Propane fire pit from copper fittings and a flower pot

Fire. Man's best friend, scourge of vampires, zombies, and other things that go bump in the night. Mastery of fire is what separates mankind from the animals. That and it is fun to watch.

This instructable presents my method of building a propane powered fire pit inspired by another fine instructable: http://www.instructables.com/id/Sand-Fire-Garden/

My method makes use of readily available copper tubing and fittings and requires soldering rather than welding. Also, my vessel is a simple ceramic flower pot rather than a stainless steel wok.

Before we get started, be aware that the construction and use of this fire pit involves fire, which when in the wrong hands can be extremely hazardous to life, limb, and property. Please observe all applicable safety precautions and local ordinances when building and using this device. Follow these instructions at your own risk.

Step 1: Bill of materials

Bill of Materials:
(1x) 10' roll of 1/2" bendable copper tubing
(1x) 10' roll of 1/4" bendable copper tubing
(1x) 5' section of 3/4" rigid copper tubing
(3x) 3/4" copper pipe caps
(3x) 1/2" to 3/4" copper T's
(3x) 1/2" copper T's
(1x) 1/2" copper to 1/2" FPT adapter
(1x) 1/2" MPT pipe nipple 1.5" long
(1x) 1/2" FPT 90 pipe elbow
(1x) 1/2" MPT to 3/8" flare adapter
(2x) Large stainless fender washers
(2x) Large silicone O-rings (with greater than 3/4" inner diameter)
(1x) Adjustable high pressure propane regulator
(1x) 10' long high pressure propane hose
(1x) Ceramic flower pot
Play sand or similar to fill your flower pot

Tools and Equipment:
Lead free solder
Lead free soldering flux
Propane torch or equivalent
Wire brushes or emery paper for cleaning copper
Tubing cutter or hacksaw
Teflon tape for pipe fittings
Power drill and 1/16" bit for drilling holes in burner
Spring tubing bender or similar
Soapy water and spray bottle for leak checking
Steady hands and an iron will

Comments

[kchapman8]

My progress
First pic is the fire pit as it was
Second, I cut out the support in the middle for leeway for my stainless steel "fire bowl"
Third, I took the "ashtrays" out to use them as a "riser" for the bowl
Finally, cut a circle into them for my bowl.

Next week, ordering my fire pit kit, getting propane tank, media, and we'll be on our way

[kchapman8]

How has this been holding up? I'd like to take this idea and apply it to my wood burning fire pit

[jmengel]

Holding up well, although the sand has blackened somewhat. For a wood fired pit, I'd be sure and keep the heat low on the soldered joints. You sure wouldn't want the whole thing to fall apart with a hot fire in it.

[kchapman8]

Maybe I misspoke, or in misunderstanding you, so let me further explain.

I'm going to use a store bought fire pit, made from metal, do a little fabrication, and end up with a full size propane fire pit.

[kchapman8]

So no wood will be burning in this fire pit when I'm finished is what I'm getting at. Why I can't be more to the point, I dunno :-)

[jmengel]

Sounds like a good plan. Let us know how it goes. I've been thinking about the blackening of the sand in my pit. I think the propane is pooling in the sand and pot, and the burning is happening at the interface of this pool of heavy propane and the air which is leading to incomplete or sooty combustion. Not sure how to fix it. Might be that a less porous (finer) layer of sand would cut back on the burning happening in the top sand layer (rich) and thus the soot. Not sure.

[kchapman8]

Isn't there supposed to be a special orifice that injects air into the propane mix to avoid that very thing from happening? I know, in researching this, I've seen that recommendation numerous times. Propane burns "dirty", while natural gas burns clean. Just a thought

[jmengel]

Yes, there are air mixer fittings that are basically a brass coupler with holes to allow air to be entrained into the gas flow. Been hesitant to use one. Not sure what type of safety features are needed to prevent backfiring out of these air hole. Ideas?

[kchapman8]

My idea..... I decided to buy a fire pit kit from the instructable you linked to above. He sells everything needed, minus tank and fire media, for a decent price.

[mr. clean]

To anneal the copper and make it much easier to bend heat as much length as desired to a dull red glow then allow to air cool or dip it in water and it will have become very soft, however the only way to harden it again is to work the copper.

[jmengel]

The coil of 1/2" copper tube comes pre-annealed. Making tight bends as required by the burner portion quickly work hardens it. You could re-anneal the tube pieces as you work, but sounds like too much effort to me.

[mr. clean]

Idk tough to say it might be the same amount effort either way because if you take the time to re-anneal then its easier to bend but with out re-annealing it then you have to muscle it more so I suppose it's just personal preference.

[rimar2000]

This is very interesting. Thanks for sharing.