instructables
How to Make a BBQ Burner
by MaxPower1977
For a DIY griddle project I'm working on I need a But a warningfirst, playing with propane is propane burner that will heat up the cooking surface, I dangerous, so if you decide to try this you do so at thought the build of the burner would make a good your own risk and peril. At minimum wear safety Instructable. Buying a burner was out of the question glasses, gloves and non-flammable clothing. Also do as the size and power I require is not available of the this in a very well ventilated area, outside or in an shelf. If you need to replace or repair a BBQ burner open garage, you don't want carbon monoxide this might help you as well. poisoning.
How to Make a BBQ Burner: Page 1 Step 1: Materials and Tools
This is what I used but other materials could be used as well depending on the application:
1" x 1/16" stainless steel tubing (could substitute this with regular steel but stainless will last longer) 3/4" to 1 1/2" black iron reducer fitting 1/8" brass NPT pipe nipple 1/8" brass NPT end cap 1/8" ball valve rated for gas 3/4" steel bar stock Low pressure BBQ regulator and hose (depending on how many burners you hook up you will need to increase the capacity of the regulator) Flare fitting to go from the propane hose to 1/8" NPT thread Propane Tank PTFE tape or pipe dope
Tools:
Drill and Drill bits Small Drill bits (1mm or 1.2mm) - you can get a set off amazon if you can't find them locally Tap and Die set (8-32 tap and 1/8" NPT tap) Welder with cast iron welding rods or MIG Welder with stainless steel wire (this makes things easier but it is possible to braze the parts together as well with a propane torch) Bandsaw or hacksaw Center punch Angle grinder with cutting disc
How to Make a BBQ Burner: Page 2 Step 2: Theory and Design
So lets talk about theory, at least in my layman's terms:
This burner design works off the venturi effect, as gas is being forced out through a small orifice mounted at the end of the burner, it pulls air along and mixes inside the burner tube. The mixed propane and air then is forced out of the burner holes or slots and when ignited it burns.
Propane needs to mix with air to burn at a specific ratio, but with trial and error I was able to get the burner to burn with a nice blue flame. If you get a flame with yellow or orange, it means that there is un-burnt fuel and not enough air has mixed with the propane to get proper combustion. The size of the orifice hole is very critical to the size of the tube, if the tube is too small and the orifice hole too large you get incomplete mixing and incomplete combustion.
For this design I tested many different orfice holes, from:
1/32" - too small - very small blue flame 1/16" - too big - lots of yellow but a very powerful flame 0.8 mm - too small 1.0 mm - just right - no yellow flame 1.2 mm - just right with a bit of yellow but a very strong flame
I landed on a 1.2 mm orifice hole.
Step 3: Video of the Construction of Burner
Check out the video for how I build the burner, the written steps follow:
//www.youtube.com/embed/ar6NGXjNRJI
How to Make a BBQ Burner: Page 3 Step 4: Orifice Assembly
The orifice assembly is made from
1/8" brass NPT pipe nipple (length is dependent on the application) 1/8" brass NPT end cap 1/8" ball valve rated for gas 3/4" steel stock
The center of the 1/8" brass NPT end cap was center punched and then drilled out using a 1.2mm drill bit, cutting oil was used too. This hole is the orifice and propane will flow out from this hole at high velocity.
Also pro-tip, if the drill bits are too small for the chuck of your drill use some metal tape and wrap it around the drill bit so it will make the shaft large enough to be grabbed by the chuck.
Center punch the 3/4" steel stock and drill a hole that corresponds to the 1/8" NPT tap. Using lots of cutting oil cut threads into the hole. This hole will thread the 1/8" brass NPT pipe nipple. Once the pipe nipple has been threaded through the hole, cap off the opening of the tube with the cap that has the orifice hole drilled in from a previous step.
Thread the ball valve onto the other end of the nipple. Be sure to ensure a leak free seal between all the fittings by using PTFE tape or pipe dope to seal the threads.
