Red Hot Cast Iron

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cmcramer

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Feb 19, 2007
123
www.cramersoftware.com
I know from reading this fine forum that keeping my VC Cat Encore at 600-650 griddle temp is a good temp for maximum performance and to prolongs the life of the stove. No glowing cast iron!

But what about the inner parts... like the andirons and that hood that hangs in front of the catalytic converter? They glow red every time I use the stove. Should I plan on regular replacements? That 'hood' is already scaled.....discolored....and warped! Year and a half old!

Thanks for any advice!
 
cmcramer said:
I know from reading this fine forum that keeping my VC Cat Encore at 600-650 griddle temp is a good temp for maximum performance and to prolongs the life of the stove. No glowing cast iron!

But what about the inner parts... like the andirons and that hood that hangs in front of the catalytic converter? They glow red every time I use the stove. Should I plan on regular replacements? That 'hood' is already scaled.....discolored....and warped! Year and a half old!

Thanks for any advice!
I ran my cat Encore for 23 years. My target was 400-650 for the top of the stove to the right and rear of the griddle. My andirons were in good shape when I scrapped the stove, but I don't recall them ever really glowing. The "hood" in the back eroded away over time, but I had seen that hood overhang get dull orange, rather than red, on many occasions. I had the stove torn down and rebuilt at 10 years, and replaced the firebox back panel (with the hood in it) because of that erosion. At year 23, it was eroded away pretty badly again. That hood gets very hot from the cat sitting so close to it. Enough radiant heat comes back through the opening to really heat up the hood overhang. I think the cast iron just gets very brittle there over time, and crumbles away when it gets hit by a split during loading, or other mechanical contact.
 
I have no first hand experience, but I've heard those stoves require regular replacement of the metal around the cat. I think it must be a poor design, because I haven't heard of similar problems with other cat stoves (although that's not to say there aren't others with similar issues). I would keep an eye on it, but it wouldn't surprise me if you're replacing those metal areas every other time you change the cat.
 
grommal said:
cmcramer said:
I know from reading this fine forum that keeping my VC Cat Encore at 600-650 griddle temp is a good temp for maximum performance and to prolongs the life of the stove. No glowing cast iron!

But what about the inner parts... like the andirons and that hood that hangs in front of the catalytic converter? They glow red every time I use the stove. Should I plan on regular replacements? That 'hood' is already scaled.....discolored....and warped! Year and a half old!

Thanks for any advice!
I ran my cat Encore for 23 years. My target was 400-650 for the top of the stove to the right and rear of the griddle. My andirons were in good shape when I scrapped the stove, but I don't recall them ever really glowing. The "hood" in the back eroded away over time, but I had seen that hood overhang get dull orange, rather than red, on many occasions. I had the stove torn down and rebuilt at 10 years, and replaced the firebox back panel (with the hood in it) because of that erosion. At year 23, it was eroded away pretty badly again. That hood gets very hot from the cat sitting so close to it. Enough radiant heat comes back through the opening to really heat up the hood overhang. I think the cast iron just gets very brittle there over time, and crumbles away when it gets hit by a split during loading, or other mechanical contact.

Dull orange is a better description - thanks.
 
I saw my VC NC Encore's andirons glow once. It was after I had just reloaded and apparently had wood blocking air flow around the box and the coals were raked to the front. That little space that is created by the convex shape of the front of the stove created a place for the heat to get trapped until I moved the load around.
 
I don't know that it is really a design flaw - but anytime metal starts glowing (and actually somewhat below that temperature, too) it's going to start building up an oxide scale. When that scale flakes off, the exposed metal will start to oxidize and fall off as well, continuing the cycle. This happens with all cast iron and steel regardless of stove. Eventually the steel will be all oxidized or 'burned up' and the part will fail. Usually the parts of the stove subject to the highest oxidation rate will also be the thickest sections and hopefully the mfr included enough material for many years of average burning. You might be able to minimize the effects by running as close to optimal air flow as possible without going over. Extra oxygen will just make the steel scale faster - but not many people adjust the stove every 5-10 minutes for optimal air just to extend a part from 7 years to 9.

Warping may be an improper design by not allowing enough space for the metal to expand or providing the proper gaps and seams. My stove originally had a lot of 'stitch' welding on the interior. The metal could expand between the stitches but was held by each weld. Made for some very interesting warping. When I rebuilt, I used solid welds so the entire piece expands/contracts as one.
 
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