Stove New Vht Paint For Cast Oem Cooktop

There's been a couple posts about what to do about rusting burners or a cooktop switchout: Rusting burners.... What to do to fix? and Stove - " Carolina Cooker " Switch-out Problems

I've just attempted what I believe to be one of the few (sort of) practical, partial solutions to the problem. If it's even a problem. I don't know. Most likely a First World problem.

This is what our OEM was looking like:

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And I wasn't terribly happy with the valve controls. I was hoping to replace it with a vintage Griswold 202 that I also just refurbed with a high-temp, non-bake paint:

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However, it doesn't fit the slide-out, and the controls lack, (how should I say?) finesse. Great for boiling a pot of corn. Not so good with a low-temp, controlled cooking and flame adjustment. I am also dealing with significant gas leakage at the cone valves. (I have a possible solution for that one and will post when/if I get it taken care of.)

I got a new Carolina Cooker, thinking it would be the same as the OEM casting. Dimensions are the same, and parts are interchangeable. But the cooktop casting is terrible, and mine arrived broken. I wasn't too worried as I was really just after the needle valve controls and burners:Cast Iron Stove, Double Burner Stove | Carolina Cooker which fit the OEM cooktop.

I resolved to re-paint the OEM cooktop casting and install the new burners and valve control.

After a lot of time researching the best coating to apply, I landed on this trio:

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They require a triple baking regimen to fully cure: 30 min at 250F, 30 min cooling, 30 min at 400F, 30 min cooling 30 min at 600F. I started out thinking that I had to do that for each coat:

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... until I found buried instructions on the interweb about applying all coats one after the other with 10 minutes inbetween, and then baking (as above) as soon as all those coats are dry, which is about 10 minutes.

My choice of BBQ curing was a compromise. I knew I wasn't going to be able to hit the final 600F. But I didn't want to heat up, and stink up, the house either using the oven.

Attempting to cure all parts at once was a mistake, as the cooktop closest to the BBQ burners, got smoky, despite me doing a deep soap-and-hot water clean to the BBQ beforehand:

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When I realized that the top rack gave the most even heat, and no smoke/scorch, I ran into issues with the clear-coat coming out uneven:

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After many re-coatings and curings, I finally got it to where I could live with it:

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Burner on the left is about "Medium-Low", while the one on the right is at "High" with lots of air flowing past the control screws.

There are some differences between the OEM valve control and the Carolina Cooker controls, in that C-I installed a 90 deg brass fitting to meet the hose. I wasn't able to replicate this and was forced to do a double-back:

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The 180 bend isn't too bad and I was able to install a hose clamp, similar to what C-I uses on the left side, to support the hose and prevent any abrasion that might occur against the nut:

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I used the Carolina Cooker burners, despite them being slightly smaller and not quite as robust a casting, because the CC valve control won't fit on the OEM burners. It is a different design where the venturi inserts. There was also enough slack in the gas hose to pull the extra I needed to make the 90 deg bend.

I didn't like the wing nuts on top of the OEM casting, so I inverted them. Do not attempt this unless you like Chinese puzzles:

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This required covering a wrench with sticky tape, placing the wing nut on the tape and maneuvering it into position, since hands and fingers don't fit. removal is easy enough, though.

I have no illusions that this will continue to look new forever. After a few minutes on high, the pot supports were already getting blackened and losing the clear coat sheen:

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As a recap:

1) A propane BBQ might give you higher temperatures. I used NG.
2) Clean your BBQ well and use the the top rack.
3) Apply all coats with 10 minutes inbetween and start curing with heat within an hour of applying the last coat.
4) OEM cooktop has/had a ceramic enamel finish. How this treatment will stick to it is anyone's guess. The ceramic can't come off, if you were hoping to get back to bare metal.
5) The VHT manufacturer also describes "on-car" curing as an option, since these paints are for headers and manifolds. I have to believe that the specific baking regimen I used will yield somewhat better results.
6) Don't expect miracles.
7) Budget for more time than you think you need for touch-ups and do-overs.
8) Soap your connections for leaks.

 

Forgot to add: The needle valves are so much easier to dial in a desired flame. From Low to High it's about 1 1/2 turns. Whereas the OEM was 180 degree cone valve that wasn't at all linear in adjustment and was difficult to get "just right".

Switching out the cone valves to the needles was worth the cost of obtaining the entire $35 Carolina Cooker. Even though I had to throw the top away.