PC baking, getting the temperature setting correct in ovens.

[prs]

As is pretty much common knowledge, the dials on ovens, even high end ones, often do not read true. Non convection ovens also have temperature variation depending upon location within the oven. External PID controllers can have conflicts with internal thermocouples that are in the ovens. My lead pot is PID controlled, but my small convection boolit PC curing oven is convection and I rely upon the oven's dial setting. However, my reliance is one of those "trust, but verify" affairs. I use a bimetal oven thermometer, one that is highly rated by professional chefs for high temp cooking. It is inexpensive and convenient:

http://www.amazon.com/Cooper-Atkins-24HP-01-1-Stainless-Thermometer-Temperature/dp/B00125TABM/ref=sr_1_2?s=home-garden&ie=UTF8&qid=1408816340&sr=1-2&keywords=oven+thermometer

Another option for those that prefer the built-in configuration is this, I have a similar one on my outdoor grill, but not through the wall of my PC oven:

http://www.amazon.com/CHARCOAL-GRILL-SMOKER-GAUGE-THERMOMETER/dp/B007JI3HYC/ref=sr_1_2?ie=UTF8&qid=1408816984&sr=8-2&keywords=barbecue+thermometer

Set the oven dial where ever to get the temp the job needs and then use a temporary mark to mark the dial face or the oven knob, if necessary. Mine was pretty close, only minor fudge factor so I can eyeball the correction. Temporary because the variation can change over time. Re-check once in a while. This gives you air temp within the oven, use sufficient time of bake to get the boolits heat soaked to that temp. Using two racks within my little oven with almost 7 pounds of lead (240 200g .452 SWC boolits), I give the bake at 400F another 25 minutes once the powder melts to a gloss. Total time is about 33 minutes. Not bad for a small oven and large load, right?

prs

[Southern Son]

Thanks for that, I was about to put my old lead thermometer to use doing this, but that would have left me without a way to monitor temperature in the mould oven. I might look into 2 of the BBQ ones and fit one to the oven and the other to the mould oven. Would be easier than balancing the lead thermometer in the mould oven, or having it hangin out the door of the boolit oven with the door open, letting out the hot air.

[snuffy]

My question is it really that important? Isn't close good enough? It must be, I haven't had problems setting the dial to 400 and leaving them in there for 15 minutes. That's for HF red in my 10 dollar goodwill convection oven. Once the coating has gone shiny, meaning it's cured, I feel that's enough. If I'm wrong then edumacate me!?

[prs]

Snuffy, if you are happy, I am happy. It may not make a bit of difference. I don't think my little oven could get it done in 15 minutes total with a heavy load in it.

prs

[bangerjim]

I use a ~$100 convection oven and have analyzed it's temp profile with accurate t/c's and IR's. It maintains 400F (on the dial!) within 5 degrees either side. I load it with 2-3 racks of up to 320 boolits at a time and it stabilized to 400 in as little as 4 minutes, and when ALL the powder is shiny, I start my 10 min timing cycle.

Temp is not that critical, but many are relying on those cheap ovens to be accurate and the dial can be off as much as 60 degrees! That leads to under baked boolits that do not pass the hammer test. Yet people swear they are baking at 400F! And then they increase the bake TIME....which does nothing but waste power.

Try to stay as close to 400 as possible. I have found higher does not hurt....lower does!

banger

[Yodogsandman]

My $7 yard sale toaster oven does a fine job! I only do small batches of rifle boolits (88 ea) at a time. I HT at the same time and quench when the PC's cured. What works...works. What's to question if the PC cures, right?

[Beetmagnet]

.

. I have found higher does not hurt....lower does!

banger

Unless you melt the bullets... lol. Ask me how I know.

I used two oven thermometers to verify temps, and then I marked the dials. I haven't moved them since December... everything s fine.