Open air burners vs gas forge burners

[Glenn]

There has been a good discussion on the site about gas forge burners, getting them to work properly etc.

But what about open air burners, those used just for heat and without an enclosure?  Think of a burner attached to a wall and standing out a bit where you can put sheet metal under it to heat it up for bending, hammering, etc. think making armour.  Or maybe a hand held version to keep heat on pieces of iron that are being bent, or large scrolls. An open burner could be mobile and used to heat the bolts to help loosen them on machinery.

What are the requirements of an open air burner, and how are they constructed so they work well?

 

[Irondragon Forge ClayWorks]

I would think a small ribbon burner would work best. It would need finite fuel & air controls like needle valve & air choke.

[Mikey98118]

Some requirements change and others don't. since heat dissipation is the central problem, a coal forge would seem to be one answer. Rapid heating with oxy-fuel torches is another way to go for shop work on odd jobs. Even partial containment of exhaust gases greatly reduce fuel use, so cast refractory or refractory brick tables and partial walls (backboards) to retain some flame heat are called for. If the job is big enough to justify the expense, ceramic wool blanket can be use as a backing board, and discarded afterward.   

[Mikey98118]

Also, switching to a hotter fuel (like propylene) could make a large enough air-fuel burner a practical alternative to oxy-fuel torches. Hotter fuels combined with better air-fuel burners good for silver brazing of large objects. The English have used chip forges to heat work from below while air-fuel burners provide extra heat to bring up small target areas at a time on large work pieces.

[Frosty]

I think you're getting carried away here Mike. Using a NA gas burner like a hand torch and expecting to get forging heat wouldn't be very realistic. It'd be easier to make a temporary specialty forge. Maybe what you're describing.

What I envision a person using a NA burner as a torch for would be as a soft flame on a large area, say torch  enameling copper or maybe heat patination on a sculpture, gate, etc. How about raku glaze applications? How about hand sinking a 24" wok from 14 ga.?

There are lots of applications for a hand held or clamp on air propane torch that doesn't cost a few hundred bucks.

Frosty The Lucky.