Cutting a hole in the Ideal Steel Radiator above the cat?

Folks,

I hope this note finds you well. Please excuse my tragic computer skills as I tried to do a search on this and failed miserably. The question relates to cutting a hole/holes in the Ideal Steel radiator directly above the cat. The radiator is dropping strange red deposits on the cat, it is corroded and the concept of heating a baffle plate instead of the stove top seems inefficient. There were some references to a stainless-reinforced radiator which I would be interested in learning more about. For the time being, assuming a fan blowing on the cooktop, what are your thoughts on cutting a hole in the center of the radiator? This is conceptual only and I am not going to embark on such an endeavor without informed opinions. Thanks for your help.

 

I believe there was an updated radiator for the IS. The earlier ones were flaking and drooping down after some hard hours on it.

I'd wait for a few the IS owners to chime in on this one before getting a drill bit out.

 

That is really a very good idea I think but there are a couple of caveats, one or more may prove a 'deal- killer'.

Several of us have noticed lately that the stainless steel plate bolted to the bottom of the stove top plate, the one above the radiator, is warping quite a bit. It is because it is exposed to such high temperatures, even above the radiator. If you cut a hole through the radiator, that absolutely will help in saving the radiator from getting and staying so hot, but it will also increase the heat on the next plate above and I believe it will increase the warping of that second plate. So you will be trading the warping and flaking of one part for another being warped.

That said, if you had a sufficiently large fan on the stove top and removed the center round plate from the stove, you <might> be able to keep the temp. of that second plate low enough to prevent warping. If that will work, it would also have the advantage of putting more heat into the house, making the stove more efficient (it will lower exhaust stack temps.). The only way to know would be to try it and watch the various temperatures either with thermocouples or possibly and IR heat monitor.

Brian

 

Pardon if I'm missing something here. But if your gonna cut a hole in the radiator, why not leave it out all together?

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I view the plate as a low-cost consumable part. The scaling isn't a big issue in my view. I didn't run the IS with a stainless plate, but the AS stainless wasn't flaking during the amount of time we ran it.

As noted above, it serves a critical purpose in protecting more expensive parts above it

 

Yes, the first two posts are exactly right I believe: as I said above, cutting a hole in the radiator will absolutely project more heat (higher temperatures) onto the bottom of the stove top, the under- plate of which is already warping due to excessive heat. If the radiator is just removed, that will do what cutting a hole in the radiator will do only do it more intently: it will project even MORE heat onto the stove top, which again, even with the radiator intact, is warping from too much heat.

I do not know what VF CFB is but again, the design of the stove is such that a huge amount of the heat produced by the stove, all the heat in the firebox gasses, and all the heat produced by the combustor are concentrated directly onto the radiator, a piece of something like 3/16" thick carbon steel about 1" above the combustor. The radiator runs 'red', well over 1,000F, for hours and hours at a time. It gets so hot it warps to the point it must be replaced or straightened or it cannot be used anymore (the 'bypass' will no longer close). The radiator is directly below the stove top, perhaps 2" below it, and the stove top has a thin stainless steel plate on the bottom to protect it from the intense heat from the radiator. That plate too is warping on Ideal Steels, again due to intense (though not 1,000F range) temperatures, for extended periods of time. So if the material you are suggesting restricts more heat than carbon steel, it will behave like a thicker radiator and throw more heat up the flue, if it transfers more heat than carbon steel, it will further overheat the stove top.

Of course, the goal is to get all of that heat into the house before it goes up the flue. Removing the radiator would result in my heat on the stove top, almost certainly resulting in more heat radiating into the house but also certainly resulting in the stove top warping instead of the radiator. The radiator is needed to absorb and distribute that tremendous amount of heat I described earlier. Cutting a hole in the radiator is a mid- step between removing the radiator and leaving it as- is: it will increase the stove top temps., <should> result in more heat coming off of the stove top into the house but also increasing the amount and speed of the stove top plate warping.

The underlying problem is that there is not sufficient distance above the cat., and insufficient square area heated by the cat. (and flue gasses) to disperse the heat into the room before some components are overheated to too high temperatures.

There are a couple of ways to deal with this, one being an idea I had when I bought the stove and one that Woodstock actually tried: remove the radiator AND the middle of the stove top and instead put a piece of glass in there. That would allow tremendous amounts of heat to radiate out of the stove and of course, ceramic will not warp. On the other hand, glass does break, and that would be disastrous, but a cage of some type outside and over the glass <should> protect it sufficiently. Still, glass on top of anything that must be contained, such as a woodstove exhaust, is risky; if the glass is broken, the stove absolutely will vent into the house.

Another simple solution is to just make the stove top plate into a pyramid shape or raised rectangular shape. That WILL work, but will drastically change the size, shape and looks of the stove, as well as require a new EPA certification. It is effectively making a new stove out of an I.S. But it is the inexpensive solution that would stop all the warping as well as producing more heat in the house (increasing the stove's efficiency).

There are other, more involved ways also; methods to move heat away from the radiator and out into the room, either mechanical such as a heat sink, or using physics, such as a heat- pump would also work but would be more expensive, complex and so forth. And again cause the stove to require re- certification.

As can be seen, I have given this a lot of thought because I too would like to fix these little issues as well as increase the efficiency of all things: if I could get the exhaust gasses down to 100F, I would wonder how I could get them to 90F and grab that 10F going up the stack. Not practical but the point is that I want as much of the heat out of my fuel as is reasonably possible.

Brian

 

It’s my understanding the updated radiator fixed the warping problem, or generally fixed it if not 100%.