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1. 1/8" NPT Tap 1. 1/8" NPT Tap 2. 1/8" NPT short pipe nipple
How to Make a BBQ Burner: Page 4 1
1. 1.2 mm hole drilled into 1/8" NPT brass cap
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1. The assembled unit
How to Make a BBQ Burner: Page 5 Step 5: Building the Burner Tube
The body of the burner is made from a piece of this could be brazed and the holes could be tapped stainless steel tubing, stainless is really hard to work directly into the end of the reducer fitting. I chose to with as it work hardens. I first was going to drill burner weld on some tabs as it made it easier to work with. holes in it but it would take far too long and far too much work so I decided I would cut small thin slots in A note about welding the black iron reducer fitting: the tube spaced 1cm apart for the burner "holes". I these fittings are typically cast iron which do not weld used my portable bandsaw and made short work of very well or easy. Since I am just tack welding, it's not this but a hack saw could be used too. really an issue, also the cast iron should be preheated before welding. I am using a MIG welder The end of the stainless steel tube was heated and with stainless steel wire, which I have heard that can then bent closed in a vice. This allows the burner tube be used to welding cast iron. So far I have had no to be crimped and "capped" off, making a flat spot issues with cracking. A nickle welding rod can be where a hole can be drilled and used for mounting the used too. burner. The end of the tube was welded shut after crimping (this could be brazed as well). Line up the orifice of the orifice assembly so it's in the middle of the 1 1/2" opening of the reducer fitting, you Next the tube was welded on to the 3/4" to 1 1/2" want the propane to shoot straight down the burner black iron reducer fitting, the reducer fitting makes for tube so it can mix with air, clamp in place and mark a great burner intake for air and mount for the orifice. the holes with a marker. Holes were drilled into the Two 3/4" steel tabs were welded on to the sides of orifice assembly that match the steel tabs with the the reducer that were tapped with a hole (3-32 bolts is tapped holes so the orifice assembly could be bolted what I used) to accept a bolt for mounting the orifice to the reducer fitting. assembly. Again if you don't have access to a welder
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1. Slots were cut into the 1" stainless steel tube. 1. Slots cut 2. End was heated and crimped shut in a vise.
How to Make a BBQ Burner: Page 6 1
1. The crimped end was welded closed.
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1. 1 1/2" to 3/4" pipe reducer had tabs welded on each side.
How to Make a BBQ Burner: Page 7 1
1. The tabs were tapped to accept a 8-32 bolt.
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1. Cast iron was preheated to prevent cracking before welding.. 1. Tacked welded in place.
How to Make a BBQ Burner: Page 8 1
1. Stainless steel wire was used or a nickle based rod for cast iron.
Step 6: Hooking It Up and Testing
To hook up the burner to the propane I used a fitting before testing. that went from the flare fitting on the propane hose and regulator to 1/8" NPT threads, in my case the ball Turn on the propane on the tank and open the ball valve. This will depend on the fitting you used so just valve 1/4 of a turn ,you should hear gas flowing, using use what I have done as a guideline, check your local a BBQ lighter ignite the gas flowing from the slits cut area for a propane supplier or fitting shop and they in the burner tube. The whole burner should light, if it will be able to get the proper fittings for you. doesn't turn up the flow of gas. There should be a nice blue flame if everything is working properly. The propane regulator I used was low pressure one Trying adjusting the flow of gas and see if the flame is for a BBQ, it needs to be large enough to handle the burning correctly, it should be blue when turned up capacity of the number of burners, in this case I sized low or high. If it isn't try changing the size of the this regulator to 80,000 BTUs, more than enough. It's orifice or the position of the orifice assembly. better to have excess capacity than not enough. Remember the flow rate of the regulator is different With this design one could make a large burner than the pressure it can provide. Low pressure provided you find a tube that is large enough to allow propane regulators (less than 1 psi) are very common for proper mixing of the propane and air. Also and are plain gray or silver in color, a high pressure remember a stainless steel burner tube will outlast regulator is red in color. An adjustable high pressure regular mild steel but mild steel can be used as well regulator could be used as well but it depends on how especially if you are doing a proof of concept. forceful you want the flame to be. Good luck and be-careful! Clamp the burner securely into vise or table
How to Make a BBQ Burner: Page 9 1 4
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1. Low pressure propane regulator (less than 1 PSI) 1. Ball valve to control the flow of propane. 2. Incoming propane from regulator. 3. Flare fitting 4. Long pipe nipple used for testing.
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1. Good blue flame show proper combustion.
How to Make a BBQ Burner: Page 10 1
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1. Here is a series of burners plumbed together. 2. Flare fitting.
FIRST OFF. Heating galvanized coating and oxidizing the zinc WILL KILL YOU, if you breathe in much. There are tables online that will give you the size of the orifice (hole for propane to go through) for a particular BTU value at a given pressure. Also other people might want to consider putting a shutter on the air intake to adjust the air flow to set the air flow to match the orifice size rather than trying to make the orifice size match the air flow.
One thought for anyone working with propane. It is a heavier than air gas and tends to pool in low places if there is not any air moving. So if you do plan on trying this make sure that you have some moving air and no low places where the gas can collect and then go BOOM at the first spark. I had a pool heater pop on me once. One of the first orifices on the bar had been plugged by small spider web and the flame had not moved from the pilot to the first burner and so on down the line. The pooled propane at my feet got it spark and I got a good flash and whoosh. My boss paid for a fresh haircut and sent me to school for heater repair. i did have on safety glasses and avoided that injury. I did like the plans and you have given me an idea on something I have beeen thinking about. The trick is going to make a round burner for my project. keep up the experimenting. Thanks
How to Make a BBQ Burner: Page 11 Never happened to think of using slots instead of holes, but I do like the flame produced. Thanks for the idea!
