Propane burner build: The Mule

First build thread, first burner build.

Back in the 70's I saw some backyard metal casting work done by my sister's neighbor, never saw the complete set up but was totally impressed... E36 M3, gotta do that someday. About ten years ago I began researching internet sites and YouTube, other projects took precedence tho. The recent foundry threads reminded me that it's 'someday' now and a burner build would be a perfect winter project.

Spent many hours researching and taking notes of where I wanted to go w/ this build. Every builder has their own style and application whether forge or furnace work. Nothing all too much original on my part but taking what I thought the better ideas from each build. I wanted to add quick change adjustments as well to experiment for different applications, so it's called the Mule.

Why do all that?... I'll preface the build w/ because I have plenty of time on my hands, doesn't require jackstands in winter, fits in a 8X12 cardboard box to carry anywhere and doesn't cost like car projects.

Also, who don't like playin' w/ fire... kinda like a big kid science project.

On to the build:

Ordered parts online rather than chasing around locally. Online build consensus was 7-8" Schedule 40 black nipple w/ 1-1/4" to 1-1/2" max BMI reduced coupling for the air inlet side. 1" x 3/4" reducer for the flame side, ordered that in SS.

Chose a 2" x 3/4" reducer to add a primary air shutter for adjustment, may be room for a diffuser also, we'll see.

Import casting is OK for regular piping duty, rather irregular though as I'll soon find out. Domestic may not be that better btw.

Ground the threads out w/ a carbide burr and tried to smooth the lumps and casting lines. Inside is more oval than round. Porting kit cartridge rolls didn't do much to smooth. Surfaced the fitting faces on a pedestal disc sander.

Not bad but had one more idear... ya know, while you're in there.

Paint stripper wheel oughta help smooth that out. Stumbled across the HF kit for $7.49. Chucked it up in the drill and ground the diameter down and radiused the edges on the bench grinder to fit inside the bell. Wow, made short work of it.

Gotta, gotta recommend this for small metal finishing:

http://www.harborfreight.com/2-in-conditioningstripping-kit-69777.html

Result:

Ground the ridges outta the nipple ends from cutting and threading w/ a burr and smoothed the ID w/ tool made from old mower strut? Shown above, Sawzall cut, heavy emery paper in the drill polished out any scale like a hone.

Import nipples like found at HD have a pronounced weld seam ridge inside the pipe. Domestic, I found not so much if any.

Following along, how much of a difference does polishing/removing the threads really make?

In reply to java230:

I have absolutely no berkeleying idea. Like I said, gotta lotta time on my hands to get 'er done.

This ain't the Easy Button but my preferences. You could basically build a functioning burner in one afternoon and have at it.

Centering tool made from a long 3/8" bolt, hex head removed and w/ two 5/16" washers w/ 3/8" ID. Soaked in muriatic acid to remove cad plating before welding. Shaft chucked in drill and spun against bench grinder till washers slip fit inside pipe ID.

Result:

Start of carrier for nozzle assembly. 3/4" x 1" stock from the shelf. 3/8" drill thru, squared and radiused on pedestal disc sander. Drill and tap 1/4-20 NC for bolt as a handle during forming, later to be used for set screw for nozzle pipe assembly. Used 3/8" OD tubing bent 90° for pivot during radiusing against disc sander to save my fingers.

Missing pics in this segment.

Finished carrier block w/ 3/16" x 3/4" flat stock welded on center. Corners radiused w/ burr, contoured w/ porting cartridge roll. My Dykem went MIA so wide tip black Mark-X for layout and scribed.

Went heavy cause lotta stuff will be hangin' off that block.

Woulda been a helluva lot easier and a much better finish to just mill that piece out but my Bridgeport ain't converted yet and the daylight only machinist in our building locks everything up... so no playtime for me on midnight.

Interesting. Subscribed.

I like this.

Transferred scribe marks down each side. Pilot drill then 3/16" drill at bottom of slot. Cutoff wheel to complete the slots.

Allowed a little block stick up above face to be surfaced later. Trim ends, MIG weld sides and face.

Missed pictures during that segment. Bell face and OD have been surfaced on the pedestal disc sander.

Made a radius scribe tool from flat aluminum stock and a TIG tungsten. Mark-X Dykem FTW.

Laid out 6 hole pattern on a paper template and transferred to the bell face. Slight compensation for two holes because casting being irregular, it's not as round as it looks. Drill and tap 10-24 NC.

It's starting to look like somethin'

I don't think I'm going to fully understand what you're doing until you're done, but I'm very interested in it.

In reply to mazdeuce:

I think we're looking at the construction of the air inlet area of a bigass propane blowtorch

So the bottom partof a bunson burner? Leave an adjustable air gap to suck in oxygen? That sort of thing?

Propane burner for a foundry

Nice looking! Mine doesn't meet NASA standards like yours will but same basic idea. I just through it together, eyeballed the center and drilled a #59 hole in the side of a piece of 1/8" pipe to bridge the bell. I've used the same burner to feed my 4'x4'x8' powder coating oven and my melting furnace. Quick calculations say its making about 280K Btu.

The diffuser end will be way more important. You'll need to slow the flame down to keep it attached to the burner. I took a 3" long hunk of stainless pipe that slid over the black pipe and heated and hammered it to flare one end. It didn't take much flare, maybe a 1/4" increase in dia over 2"

java230 wrote: Propane burner for a foundry

I know what it's for, just not how the particular beautifully fabricated piece actually works. Yet.

The sleeve in the center with the set screw is a guide for the propane jet.

Gas draws air with it through the bell, into a short length of pipe then the mixed gas is burned on the opposite end.

Same basic tech used on BBQ's and stoves.

Polishing the inside of the bell doesn't make for much of a difference, but looks nice!

Start of primary air shutter:

I had flat stock and auto body metal on the shelf but came across these box covers at HD for 60¢ each. Nice and flat and had slots for hold downs already. Screw onto flat board and hole saw cut.

Used same radius scribe and paper template to layout shutter base plate. Cutout OD was larger than bell diameter so ground it flush on the disc sander.

Drilled the corners of opening first for radius, cutoff wheel next and carbide burr to rough in, file to finish. Lotta file work on midnight shift. Being rather conservative w/ the opening, could always remove more out of the center later if needed.

Shutter wheel next. Another hole saw cutout w/ OD ground to fit.

Pared down w/ drill for radius, cutoff wheel and filed to finish.

Full open as shown.

In reply to fasted58:

Is this "Government" work? If so, glad to see it's a universal millwright thing...