Most people ARE NOT baking PC long enough

[Willbird]

Since I got my new computer with windows 10 I have been relearning what little I did know. Posting pics is something I havn't figured out yet. I used to do it all the time but now I have trouble getting pics into my computer let along getting them out. I coated my second batch of MP 359-125 penta HP today with Eastman ford blue & turquoise. Both colors turned out perfect. The hollow point made it easy to pick them up.

Bob

I use Imgur for posting pictures, they have an ap too but I do not use it much, it does work though.

Bill

[Conditor22]

http://castboolits.gunloads.com/show...es-using-IMGUR

[tomme boy]

Download them to this site and attach them. That way you do not need a hosting site

[Dragonheart]

You will need to resize the photos otherwise this site will not download them. I don't know what the actual limit here is, but if you do a typical "email size" that works quite well. Just select the above icon "insert image" then select a stored image on your computer and download to your post.

[Conditor22]

I believe the pictures have to be 200 kb or smaller
You are also allowed only a limited amount of storage for pictures on this site.
IMGUR is just easy.

[tomme boy]

I download 4M here all the time

[Willbird]

about 800 wide is about right too, if you link one too wide it really wrecks a thread. Narrower if it will get the point across is OK too. I usually crop then scale the width to 800, use Gimp to do that, the native Iphone stuff works good to crop but I never bothered to try to use it to scale.

[Crowkiller]

I was able to pick up some of my PC boolets after they hit steel on our range. The boolets were flat disks with powder coating on the base. I thought that was evidence, along with my hammer test, that I had it down.

I'll check it with powder to be sure!

[Lloyd Smale]

do you guys that set your oven at say 400 or 410 and check it with a thermometer and adjust to the point the thermometer reads 400 take into account an oven cycles. It has a low cut in and high cutout setting and a thermometer isn't going to react fast enough to really tell you where your at at an exact moment. If your set at 400 theroreticaly half the time your baking your under 400 degrees. my electric kitchen range set at 400 and measured with my digital grill temp probe which is much faster reacting then a kictchen thermometer will run from about 370-390. to keep the temp at a minimum of 400 degrees I have to set it on at least 430. Its my old range that's out in the barn and I do pc in the winter and when it gets cold I have to run even higher temps to maintain at least 400. Last winter I tested it on a 10 degree day and I had to set it to 450 to keep it that way. I don't know why. If nothing else it sure would take longer to recover from it dropping to the cut in temp. I would have guessed no matter what the temp is the electric high low switch would kick on at the same temp and kick off at the same temp but the cold did effect it. Has anyone that uses a full sized electric stove ever thought about trying it on broil instead of bake. It would see that that way it would transfer heat better to the bullets.

[Rick Hodges]

Lloyd I have a convection toaster oven and use a Taylor oven thermometer to set the temp. I have to set the dial at almost 450* to get 400 on the thermometer. I preheat the oven then put the bullets in and watch for flow out and set timer for 20 minutes. The oven thermometer cycles between 350-405* during that time and I have no problem with smokes powder curing. It probably averages around 375*

[cwlongshot]

Im running two ovens. (Both cheapos,)One is set to 345 and the other 375. Both are lined at bottom with with lava rock and tested to be consistently, just under 400. On these if I set even a lil higher, higher they jump past 450. So I run them at 380-395. I have t had or seen issues testing as everyone has suggested.
The lava rock goes a long way on these cheap ovens to maintain consistent even temp within the oven. My baskets are easily 20% smaller then inner dimensions so not near the outside walls of the oven any how. I also only bake single even layers and avoid over filling a basket if im baking big 44/45/50’s. Conversely, when baking say, lil 22’s I make sure the tray is full. I want the mass as close to same as I can. Again in a effort to consistently bake my boolets.

CW

[Willbird]

I used my Igrill to check mine, it is an Oster convection model from MaoMart. It cycles between 400 and 410...the probes on my older Igrill wimp out about 405 but you can see the curve if you graph the readings in Excel.

The stuff on the left side is adjusting up in temperature then waiting for it to stabilize.



I bought my Igrill when they were fairly expensive, but the Weber iGrill Mini (7202) is only $29 amazon now, it is a REALLY useful tool, and if there were worries about probe contamination extra probes are not expensive. The new ones now go to 716F. One can export a log of a probe as a .csv file then import into excel (I use the corel open office free alternative). Looks like they work with android now too, so an inexpensive android tablet might work great, kindle fire, etc, if one does not have a smart phone.

Bill

[Lloyd Smale]

I used my Igrill to check mine, it is an Oster convection model from MaoMart. It cycles between 400 and 410...the probes on my older Igrill wimp out about 405 but you can see the curve if you graph the readings in Excel.

The stuff on the left side is adjusting up in temperature then waiting for it to stabilize.



I bought my Igrill when they were fairly expensive, but the Weber iGrill Mini (7202) is only $29 amazon now, it is a REALLY useful tool, and if there were worries about probe contamination extra probes are not expensive. The new ones now go to 716F. One can export a log of a probe as a .csv file then import into excel (I use the corel open office free alternative). Looks like they work with android now too, so an inexpensive android tablet might work great, kindle fire, etc, if one does not have a smart phone.

