Replies

1. 
   Art_B. | Sep 04, 2001 09:20pm | #1

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   Since the resident chemists have not answered, here's one item.
   Have heard that using any kind of newspaper to start fires that contains colored ink will poison the Pt in the converter.
   Don't know the chemistry of this particular reaction, but the inks supposedly contain heavy metals and that any type of heavy metal (lead, zinc, cobalt, silver, gold, etc.) that gets into the fire can also poison the converter (e.g missed battery mixed in paper trash, metal buttons on disposed rags, galvanized nails in pallets, etc.)
   Without (or maybe to)get a political discussion started, by the catalytic poison reasoning, if you are in acid rain country, Greenpeace would likely say your wood even has enough heavy metals to poison everything and everyone.

1. 
   Luther_Kuhlman | Oct 05, 2001 03:23am | #2

   *My woodstove shop gave me a copy of "Major cleaning procedure for cornings catalytic combustors". The procedure involves simmering the converter in a 50-50 solution of white vinager and distilled water.The procedure is fairly detailed and too long for my hunt and peck typing skills.Contact Corning's Woodstove components plant at 800-637-1644 and see if you can get a copy of it. If this fails contact me and i will try to sweet talk my bride into typing it up for you.

1. 
   David_Thomas | Oct 05, 2001 09:16pm | #3

   *Sorry, the resident chemical engineer didn't catch this one. I was out of state that week.A number of things can ruin a catalytic converter in a car, wood stove, or in the $50,000 air cleaning units I've designed and operated. As mentioned, heavy metals (especially lead) can irreversibly coat the platinum surface. The unit has $10-$20 of scrap value because it can be refined out again, but you can't do it. Old painted wood would be one source of lead. Don't burn painted or pressure-treated wood. Not just because of catalyst longevity, but because of the noxious fumes.Chlorine (from burning plastics) can reversibly coat the active surface. Several hours of normal operation should restore catalyst activity. So this probably wasn't your problem.High temperature can cause a recrystalization of the ceramic substrate. This reduces the surface area and the activity a lot. Most catalytic stoves have a thermometer for the catalytic and recommended operating temperatures. A few hours at 100F too high or a few minutes at 300F too high can permanently toast it. Since yours cracked, I suspect high temperatures (or physical shock). Once there is a crack in a monolythic element (versus pellets), many of the gasses go through the crack instead of reacting in the little passages of the honeycomb.I'm not sure if it happens in wood stoves, but I've had salts build up on the catalytic element. Simple water (or a weak acid) would remove chloride and nitrate salts, but carbonates are removed best with an acid, such as the vinegar that was suggested. I've also used 100% vinegar with good results. If you see fizzing and bubbling, it is definitely removing carbonate salts. Either way let it soak for an hour, rinse thoroughly with batches of water and let it dry completely. You might as well try this, as it is the only homeowner-level fix that might work. If it doesn't help, you're where you were to start with - needing a new catalytic element.It doesn't surprise me that you burned A LOT more wood with the damper open. Not only is a lot of room air being heated and then lost out the chimney (by opening the damper), but by bypassing the catalytic, you are not burning the smoke, creosote, and carbon monoxide that you did when the stove was operating properly. 7 years is not an unreasonable life for a wood-stove catalytic. With meticulous operation (never any temperature exceedances, nothing but clean wood, etc.), it might last forever (my automotive catalytic has gone 280,000 miles and works great). But in the real world, 7 years ain't bad. -David

2. 
   Frank_H._Biscardi | Oct 05, 2001 09:20pm | #4

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   I just replaced my catalytic converter in the woodstove. It cracked last year. I couldn't push in the damper without affecting the draw. Therefore I ran the stove with the damper open. I burned about 2-3 times the amount of wood I normally do and made a huge amount of smoke.The smoke appalled me and I am not even particularly"green".

   I dropped about $150 on the converter and the installation. What can I do to keep from ruining this one. NB I got about 7 years out of the old one.

   Thanks

   Frank