We were lucky enough to pick up a vintage Malm Zircon-38 fireplace last summer from a house that was doing some demo — that the piece only cost $75 (instead of 10X–20X that price) was the first shocker. Next, the ease of transitioning it to a gas (propane) fired fire-pit was the second one. All in, I think we're at about $500 tops.
When we picked it up (thanks to my friend Bret for the lifting help), we knew it was going to take some TLC. It had been in a mid-century living room for years and was unloved a good bit of that time. Some of the bits were bent and some of the porcelain had chipped off (come to find out, this will be a recurring problem). But, as they say: "it has good bones" and was a perfect candidate for an outside fire-pit/fireplace, so I got to work... It wasn't until the following year, however, that the conversion to a propane fuel source made sense (after the latest CA wildfire, I doubt we'll even light another wood-burning fire. With a pending s'mores-fueled birthday/pool party, it was time to start the project.
Disassembly // First, came the disassembly. All of the requisite pieces came apart easily. A few sheet metal screws and bolts were holding the five pieces (base, pan, shell, fire-stop and exhaust) together. It would be easier with two people, it but it's possible with one.
Plumbing // Then came the daunting part — drilling for the burner. After measuring out all of the pieces, a 3/4in hole was drilled in the original base for the propane burner — this was the only real modification as the base already drained (water) from the two corners and I saw no real need to put any more holes in the otherwise original base.
All of the burner pieces were procured from Amazon. There are dozens of kits and bits out there, but I opted for the Stanbroil "Jet" version in an 18in circle. Our fireplace is the largest made at 38in, so most others might opt for the 12in ring. As-is, the 18in is a tiny bit big, but 12in would be too small in this version.
Restoration // Next came the stripping and re-painting. The shell and exhaust pipes are porcelain enamel coated and are fairly impervious. The base, pan, and fire-stop, however, were raw steel with just a light oxide coating and needed some rust-repair. Fortunately, quick work with the grinding wheel found the pieces cleaned up and they were coated with Rust-Reformer and "Industrial" flat-black paint to retain the original look and be easily repaired. I'd have preferred to use POR-15 in the base of the pan, but a few heavy coats of gloss-black brake-caliper enamel that I had on hand gives it a fairly solid coating for durability (on the interior of the base only — where water might collect). The fire stop was coated with BBQ high-heat enamel.
Once the burner ring was assembled with the requisite bends and adapters, it was time to give it a test and it worked beautifully.
Finishing // Next came replacing the refractory cement. We could have likely opted for a simple decomposed granite or sand fill, but giving it a solid base was important for outside use (read: windy). The DIY refractory is made from 1/2 mortar mix and 1/2 perlite. I'd have opted for a 1/2 mortar, 1/4 perlite (crushed styrofoam), 1/4 vermiculite (crushed coral), but vermiculite was not to be found locally. Additionally, the burner keeps all heat above the cement, so it simply needed to be solid. I used a block of plywood to keep the cement away from the burner plumbing location. When the cement was set (about 6 hours later), I removed the block, reconnected the burner and topped it all with decomposed granite. Then came the lava "stones" (important for fire-pit use as rocks have the tendency to expand and explode) and the ceramic logs.
The fire-pit is presently fed by poly tubing. Eventually, we might upgrade to 1/2in galvanized pipe for the longest runs, but for now it's a very well functioning initial prototype.
An on/off valve is plumbed in a convenient location and is fed by a 20# propane tank. I created a Meranti (marine-grade luan plywood) and Batu-topped box to hide the tank. I might eventually paint or solid-stain the box, but finishing with oil was very time-efficient.
All in all, the broiler pieces were about $300-$350, paint was another $25 and the fire-pit itself was $75, so all-in we're at far less than $500... not bad for a restored, converted fireplace/fire-pit that normally sells for more than $2,500. There's still a bit of fine-finishing to do — the porcelain chips very easily and needs to be sealed... but all in all, I'd consider it a finished project.
Good luck with yours!
Equipment — in no particular order. I'll screenshot the AMZ cart versus direct links — not to be cruel, but there's a bit of investigation and DIY-cred that comes from doing a bit more than clicking a few links. Use my shopping cart as a guide — not a parts-list. A few things to note:
- The adjustable pressure regulator is essential in getting the right flame height — a 20PSI adapter is enough
- The mixer-valve for the propane is a nice addition... it makes for a more robust, soot-less flame
- The fittings will need teflon tape and/or pipe-sealant (dope)
- The keyed valve is optional as the tank and requlator both have shut-off features.
- The tank-box (hideaway) was designed on the fly... but I tend to build boxes, so it was an easy task. It's also very much like the worm bin I built a few years ago. If I had Eichler-siding handy, I'd have probably used that.
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