Turner plumbers melting furnace rebuild

[geddylee10002000]

I have a classic Turner Brass Works plumber's melting furnace. Not a blow torch. It is LP fired (not regulated). I have had it for 25+ years. Recently while casting I knocked a sprue off and it ended up melted around and on the orifice and plugged it. I am a master tool/die maker. I measured the orifice on the backside and drilled the orifice completely out at a #47 (.0785) getting all the lead out of the brass orifice. Now my furnace burns with a large, mostly yellow, sooty flame. Messed up. Need to get back to the original specs as I am happy with them.

My burner is a Turner that is stamped Turner LPH with a "M" and a number "3". The brass orifice is not coded at all.

What size orifice do I need? I would buy a regulator if needed. I have done a bit of surfing and have visited the local vendor. I have called some of the current plumbers melting furnace vendors and their specs for orifice size is 1/8 in. Wow.... Not even close. The best guess on my part after research is a #58 drill (.042).

I have charts to point me to the orifice size and BTU output regulated and unregulated. Anything from 30,000 to 80,000 BTU output. Ray Murray furnaces at about 73,000 BTU is what I am shooting for. Something to take 20 - 40 lbs of lead to melt in about 5 minutes.

I am not trying to invent the wheel again. Don't have a ton of time to invest either. Just want to smelt and cast boolits.

[Mal Paso]

Is the Air Horn that the orifice blows into blocked in any way? Sounds like not enough air. You may have the orifice right. Unless it's been peaned and redrilled the orifice should be the same front and back. A spider web in the Air Horn is enough to disrupt the gas jets ability to pull in fresh air by venturi action.

[W.R.Buchanan]

Why don't you make a new orifice, and start at about .030 dia, and then open it up until it burns right?

If you have a number drill set it shouldn't be too hard to find the correct size just by going up one or two drill sizes per attempt.

Unless someone has one of these burners and can accurately measure the hole, it will always be a guess or just plain BS. Finding the real right size will still be trial and error...

You might as well just do it right the first time.

Randy

[John Guedry]

It sounds like not enough air to me too. For what thats worth.

[geddylee10002000]

Thanks for all the input. What I have did so far is to completely take the burner apart, bead blast it, and paint it. I have made 2 orifices to try. #60 (.040) and a #65 (.035). I have bought a high pressure regulator. Haven't had time to reassemble the burner and try it. Should be interesting