replies. I was wondering about the 15,000 BTUs because I know a lot of you use Coleman camp stoves as a heat source. I didn't know how many BTUs they put out. Ace Hardware has one of the larger burners for $36.95. Maybe I'll take a look at it.

[grumman581]

Probably a stupid question, but doesn't the intake of air along with the propane also up the heat as well?

When they quote the number of BTUs in a pound of LPG (propane), they are probably assuming a default oxygen concentration for the environment that it is being burned in. I looked on the web, but couldn't find how it is defined. If it was defined as the maximum with 100% O2, then that would explain why the ratings for burners does not equal the fuel used. Hmmm... This has got me curious... I think I'll have to look into this a bit more...

[94Doug]

The reason I ask is that the burners have the air intake on them now, and when you open the gates, the thing really roars!

[grumman581]

The reason I ask is that the burners have the air intake on them now, and when you open the gates, the thing really roars!

LPG needs a certain amount of air (oxygen, actually) to burn. If you don't have the mixer gate open, it is going to mix with air after it comes out of the burner nozzles. Since it is too rich at that point, it is going to have to get further away from the nozzle before it has mixed with enough air to be of the right percentage to burn. If you premix it with oxygen, then it can burn closer to the burner nozzles -- that is what the gates are allowing to happen. You also want the speed of the gas to be enough that it is burning outside of the burner nozzle instead of inside it. Each gas has a particular flame speed that affects this.

Here's a pretty good article that explains it fairly well:

http://www.propanesafety.com/Resource%20Library/Gas%20Check/CETP%206.0%202001%20Gas%20Check%20Cross%20Referenc es/NPGA%206.2%20(III).pdf