Introduction: Design and Construction of a Kerosene Fueled "Gasification" Grill
The 1st question is why? Why not! You can cook with kerosene, bake with it, broil with it, Cool your food, freeze your food, heat your water and even light your home. So why not grill with it?
2nd question is why? Because I thought it could be done and done better than a small gas grill. Every gas grill I have cooked on has hot and cold spots. You have to move food around to get a grate full of food cooked at the same time. 3rd question is still why? Ever empty a conventional gas grill in the middle of a cook? Got a spare tank? Most don't. No problem, just run to the store and swap out tanks. Oops! It's a holiday and everything is closed. With this "Perfection Gasification" grill, just refill the gallon glass jug!
Isn't Propane better for a "Gas" Grill? Define better? It lights quicker. It burns a bit cleaner but produces more water vapor and CO. And it can explode if released into the air.
A Kerosene "Gasification" grill is a bit harder to light, burns a bit dirtier, and absolutely will not explode if released into the atmosphere! For over a hundred years Kerosene has been successfully used in stoves and ranges. So my crazy idea was to use multiple stove burners in a conventional gas grill body. I also hope to reduce or eliminate the hot and cold spots prevalent with conventional gas grills. So, I will put my extensive experience with Kerosene cook stoves to use and build a grill that outperforms a gas grill of similar size. Quite a tall order I know. From the above images, Stove + Grill = Kerosene Gasification Grill!
Step 1: The "Donor Grill"
Since I will not re-invent the wheel, I will not attempt to design my own gas grill body. Most 2 - 3 burner gas grills are built to a price, not a quality. Therefor most burners rust out in 2 - 3 yrs. And most of these grills end up at the local recycling / transfer station. Very few are ever rebuilt with either new factory burners or aftermarket stainless steel burners.
So it didn't take much searching to find a 2 yr old Uniflame GBC 1103W, 2 burner with 27,000 Btu output with rusted out burners and a very good chassis at the recycling center.
Strip it down to its bare chassis and start the rebuild.
Step 2: The Mock Ups
Ya gotta start somewhere and for a Kerosene grill it is with the fuel reservoir holder and fuel transfer pipe.
Remove the rotted burner, and the tub. Cut out the bottom of the tub to allow the chimneys dump heat into the tub.
I will cheat and use the exact spacing between the top of chimney and the cooking grate on a Perfection cook stove and transfer that dimension to the grill only now measure from the top of the chimney to the bottom of the heat diffuser.
The height from the top of the chimney to the heat deflector should be the same as a Perfection stove's chimney top to the cooking grate ( 2 in.). No sense re-inventing the wheel here. The spacing has been tested since 1906 and it just works! Shoehorn in three burners for 24,000 Btu's and we'll will see if it actually works!
I acquired three used Perfection stove burners and chimneys from Ebay.
The kerosene feed tube is 3/8" black iron pipe.
Spacing with burners clamped in place revealed a minimum distance of 6-3/8", feed port to feed port, is optimal for .providing just enough clearance for the chimneys. The goal here is to keep the burners as close together as possible for even heating down the middle of the cook surface and utilize a custom made stainless steel heat diffuser to distribute the heat to the rest of the cooking surface.
Step 3: Thread Problems
The Perfection factory used a straight, un-tapered, thread to attach their feed pipe to the well. But the stove spacing for the burners of a factory feed pipe is way too far apart for even heat. So you have to "roll yer own". This un-tapered thread is very hard to come by in black iron. I used a Brass nipple, which is most always un-tapered to thread into the kerosene well.
Use plenty of Teflon tape to tighten the threads up. Make sure your Teflon tape is rated for petrochemicals. Next is a 45 deg elbow. These two pieces matches the factory bent feed pipe.
