Brilliant! Thanks! I was already noticing premature decay of my secondary air tube in a ceramic board batch box after just a few fires (one of which I admittedly allowed to get way too hot.)
Thank you both for the kind words. William, I have not slit these. I suspect they are more durable as a complete pipe, perhaps with a small performance trade off. Needs to be A/B tested to know for sure. I might get to that this winter.
If you let the top rim remain intact then start the slot about a half inch or more down from the top rim, it might serve as a viable compromise for longevity. I just ordered one and I’ll try both. Also I think cutting it on a slant might help too?
Another option: 1.67” diameter marine grade 316 stainless tubing and separate mount. The tube can easily be removed from the stainless steel flange base and replaced if/when it eventually burns out. Steel tube thickness is 2mm/ 14 Gauge. (It’s simply marine grade handrail tubing and hardware.)