This thread is to assist others in understanding the How’s, Why’s and Results of properly and improperly building and aligning all components of such a build in addition to the proper placement of the burner within the forge burner holder.
In no way or form is this thread intended to replace IFI’s Forge 101, Burners 101 or any other threads and the information within those threads which has been made a sticky and it is HIGHLY ADVISED to read any & all of those threads in their entirety for your specific build.
This thread, in a nut shell, is basically what I have comprehended from both those threads and other credible information gathered and applied over the last year.
I am continuously learning new aspects and facts of the World of Fire each and every day.
In no way or manner shall I be held liable for personal physical injury or property damages resulting from anybody copying in part or whole the build and design of the this burner. If copied in part or whole the builder/user does so SOLEY at their own risk.
This is not a One Size Fits All.
No 2 burners perform identically.
This is just to give a general overview and understanding of what to look for.
Basic shop tools were utilized for this build.
Dremel, abrasive cutoff wheels, drum sanding barrels, drill press with a properly aligned table to spindle/chuck head, stationary vise, drill bits, taps, TIG welder (optional),
angle grinder w/ cutoff disk or a cold cut chop saw, wrenches.
NA Mickey Burner
The burner’s specs are as follows:
Burner Tube: 304L Stainless Steel, schedule 40
There’s 5 air intake ports which are 1/2” x 3” for a total of 7-1/2 square inches of intake.
The mixing tube is on the short side of 7-1/8” excluding the nozzle but it works.
As Mikey recommends in Burners101 the “mixing tube” side should be around 8”- 9” in length.
For clarification, this would be the part of the burner tube beyond the intake ports.
Once I figured out what size of intake openings I needed, I taped the pipe off accordingly, sprayed it w/ rattle can paint, removed the necessary masking and proceeded to make my cuts with a dremel and cutoff disks while it was secured within my table vise.
Once all cuts were made I took a screw driver and gently pried one end up where I could grasp the cut out with needle nose pliers to finish removing.
Do Not pry the cut out sections up by resting the screw drive anywhere but at the ends of the intake ribs to prevent from damaging them.
The Fuel jet (Mig tip) is a hit or miss thing and will need to be played with to achieve optimal performance with your particular burner.
This particular burner started out with a .045 mig tip for the jet but that was too rich.
For some reason I’m thinking the id of a .045 tip is .0625.
Tried pulling it up on the net but can’t verify that number.
It was replaced with a .035 tip which I drilled out with a #55 (.0520) drill bit.
If you do drill these tips out it works best using a drill press and lubricant. I like using a bar of soap to lube the bit. Take your time, bore a little, back out clearing the chamber, repeat, repeat, repeat.
That size jet seems to work great for this particular burner, forge construction and my geographical location due to atmospheric pressures, etc.
The Mig tip jet is secured with standard ¼” brass plumbing fittings.
HIGHLY advised to spray all connections with soapy water PRIOR to striking a flame to the burner to detect any fuel leakage within your configurational setup.
As also suggested, a Tapered MIG welding contact tip works best for the burner jet.
Another thing to be on the lookout for it where the jet tip is positioned within the burner throat (at the beginning of the air intakes) this also will play a role in how the burner functions.
The end of the jet tip should be protruding approximately 3/8” past the back of the intakes for a starting point of fine tuning your burner and it’s operation.
Intake Air Ports
The fore and aft ends of the intake ports have been beveled as recommended in Burners 101 for a smoother transitional flow intake of air within the mixing tube which reduces/eliminates turbulence for smoother operation.
The beginning of the intake chamber closest to your jet needs to be beveled on the “outside” tapering into the intake port.
The end of the intake chamber farthest from the jet side needs to be beveled on the “inside” creating a funnel.
The ribs between the individual intake ports are ¼” wide and have been beveled/tapered as well to reduce turbulence.
Anything you can do to eliminate or reduce turbulence is a plus in the design and operation of the burner.
Coupler & End Cap
Coupler: Holes were drilled and nuts were welded in place. This was the easiest route as SS isn’t the funniest stuff to fabricated compared to mild steel.
