Adventures with oven modification

[Roy M]

A couple years ago, I had a Magic Chef eye-level oven with lower level range burners on my boat, which, being a multihull, allowed such an arrangement. It was a wonderful setup and fit my galley perfectly, as well as performed quite well. The only problem was that, being an RV product made of porcelain-coated steel, it would need to be periodically replaced with a new stove due to rusting from the saltwater that splashed out of a pasta pot on the stove. I grew tired of throwing money away like this and looked for a marine stove in this configuration. None existed, although in a conversation with someone at Force 10, I was told that they had considered it and decided there was too little demand to warrant the investment. So I thought I'd try to build one. Having a bit of money, at the time, I bought a new Force 10 four-burner because I really liked the oven door arrangement where it disappeared beneath the oven, and the other parts seemed well built. I am in a unique situation, being a guy who has spent much of his life messing with boats, and having access to a spectacular range of tools, materials and exceptionally talented specialists in a variety of trades.

So, I took apart a perfectly good stove, chopped it up with some fancy cutting tools, had a friend who makes custom metal work assist with welding and sheetmetal fabrication, and another friend who does HVAC magic regularly assist with technical issues. The result is a hot-rod Force 10 stove. Now, for the legal mumbo-jumbo: Don't try this at home. Don't tell anyone you are doing this. Technical stuff is potentially dangerous and life threatening and should never be attempted by mere mortals. You have been warned. Only the insane and arrogant would proceed down this path.

Going into the final assembly stages of the stove revealed some entertaining details. As many of the parts sat in my shop for some time, they began to show deterioration due to humidity, ozone, cosmic rays and invasive mind probes by the NSA. Rust appeared on shiny little balls used to seal unused gas ports. The clip rings (little horseshoe shaped retaining rings with a pair of holes to open them), holding the valve stems in place, began to rust. I was surprised that such shoddy materials would exist on a quality marine stove. The electrical switches that controlled the piezoelectric igniters (the click-click-click thingies on the stove), began to break down, even though never used. And worst of all, my brilliant idea seemed doomed because the thermostat bulb that is located in the top, back of the oven, now wasn't long enough to reach the oven control switch in the new, lower position. And to top it all off, the cheesy, yellow fiberglass mat insulation that surrounds the oven had become compressed and useless over the long period of waiting to be reassembled. What was to become of this nifty experiment?

Okay, so much for the melodrama. It turns out that gas stoves aren’t that amazing or complex. They’ve been around for a long time. And marine doesn’t always mean it is impervious to the elements. I have been learning some new tricks that are now being implemented into my tricked out galley stove. First, like in cars and rocket ships, parts is parts. The valves connect to a supply manifold, small pipes transfer the gas to individual burners, little parts ensure that gas flows when there is heat and shut off when there isn’t. And heat can be made more efficient with smart insulation.

This last part is really interesting. All stoves are insulated, mostly with the cheesy fiberglass stuff similar to what’s in your attic. Over time, with the heating and cooling, and with the infusion of hot grease in the air, the strands of insulation begin to mat down and deteriorate, losing the heat-keeping qualities they once possessed. This happens in all ovens, but being contained within the walls of the stove, we never see it happen. In the meantime, the galley (or kitchen, for the landlubbers) gets overheated, the gas companies get richer, and stuff takes longer to cook (and at a higher temperature setting) than it used to when the stove was fresh and shiny. But, what can be done with such mysterious mechanisms sealed from public view? Enter specialty insulations. It doesn’t have to be as complex as the tiles of the space shuttle, but it’s the same material, more or less, made of ceramic fibers. It’s called FiberFrax, and comes in rolls and sheets, as little as ½” thick (Ceramic Fiber Blanket Insulation, Fiberfrax Durablanket® - Industrial Insulation). Getting to it may be a bit of a challenge, so for the faint of heart, go out and buy a new stove or live with the heat losses. Mine will be simple to install since I installed a new sheetmetal exterior to my stove, and is attached with stainless poprivets.

