Vintage Cast Iron Stovetop Refurb Dual Fuel

In a couple other posts about the C-I stovetop I mentioned that I acquired a vintage Griswold cooker in an attempt to retrofit it to the trailer. It didn't work, as it was sized too differently. But I was able to to tear it down, refurb it, and turn it into a dual-fuel cooker, that can be be used with a either propane tank or natural gas.

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But not using both fuels, or both burners, at the same time.

The stove came with two propane-sized orifices, stamped #73. These have a small hole and are only suitable for propane that is being delivered at 11" WC. If you try to run household natural gas through it, it simply won't light; household pressure can vary, but is typically only half of what propane ends up being at the end.

I made a bunch of quick-connects so I can easily switch between the two fuels:

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When it is running off a propane tank with an 11" WC regulator (that you see in the pic above), and the #73 orifice, it gives a decent flame at 2/3 "on":

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In order to run natural gas through it, I took one of the orifices:

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... and drilled it out to 1/16th" on my press. This allowed enough flow through at the lower natural gas pressure to mimic how the other side burns. I didn't take a pic because the flame was essentially invisible. (If you're going to do this, experiment by working your way up to the properly sized hole, as your house pressure may differ from mine.)

Obviously, I can't run both burners at the same time, but I preferred flexibility over capacity. I didn't think I was going to be using both burners at the same time very often anyway.

The valves are conical and require some greasing with a specific grease which also acts a leak sealant:
https://www.amazon.ca/gp/product/B00PDFDU1I/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

I used a high temp paint, which didn't require any heat-curing:
Stove Bright® High Temperature Paint | FORREST Technical Coatings... just to see how it would differ from my recent attempt at re-painting the Camp-Inn stove with a baked-on ceramic coating.

I doubt we'd take this with us and the trailer. But I throw this out here as some don't bother at all with the OEM trailer stove, and wish to have something a little more portable, or versatile. Meaning: they like to cook on the picnic table or the C-I side tables because their T-Rex arms don't reach all the way to the back of the galley.

And it's got a cool vintage vibe too.

There's no reason this can't work off the side propane port; you'd just need an 11" regulator on a hose like I have here as the side port delivers 20 psi, which is more than 40X what you need for the burner.

And if you do do a dual-fuel set-up like I have, conspicuously label your valves and burners for the appropriate fuel. Running higher pressure propane through a natural gas orifice will turn the burner into a flame-thrower. There is no way to easily mitigate this result by way of controlling the air-flow and gas-flow at the valve.

Switching out orifices is a 5-minute job if you want to keep your fuel choice uniform and/or use both burners at the same time.

 

Can't find those on Amazon anymore....

 

The cap orifices?

Or just generally: "They ain't makin' that kinda cast iron stuff no more. " ?

Since I acquired it, I've noticed that the few cast cook tops that have shown up on Ebuy aren't nearly as serviceable as mine was right out of the gate. Like they've been stored in a water-logged corner of a barn, with lumber and hay piled on top, and missing a leg. With those, you may never stand a chance of getting them operating properly, or safely again.

I was somewhat reluctant to drill out the orifice, as those aren't terribly common on-line, either.

On the other hand, the Griswold cast iron pans (they made lots of food-prep items, like waffle irons and meat grinders before closing up shop in 1957), are quite readily available and highly desirable. But because of their initial high quality and reputation, they can be quite pricey. Depending upon the year of manufacture and the style of logo stamp. And if they've been properly reconditioned before they go on the block.

I have 3 vintage Coleman lanterns from the '40's and '50's, from both the Wichita and Toronto factories, that also need my attention, to get them running properly again. More technical things to learn, and more legacy camping gear to will to the kids.

But they may need to do rock-paper-scissors when it comes to getting the Camp-Inn.

 

Steve,
Awesome restoration! I have a bunch of Griswald skillets in the kitchen - they are seasoned and our primary cooking pans. If you can find the miniature versions of the pans that were used by the salesman or especially a complete store display with all the miniatures - you will have hit a gold mine. Check out https://a.co/d/beoACMh a complete list of their products and value (although a bit dated from 2011).

 

You may have just sent me down the rabbit hole of no return.