I know there has been much discussion about getting more heat from the IS. Honestly, I’m not sure how much cooler the exhaust can get and still create draft. I’m on the original cat and the exhaust temps hang out around 200f. With good burning practices this stove is barely putting heat out the chimney already. I do like a good theoretical conversation about getting that last percent efficiency but it is nothing I would ever stress over. I hope people considering the IS don’t get the impression the stove needs to be modified.

 

OK, that is a heat reflector and has very low conductivity: if a layer were used under the radiator, it would reduce the radiator's temp. and as a result, probably eliminate its warping. But it would also insulate the heat inside the stove and end up reducing the stove's efficiency by raising the flue temp. Exactly the opposite of cutting the hole in the radiator.

There are no right or wrong answers here IMO, just different ways and methods that yield different results. But it is an interwoven collection of variables so changing one may well change more than one other thing. What I believe most of us, and I know I am seeking, is the best way to 1) burn wood 2) burn wood cleanly 3) have the stove and all parts last as long as possible and 4) get as much of the heat out of the fuel as we can.

And I do not believe there is so much a 'correct' way as there are better ways that can be used / added to what we already have. Sort of like cars: they were not perfect in 1917, and they are not perfect in 2017 but they ARE one hell of a lot better. And no single change made the difference, the results we have today are the result of literally millions of inventions, innovations, problem fixes, and more than a few steps backwards.

Back to the I.S. stove: it is a great machine, and an outstanding design in my opinion and experience. I certainly do not want to give the idea that it is defficient in any significant way or 'needs' fixing / altering to work well because it does not. But people like us, who spend time thinking about and tinkering with these things just cannot help ourselves and have to tinker. I am certain that if I owned a [put brand and stove type here] I would be twiddling with that one, and find a group of like- minded people on the 'Net doing the same.

Brian

 

I really like the idea of replacing the area directly overlying the catalytic combustor with a ceramic glass insert, the same material they use for flat top glass stove tops. It would stand up to abuse (they cook with huge pots and cast iron on it already), it could easily take and outwardly radiate the heat well, the technology to insert it already exists, it’s a proven technology, and it would create a true cook top on the IS.

It’s already being used in rocket heater cook tops directly over a 2000•F flame.
Walker Full Masonry Cook Stove

 

Woodstock has one they had been experimenting with on their mfg. floor. They said it worked OK but the glass got dirty. Fine and well but I have to believe that 1,200 F plus degrees of heat coming from a healthy combustor would clean molten aluminum from the ceramic (glass). I tried to engage them with some 'in the field' R&D but no- go.

I would LOVE to try one myself but have not quite gotten there yet. Still, a new stove-top with no S.S. liner and a large piece of ceramic glass would go a long way to fix the existing quirks of the stove as well as letting a huge amount of heat, in the form of IR, out of the stove. And even if the glass got dirty, the deposits could not survive one heat cycle of an active combustor, or at least that is my opinion.

Woodstock is a great company and they make great products but every now and then, I feel the urge to jump back into stove development because I believe there is plenty of room left for improvement (not knocking anyone, just saying). And I still think there is tremendous potential with an in- the- house gassifier as a wood-burner: cleaner than even a cat. stove w/out the cat.

Brian

 

I tried to get Tom to explore rocket heater technology (in essence a form of wood gas burning) but he said he had his hands in too many pots already.

 

For an experiment, I wonder what a piece of that ceramic glass big enough for the top would run? Or where to buy? The top comes right off and glass would sit properly on the stovetop by gravity, resting on the rope gasket.

Hmmm...

 

Rocket Stove you say? OK, now I am interested Got any more info. you are willing to share?

Brian

 

At first I was going to say that I doubt that would work simply because it would be so large, but then I thought of ceramic cook top kitchen stoves. They work, so why not? The glass (ceramic) would have to be quite thick to be rigid enough (Easy Boys!) but I think it would work for testing purposes. It certainly would be easy to try although a piece of ceramic glass that large and thick enough might well be prohibitively expensive.

It would not work in any product to be sold though, the risk of breaking the glass is just too great. For a commercial product, the glass panels would have to be smaller and very well protected; perhaps a steel grate that the IR could get through but would stop all but fairly small objects from striking the glass. If multiple but smaller panels were used, the stove would probably survive one broken pane without leaking smoke and fire into the house, assuming it had sufficient chimney to maintain a positive draft down through the stove top.

Brian

 

No, that was pretty much the end of it with Woodstock.

I’m personally moving forward with a rocket heater supply company online. I’ll be stocking various thicknesses of ceramic fiber board as well as insulating fire bricks in large 24”x9” size for building the firebox and risers, stainless pipe and hardware for secondary air supply systems and some other hard to find materials. I have some simple designs for a “shippable core” kit, something they’ve been clamoring for in the rocket heater community.

I’m heading down to North Carolina the first full week of December to build two masonry rocket stoves. A guy down there hired me to travel there, design and build them in his farm house.

 

My radiator is warping/sagging as well. Time to shoot an email off to Woodstock and see what the options are.

 

When I was at the Wood Stove Decathalon in DC, Tom was showing TurboDiesel and me how much draw the stove had. He actually lifted up the plate with the burners over the cat and NO smoke escaped, even though it had a roaring fire and the cat was red.

Even if the ceramic glass insert cracked, I doubt it would fall apart, and I don’t think it would leak. If I still had mine I’d seriously consider replacing the center round burner stainless steel insert with a piece of ceramic glass on top. The stuff can be cut with a wet tile saw and I have one of the ceramic glass tops to play with and a wet tile saw if TurboDiesel wants to experiment. Just put some flat gasket on top the stove around the round hole, or firebrick cement from a caulking tube, or make some refractory mortar from fire clay and fine sand (1 part clay to 3 parts sand plus water, which we use to seal this glass in rocket heaters) to get a good seal, and place a piece of ceramic glass over the hole.

 

I'd love to replace the whole top with ceramic glass.
It's not fragile.