The gas valves for the individual burners will be recycled, replacing the rusting parts (and monitoring them in the future for deterioration). The tiny o-rings that help seal the gas lines to the burner assemblies will be replaced by commercial ones. The oven valve assembly will be replaced entirely with another brand (and a longer thermostat bulb lead). And so, the show will go on. I will be sending updates as parts come in, and photos as I take them. Here are some of the original stove prior to being worked on by the good Dr. Frankenstein.

[Roy M]

Here are some pics of the valve parts that began to deteriorate:

[Roy M]

Current status: waiting for parts. The stove was scaled to allow my pressure cooker, the tallest pot, to fit easily under the oven.

[Roy M]

Here's some more info on oven insulation: ApplianceMagazine.comÂ*|Â*Thermal Insulation for Oven ApplicationsÂ*-Â*Supplier Innovations

[TeddyDiver]

Thanks for sharing! Great job..

[Roy M]

Update: I was able to identify the manufacturer of the oven thermostatic control valve, which is manufactured in Italy. It's a SABAF, and according to its website, a Model 23 with two thermocouple ports (one for the oven burner and one for the broiler). Replacement units are available from the stove manufacturer in Surrey, BC, Canada, or from Sure Marine in Seattle (suremarine.com). I sent an email to the Italians asking if they could supply a new valve with a 60" (150 cm) thermostat, instead of the supplied 36" tube. This would allow me to keep the oven control valve in its normal position. In the event this isn't possible, I have already confirmed I can fit a satellite box on the right side of the oven, and use the existing hole in the stove front to mount a momentary igniter switch, as was suggested by Sure Marine. While I'm waiting for parts I will begin the polishing of all the metal so as to dazzle people who think that stoves normally come this way.

[Cheechako]

Interesting project. It's always been my impression that a "marine stove" is nothing more than an RV stove with stainless exterior. Is that your impression?

[Roy M]

Hi Cheechako! I was up visiting my mom last week, and hanging out at the Train Wreck. No, almost everything on an RV stove is ordinary steel: the metal is either chromed or porcelain coated. After a few years of boiling salt water (lobsters, heating dishwater, making pasta, etc.), it's a race to see which parts fail first. That's why I chose to plunk the money down for the Force 10. Although I have been mildly disappointed at some things (mostly, steel parts on very few pieces of valve hardware, and the housing for the broiler head), most of the stove has proven robust. I know, since I have COMPLETELY disassembled the entire stove and rebuilt it. One of the coolest features is that I can get to all of the spaces where the cheesy insulation was used. I will be able to insulate everything, PLUS, I will be installing a ceramic plate in the oven heat shield to provide more even heat distribution, for when I start baking cinnamon buns in Paradise to trade for lobsters, loose women and extended visas. The other cool part is I know what spares I'll be needing (not many), and have relocated the battery holder and igniter assembly to a more accessible location. One of the nicest features of the stove is the oven door assembly. I have a 12" square Bomar hatch directly above the opening of the door to provide terrific ventilation when broiling, and a stainless steel heat shield framing the hatch and above the oven. There is about a foot of air space behind the stove, and the entire stove footprint lies over the starboard underwing, with a snorkle valve at the low spot to drain any possible propane leaks over the side. I like to cook, and this stove location and format really works nice, but only for a multihull, or maybe a powerboat, that doesn't need gimbals.

[Cheechako]

You should have given me a call. Yeah, I should have said RV stove with stainless sheet metal, not "exterior". But the working parts are not really special marine designed right?

[Roy M]

The problem is that most of the stove is genuinely marine-grade. The valves and stove units are largely marine-grade, with some minor, but somewhat important, parts ordinary steel or aluminum. Frankly, I don't know of any stove that is completely ready for prime time. So, the decision to go with the carcass of the Force 10, and hotrod the rest, seems to have been the best of all possible options. Time will tell, someone may come online with new info and suppliers. NASA could have designed something better, but we know about the toilet seats and other grand adventures that resulted in that noble (and successful) experiment. In the meantime, I am basking in the pleasure of having a truly unique stove. There is, for the moment, no other like it in the world. But the Chinese have probably been listening in and will produce one for Alibaba next week. And inform me that I stole their design. I'll let you know the next time I'm up north and we can catch up on the state of regional brewing, the oyster varieties that are emerging, and the latest gossip about boats sinking in Anacortes.