Step 4: More Thread Problems
The Perfection Stove Company used an aluminum orifice to get kerosene into the burner. Original and current production, Schwartz stoves use an obsolete thread of 1/4-32, that is very difficult to obtain a tap locally except for the Schwartz factory. I chose a 1/4" Allen, because it fits the modern plastic seal (The vintage seals were soft lead.) and is a modern 1/4-28 thread, so it is easy to obtain a tap. A lathe can drill the bolt lengthwise to match the factory hole size, 0.135" and while it is in the lathe, whittle down the Allen head to original factory dimensions of 0.303" to fit the burner's feed hole of 0.307".
Step 5: Installing the Burners on the Feed Pipe
Each Burner is placed on the Feed Pipe with the bent hook under the Feed Pipe. Then a clamp is placed over the feed port and tightened down, producing a leak free seal as the burner is pushed onto the nylon seal. The orifice is now up inside the burner, ready to deliver kerosene to the wick.
Step 6: Test Fitting the Chimneys
The 3 piece original Perfection Stove Company chimneys have rings top and bottom, that with the 6-3/8" feed orifice spacing, hit each other. Current production Schwartz 1 piece spun chimneys would work better here.
Next the glass fuel jug was placed in the kerosene well and the burners were leak tested. If done right there should be no leaks. And there wasn't! Might actually know what I'm doing!
Step 7: Test Fire
The tub was set in place and the fit was checked when the chimneys were tilted backwards for lighting. More clearance was needed. Cut and re-check again. Then the three burners were lit.
Step 8: Test Cook
I dropped the stainless steel heat diffuser into place and the cooking grate and tossed on a steak and some boneless pork chops.
The heat seemed quite even with no noticeable hot or cold spots. Apparently the heavy stainless steel heat diffuser I had made from the thin tin original was working.
I also noted that as the burners heated up and the brass expanded, the burners leaked! Apparently that was why the burners were originally removed from a vintage stove and sold individually on Ebay!!
Step 9: Time to Get Scientific and Check the Heat Dispersal of the Grill
According to the infrared images, the heat is well distributed from edge to edge. There does seem to be a cold spot directly above the center burner?? It reads 50 deg. F cooler than the surrounding area. However actually cooking on it, I didn't notice that "cold" spot at all??!
Step 10: Replace Those Used Ebay Parts With Brand New Current Production Schwartz Parts
I took a trip to Berne, Ind. to the Schwartz Mfg. plant where they are still making pre-war Perfection stoves and ranges.
Here is a tour of the Schwartz Factory.
Here is the video of the 331X stove wicks being produced on the original pre-war machinery.
I picked up three new burners w/wicks, and three new style 1 piece spun chimneys.
Step 11: Install the New Schwartz Burners!
All shiny and new. And they won't leak!
Step 12: Install the New Schwartz 1 Piece Spun Chimneys!
With the 1 piece spun chimneys in place, I now have the correct spacing between the chimneys.
Step 13: Another Test Burn
This burn showed the limitations of using indoor burners. They really didn't like any breeze at all. So the fix was to wrap the grill's frame with aluminum flashing and then paint it black to match the frame. This created a dead air space to act as a baffle for breezes.
Step 14: The Completed Grill
The grill is now complete and after a chicken cook I had to place a sheet pan to catch grease that was atomized and condensed on the top cover and then dripping down to the bottom of the tub and onto the ground.
Step 15: All That Is Left Is to Actually Use It!
And use it we did and do. 3 X 8000 btu burners = 24,000 btu's, so it is a little less than the propane versions 27,000 btu, but because it has such even heat, it seems to cook really fast.
Step 16: It Is Very Economical
It uses very little Kerosene. (each gallon of Kerosene has 138,000 btu's vs 93,000 for a gallon of Propane) Note the fuel jug, it was full before we started cooking and we cooked all that food for about a dollars worth of Kerosene (current price for clear Kerosene locally is $3.39/gal.)
And NO, NOTHING TASTES LIKE KEROSENE! As if there is something wrong with that! :)
Here is the official TEP video of the Gasification Grill.
Now I don't expect anybody but TEP to actually build another Kerosene Gasification Grill, but it can be done and since it cooks superior to other small propane gas grills, it is requested for our family cookouts over the propane version that we still have (but don't use anymore).