BK And Lady BK Go To Woodstock

[Slow1]

Did they mention anything about the new steel cats to be prone to warpage? I've heard a few people with that problem but could be operator error. That's good they are keeping the price the same, I was thinking they would be twice as much. I'd like to try one but don't think I'll need one for a few more years.

The only comment about warping came in the context of why ceramic cats break up. The context was that in some stoves (other brands) the cats are not supported as well and/or are attached to parts of the stove that will cause torquing. This may be the result of extreme conditions in the stove (i.e. overfire) or even in some cases simply uneven heating of the metal in the stove. At any rate, if a ceramic cat is bent/twisted etc (especially while very hot) it will crack and/or break up more easily. Makes sense to me. The implication of the conversation of course is that the cats in the FV are better supported and not subjected to these strains.

Now taking this bit of information and applying it to your question I would have to guess that we don't have to worry about it. Looking at the physical layout of the steel cat it looks like it should not have a problem with warping - they have the familiar honeycomb design that the ceramic has and they are rather thick so I'm not sure what axis they could warp on (i.e. mechanically it appears that all surfaces are very well supported). I'm sure time will tell (nobody to the best of my knowledge has burned one for 5 years yet) and of course WS has a reputation to uphold and I see no reason that they wouldn't stand behind it if a problem were to pop up later.

 

[Battenkiller]

It seems that this K under temp will bind in some way with the ceramic and weaken it leading to the failures that commonly are associate with physical failure of the cats.

Funny, I walked away with the erroneous notion that it was the noble metal catalysts that were somehow being poisoned by potassium. So it's the ceramic itself that's being damaged? I wonder, then, why are they making this new screen for the stainless cats? Do you know if stainless is susceptible to the same type of damage?

AFAIK, fly ash can't be totally avoided. It is always a small fraction of the exhaust. Since it is extremely fine and light in weight, it seems to me that the more turbulence inside the stove (a good thing), the more it will appear in the exhaust. The stronger the draft, the more will go up the flue. If there is a cat in the way, at least some fly ash will accumulate on its surfaces. What I took away from my talk with Tom is that wood that makes a lot of ash will make a lot of fly ash. Ash content is dependent upon species, but is also highly variable depending on where and how the tree grew. I do know that, in general, conifers produce less ash than our beloved hardwoods do. A rallying cry for the pine enthusiasts to gather recruits, perhaps?

 

[Slow1]

Funny, I walked away with the erroneous notion that it was the noble metal catalysts that were somehow being poisoned by potassium. So it's the ceramic itself that's being damaged? I wonder, then, why are they making this new screen for the stainless cats? Do you know if stainless is susceptible to the same type of damage?

Which is why all this "I heard this, I heard that" reporting is rather unreliable when it comes to the details. There likely is some element of both involved and perhaps one (or both) of us is mixing something up. I'd love to see some published reports on their experiments including methods and conclusions but somehow I suspect that isn't going to happen.

However, I do believe what is useful here are the common themes - I think we both got out of the conversations that thermal shock isn't the big killer of cats we once thought it was and that potassium is bad... and most importantly the folks at Woodstock are doing a heck of a lot of research into some minute details of the stoves - not necessarily taking everything for granted with the goal of engineering the best possible stove they can. Further they are applying the results of this research to not only the new stove in design but also pushing it back to existing stoves as appropriate (i.e. SS cats).

I think this is great and I'm thrilled to see that WS is doing this as it gives me great confidence in not only their future products but the future of their existing products and by implication the company as a whole (thus I expect they will continue to be there to support my stove).