Replacement Gas Gauge

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[edtbjon]

I did replace my original gas gague, as it all of a sudden was busted. (I found a very nice, though expensive one locally.) For gas (pressure) usage, I've recently started with a low charge temp approach (see that thread), where my TP is at around 80-85C/175-185F giving me more room to "really" hit the gas. But I still never go above 3.0 kPa at any stage of the roast with a 400g charge. I will try to replicate a good 400g roast with 500g, but I cannot imagine that I'd go above that 3.75 kPa (even though both my regulator and gas gague goes up to at least 6.0 kPa).

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[edtbjon]

Just to elaborate a little bit. Even though some kind of fan control isn't "standard" equipment I take it most of us do use some kind of electric/electronic fan controller.
Now more than a year ago an early RoastOfTheMonth from MillCityRoasters featured Joe Marocco's personal Huky500, where he roasted with only the standard fan and the damper. During the full drying stage he used no fan at all and he had some good arguments for doing so. I tried that approach and found that I could turn the heat up to crazy levels without any real effect. What I did was running the burner very "rich", i.e too much fuel and too little oxygen.
Back to the fan controller. IMO it's important to find out at what setting (voltage - speed - ...) the fan starts creating a negative pressure in the drum (simply put: when it starts sucking some air...). That is usually done with a cig.lighter at the tryer/trowel hole and the procedure is described in detail elsewhere on numerous places. Anyhow, that is what I call the "zero" setting for the fan. (It seems like most of the folks who are using Variac transformers finds this setting at around 30-40% (or Volts for you Americans   .)
Just rising the fan up to that zero setting does create airflow past the heater and it makes the heater much more effective. The effect is quite dramatic.  The burner will get even hotter up until around 40-50% fan efficiency, after which the fan will start to cool things a bit.
In practice, I can pump up the gas flow to 4, 5 or even 6 kPa without it having any corresponding effect to the actual heat produced unless I add some air into the mix. With just a small amount of airflow (between 0 and 10% from my calibrated "zero") the burner becomes much more effective.
How to plan for your airflow during the roast is another discussion and there is plenty of information on that subject out there too.

[ContralaCorriente]

Hi all, curious to know what gauges people have used as replacements for the stock 10kPa? I would like something in the 5kPa range, though maybe 3.75 would do. I am more concerned with ensuring that the threads match up to match on the IR burner.

[SusanJoM]

qarl directed us to a gauge a couple of years back and I think it's still the most common replacement

https://www.hukyforum.com/index.php/topic,41.msg154.html#msg154

[ContralaCorriente]

Thanks, Susan! I had read that thread, but then it mentioned the threads not being the same, so wasn't sure if if anyone had found a gauge that exactly matched more recently .

[SusanJoM]

Ah, well that's a good question.  I don't think I have seen any mention of anyone using any other gauge;  I also have seen no mention of anyone at all having trouble with that one.  Gas teflon tape is a good idea. 

If you find a better one, please be sure to let us know.