This procedure can be accomplished by using standard plumbing fittings with drilled and tapped set screw holes.
The end cap plug is a standard steel plumbing fitting.
Holes drilled, tapped and set screws installed.
By fabricating it in this fashion it allows the builder/user to connect a piece of hose and a spigot fitting to the water hose and the fuel rail/pipe nipple which connects to the mig tip/jet setup for proper fuel stream alignment down the center of the mixing tube.
Originally I attached a SS concentric reducer (1-1/4” to 1-1/2”) which in reality resulted in a 1” id mixing tube diameter to the widest end of the flare which as stated was 1-1/2”.
Running @ 8psi the results of such....
If I remember correctly, it is stated that the flame side of the nozzle needs to have a taper of 1 to 12% gradual taper outward.
That will need to be verified by the builder within Burners 101.
I replaced the above mentioned nozzle with a piece of 316 SS 1-1/4”id straight pipe 2-1/4"L w/ a 2" inner working chamber one attached.
It needed to be beveled out on the flame side ever so slightly to stabilize and hold a flame within the forge, I'm going to bevel it out even more when I get around to it.
Aligning Burner Jet Stream
Unless the burner components were fabricated using a lathe and mill (precisely) the jet stream Will Not be dead centered.
Improper jet alignment is a bad thing.
Below is the result of a hand fabricated burner with the jet housing just screwed onto the burner mixing tube.
Secure the burner in a vise, remove the burner nozzle, connect the jet alignment hose setup with a hose clamp to the fuel jet nipple fitting, turn water on and adjust the jet stream via the set screws until dead center.
By removing the nozzle, this will allow the tuner to get the jet stream dead center of the mixing tube.
Once the Burner has been aligned the nozzle can be reattached and centered per the jet stream.
Methodically and gently tighten the set screws snuggly but not so tight to disturb the alignment and your good to go.
As mentioned in Burners 101 this aspect is critical in the proper function of any NA burner.
Testing Outside the Forge
This particular burner will not hold a flame outside the forge yet has no problem firing up and holding a stabilized flame within the forge.
Why is this?
Outside the forge it lacks back pressure to hold a stabilized flame in the nozzle.
I also suspect this issue is due to the lack of taper travel into the nozzle.
So, just because it won’t hold a flame outside the forge doesn’t necessarily mean it won’t work inside the forge.
Test & Tune accordingly.
Burner Holder & Burner Placement Within
2” id schedule 40 mild steel pipe was used for the holders which serves multiple functions.
I designed my forge to accommodate and utilize a single burner or multiple burners depending on the job.
Secondly, such a design also allows different sized burners to be used in the arranged holder ports.
Thirdly, It allows the operator to fine tune the air intake or restriction of air flow into the chamber wherefore regulating such and the ability to create a reducing, neutral or oxidizing atmospheric state.
Fourthly, It allows adjustment of the burner flame direction placement.
Lastly, any of the un-operational Burner holder ports can be used as a chimney.
When using a hard castable refractory as an inner shell the section of the holders which will be passing through the shell should have a few slots cut into them for expansion purposes to prevent cracking of the inner hard shell.
I chose to wallow out the passages of the hard refractory where the burner port holders went for final adjustment of the holder position prior to welding them in place.
This also created an expansion allowance for the holders to expand and not crack the inner shell.
The burner holder’s inner port opening closest to the inner chamber should be slightly beveled to eliminate any burrs or lips which will create turbulence or disrupt a properly tuned flame entering the forge's chamber.
It is also advised the burner holder(s) need to be positioned as to not allow the holders end(s) to enter the forge’s chamber walls to prevent melt down.
The burner nozzle(s) should be placed within the burner holders approximately 1/4" 1/2” pulled back from the end of the holders to further prevent nozzle melt downs.
Hence, the reason for beveling and removing any obstruction(s) (burrs or lips) from inside of the burner holder on the flame end.
Again, anything and everything which results in a smoother transitional air flow or flame path should be done to achieve maximum performance.
I haven’t done the deburring of my inner burner ports as of this posting and as a result it can be seen within the flames contoured shape.
Running @ 8psi.