Pipe burners. simple, effective, and so many pipe parts to chose from.. A few brass water plumping parts, all off the shelf from HD.. A drill and metal cutting disk on my 4.5" grinder are all the tools needed.. Only need to drill 4 holes, and 4 cuts with the grinder.. I admit I haven't used the larger burner sizes.. They might need the orifice drilled larger and tuned to burner length.. The orifice used is from a wire feed welder.. They come in different sizes, but may be need to be drilled larger for bigger pipe burner.. The last pic is the one used on my furnace.. A 1/4" compression connector holds the orifice..
So glad to see I'm not the only Mixer-Matcher. I was going to the hardware store almost daily with any spare change I had buying elbows, reducers, just any couplers and fittings I could get. Do we get to see it all lined up and then all together? Looks like you're doing naturally aspirated but hard to tell.
This is the oven I used one of the small burner sizes in.. Small aluminum propane furnace.. | The Home Foundry