Bill

that's a very consistant set up

[Dragonheart]

do you guys that set your oven at say 400 or 410 and check it with a thermometer and adjust to the point the thermometer reads 400 take into account an oven cycles. It has a low cut in and high cutout setting and a thermometer isn't going to react fast enough to really tell you where your at at an exact moment. If your set at 400 theroreticaly half the time your baking your under 400 degrees. my electric kitchen range set at 400 and measured with my digital grill temp probe which is much faster reacting then a kictchen thermometer will run from about 370-390. to keep the temp at a minimum of 400 degrees I have to set it on at least 430. Its my old range that's out in the barn and I do pc in the winter and when it gets cold I have to run even higher temps to maintain at least 400. Last winter I tested it on a 10 degree day and I had to set it to 450 to keep it that way. I don't know why. If nothing else it sure would take longer to recover from it dropping to the cut in temp. I would have guessed no matter what the temp is the electric high low switch would kick on at the same temp and kick off at the same temp but the cold did effect it. Has anyone that uses a full sized electric stove ever thought about trying it on broil instead of bake. It would see that that way it would transfer heat better to the bullets.

LLoyd, you have hit on the major problem that this whole post is about and that is the actual curing time/temperature your bullets are exposed to. If your oven won't go to the proper temp or hold that temperature within reason then are you "Baking you your PC Long Enough". Oven thermostats are notoriously inaccurate and need to be set and monitored with a good fast reading thermometer. A PID is a solution for a thermostat that has excessive variation. If the oven insulation is really poor or there is excessive air leakage and it will not hold the temp then you should decide if this oven is worth fooling with.

[Willbird]

that's a very consistant set up

I was pretty amazed really, there were two probes in there, one naked and one shoved into a ball of tinfoil and both were quite consistent.

[Willbird]

LLoyd, you have hit on the major problem that this whole post is about and that is the actual curing time/temperature your bullets are exposed to. If your oven won't go to the pro

per temp or hold that temperature within reason then are you "Baking you your PC Long Enough". Oven thermostats are notoriously inaccurate and need to be set and monitored with a good fast reading thermometer. A PID is a solution for a thermostat that has excessive variation. If the oven insulation is really poor or there is excessive air leakage and it will not hold the temp then you should decide if this oven is worth fooling with.

The other thing that showed up in the LASC article on heat treating bullets was how much more effective a convection oven was even with a one hour soak time. It points to bullet temperature not stabilizing yet at 1 hour in a non convection oven.

[Dragonheart]

The other thing that showed up in the LASC article on heat treating bullets was how much more effective a convection oven was even with a one hour soak time. It points to bullet temperature not stabilizing yet at 1 hour in a non convection oven.

Placing a thermoprobe in a ball of foil is an interesting idea, but casting one in a bullet was very easy and it lays in on a tray with no problem.

But the length of time for the substrate to come to temperature in a convection oven is just another reason why following the "20 minute time after powder flow" cure schedule is a bad idea. Prismatic Powder whose technicians I have spoken with on several occasions and a retired Phd polymer chemist all have told me the same thing, curing time starts when the substrate reaches the required temperature. This formula works whether I cook 5 bullets of 5 thousand. But now with a thermocouple I can lay in the tray to monitor the substrate temp takes the guesswork out of it for me.

[Willbird]

Yes I plan on making one of my own. BBQ folks sometimes do the ball of foil trick, that is where I picked up the idea.

Bill

[Conditor22]

Im running two ovens. (Both cheapos,)One is set to 345 and the other 375. Both are lined the bottom with lava rock and tested to be consistently, just under 400. On these, if I set even a little higher, higher they jump past 450. So I run them at 380-395. I haven't had or seen issues testing as everyone has suggested.
The lava rock goes a long way on these cheap ovens to maintain consistent even temp within the oven. My baskets are easily 20% smaller than inner dimensions so not near the outside walls of the oven anyhow. I also only bake single even layers and avoid overfilling a basket if I'm baking big 44/45/50’s. Conversely, when baking say, little 22’s I make sure the tray is full. I want the mass as close to the same as I can. Again in an effort to consistently bake my boolits.

CW

CW has a good point here. A good heat sink (material on the bottom of your oven that retains heat) goes a long way on stabilizing temperatures and helping the oven return to 400° faster after opening the door.

CW used lava rock, I use ceramic BBQ briquettes, others use fire brick. You need to make sure the material you use does not interfere with the heating elements or the convection fan.

"So how can you cure powder with heat? The short answer is “however you want”. Powder doesn’t care how you heat it as long as the surface gets to the temperature that is necessary to cure the powder and stays there for the cure time necessary."

https://www.eastwood.com/hotcoat-pow...-articles.html

Eastwood States: when the surface of the part reaches 400° (checked with an IR thermometer)(or "once the powder flows out and appears to be smooth" {11 min into the video}), bake/cure for 20 min

What this tells me (and I always suspected) is you bake your boolits for 20 min (Eastwood) or XX minutes after the PC flows seeing the PC flowing indicates that the surface of the boolits' have reached the proper temperature.

According to Eastwood: Don't touch part/boolit with bare hands

Dang, there sweeping up enough powder from the floor to do tons of boolits {12 min into the video}

[Lloyd Smale]

I can believe that because your oven senses temp in one location and a conventional oven is not the same temp everywhere in it. The bottom gets hot because the burner is there. the top gets hot because heat rizes the center isn't consistant. A convection oven actually circulates the air everywhere in the oven is much more likely to be the same temp everywhere. What I found in my old kitchen range is that temps vaired ALOT depending on where I put the probe. As much as 40 degrees. Then add in the kick in and kick out temps set by the thermostat and you could easily be undercooking bullets. Now put that same oven in zero temps (like I was baking in) and id bet that difference doubles.

The other thing that showed up in the LASC article on heat treating bullets was how much more effective a convection oven was even with a one hour soak time. It points to bullet temperature not stabilizing yet at 1 hour in a non convection oven.