For longevity of the tube I would think holes better than the slits. The tubes burn out at the orifice and the more material there, the longer they will last. I have a drill press and that and a v-block make the hole drill easy. For me, this started with my gas stove which ceased being manufactured about a year after I bought it, about 25 years ago. About 8 years into this, the S-shaped burner tubes had just given up. No replacements available. I took the burner out to the shop and realized the tube was nearly identical in diameter to some scraps of steel conduit I had laying around. The tube only seems to burn in the straight runs, the loop ends are just fine, maybe because the heat is concentrated in the straight sections. I cut the bad sections out, drill holes down the conduit matching the original hole diameter and spacing and welded the two together. Lasted for about 8 years and had to repeat the process. I have repaired gas BBQ's the same way and honestly haven't seen much difference in the life span of stainless vs. the conduit of a similar wall thickness. I don't think it's corrosion the causes the burnout of the tubes. Probably depends on the grade of metal. I figure the galvanizing burns off about as much as it's going to in the first hour or so of burning. Not something I lose sleep over. The savings over the years of keeping these things alive and working fine has been huge and satisfying.
AAMOF, doing a quick google search it looks like most cheaper grill and oven burners are galvanized and you know that stuff is thinner than even galvanized conduit .
Yea, you have me wondering about that... conduit would make this cheap and REALLY easy to make and almost as durable. I'm pretty sure that I have seen galvanized burners before (I know they weren't stainless and they had some sort of coating keeping them from rusting out right away). Galvanizing burns off at electric welding temps (MIG, TIG, stick), but I doubt a propane flame will do it (likely 1/3-1/4 the temp at the hottest point which is away from the burner).
Taking that a step further galvanized iron pipe would would likely last longer then thin wall stainless if you're OK with the galvanizing.
It is "oxidizing" (rusting) but it is accelerated by heat and oxygen in its vicinity. I suspect that if you run it a little rich (some extra yellow flame) they would last longer but I wonder if the mercaptans mixed with the propane would mess with the flavor (you can bathe your food in raw propane and it won't hurt you). side note, and unlikely to be a real problem but worth stating anyway. Do not use galvanized steel parts in your burner. This can, over time and with heat, result in health issues. (extened version: galvanized metal has a layer of Zinc on it. At high heat, or when cutting/sanding/abrading it you can release Zinc into the air. A small amount won't do much harm, but a lot with repeated exposure cna make you ill. Extended repeated exposures can have permanent effects on your health.)
How to Make a BBQ Burner: Page 12 Yup black iron fittings only, or soak in vinegar to remove the galivanization.
I'd be pretty shocked if vinegar removed it in any reasonable period of time. Typically you need to resort to mechanical grinding or muriatic acid.
Nice job. Question: Can this burner be done the same way except with flattening the end of the tube and not welding it? I realize that this end needs to be air/gas tight so would a little exhaust pipe glue or tape along with the flattening work?
It would work but almost any kind of reasonable stainless will be pretty hard to get flat enough to seal. "Exhaust pipe glue" wouldn't last long (typically a very stiff ceraminc compound that would just crack out of the joint after a few heat cycles) and is fairly toxic.
You could flatten and fold the end & it should work just fine.
Hmm while what you suggest would work for the short term not sure how it would work for the long term. If you don't have a welder you could try brazing it with torch.
How many BTU's/hr does it run at assuming the rate shown in the beginning of the video?
Inspiring build. Great video too.
I've been want to convert my Weber to gas for a long time but didn't really know where to start. Now I have no excuse...
Any reason not to use copper pipe? Thing is, where I live, getting hold of a short bit of stainless is not going to be easy but 22mm copper I have plenty left over from plumbing jobs and brazing that will be a piece of cake.
Copper would work and I have tried it on other projects, issue is the longevity of the burner, copper would not last. But on the plus copper is so much easier to work with. is there a reason for cutting lines and not drilling a hole?
What rednecknerd said and stainless steel work hardens like crazy, not a fun material to drill.
He actually explains the reason for this in the instructable. It was to save time and work during construction. Drilling holes takes longer. Using a bandsaw or hacksaw to cut slits is faster.
How to Make a BBQ Burner: Page 13 Ok thanks:-) I just saw the pictures. did not had the time to read. Will do it soon.
Nice burner will try this on the next beer barrel spit I make. In you finished burner did you drill holes in the side of the 2" to 1" reducer or did it draw enough air though the end.
It draws enough from the end, drilling the holes made no difference.
Good job I plan to replace my burner tube! What grade of stainless steel did you use?
304 is what they stocked but the type is less important than the wall thickness, thicker walls = longer life.
Finally! Will be building this shortly... How deep did you cut the slots in the tubing?
Honestly I just guessed about 1/4 to 1/3 of the way.
How to Make a BBQ Burner: Page 14