PC powder questions

fiver

Well-Known Member
here is another tip.
watch your bullets in the oven.
the powder has a temp [350-375] where it goes into what I call the ''wet'' stage.
this is where the powder is flowing around and opening up the strands and working it's cross link magic.
after some time in the wet stage, then take the oven temp up to the 400-F curing stage.
it takes me almost an hour to bake a batch of bullets because I heat and hold the bullets in 3 stages for about 15-20 minutes each stage.
my 400 stage is actually 22 minutes long because it doesn't start until the heat cycle in the oven has completed.
 

Tomme boy

Active Member
@fiver have you checked to see if the bullets are heat treated by baking so long? Or is the temp too low? I water drop mine right out of the oven. They seem to harden a little bit over a weeks time. I try to size the same night if they are dry. If I don't you can definitely tell they are harder after a weeks time.
 

fiver

Well-Known Member
i haven't but I would assume the hour long soak time and then the water bath would have an effect on the hardness.
a short 20 minute cook won't beyong the smallest amount.
the longer soak will allow the alloy to move and readjust, but not quite like a full hour at 400, I'm probably seeing the equivalent of 350-375 and a water quench.
I still have to rely on the bullets to fill out the throat like I would with straight from the mold quenching.
but that's my method, which is a little bit different than the normal what everyone else does [you know as usual]
 

CWLONGSHOT

Well-Known Member
Generally speaking I only quench my cast for speciality bullets. (Our of the Mold)
But I ALWAYS quench out of the powder coat oven.
THERE IS NO BETTER WAY to soften a bullet than bathe it in 400 degrees for a while and let it air cool!!!

Many writings are on this over on CB and generally accepted that hardest is quenched twice.Straight out of the mold and then again outta the PC oven.
Softest was from neither. ;)

But I find my PC is better too when quenched. It separates easier. Powders/colors react different to baking. Adjustments in time and temp can make favorable results.
 

JWFilips

Well-Known Member
Because I'm not real steady handed any more I do not carry my full trays to the pre heated oven anymore! (Just can't do it with out a major fall over)
So I now start with a cold oven and place the bullets on the silicon mat that is on my tray, that is already in the oven, with tweezers!
Once loaded I close it up and start the PID controls after about 15 minutes the PID is holding the temp at 400!.... the I let it preheat for 15 more minutes and then add 20 minutes for the full cure. That is what works for me
I mostly use Smokes Clear but also use Eastwood Ford Blue and recently ( for my wife) Smokes Purple.
I can flatten a bullet into a dime and the coating doesn't fail!
 

fiver

Well-Known Member
i have swaged 32 cal bullets up to 35 caliber and kept the powder in place.
you can see the clear coat come to the top when you do that.
 

DHD

Member
Besides the colors and performance of PC, one of the neat things about it is that so many techniques work. I still use BB's, stand my bullets up (gotta move slow putting them in the oven), and just turn my timer to 30 minutes for the first batch. If doing more than one pan full, the next pan will go in the hot oven for about 20 minutes (verified with oven thermometer at 400°).

I have a lot of Smoke's powder but lately I been using Prismatic Powder in various high gloss colors. What a shine that high gloss has!

I forgot to add that it's a proven fact that high gloss bullets are more accurate and faster than matte bullets. You don't even need to shoot them for them to be more accurate. All kidding aside, the biggest problem with having a lot of colors is that you'll use those colors. It might be a sickness....
 
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Brad

Administrator
Staff member
I just bake for 30 min and call it good. I figure that gives plenty of time for powder to begin doing it’s thing and for the bullets to come up to temp.
On 250 gr and up I will even go 35 min.

Everything I read shows there is little danger in over baking
 

358156 hp

Well-Known Member
I've managed to "yellow" Smokes clear with an apparent overbake. I preheated the oven to 420, then put the bullet tray in and started the timer for 30 minutes when the temp returned to 400*. My bullet tray is 3/16 steel plate, and it makes one hell of a heat-sink. The powder coat seems fine, just slightly yellowed. I managed to do the same with Carolina Blue. It ended up with a slight yellow tinge. And my oven is controlled by my PID with the probe tip at the same height as the bullet tray.
 

Ian

Notorious member
I use thin steel plates too, thinking that induction will equalize the temperature when the tray is heavily laden and some bullets are closer to the convection fan than others. It must work because the coating changes sheen on all the bullets at the same time.

Having checked actual bullet temperature with a contact probe, my oven gets them to 400⁰ in about 5-8 minutes depending on size. The powder starts to flow at around 300-325. So I go about 22 minutes from a warm oven and 23-34 from a cold one. YMMV, not all ovens are created equal and not all of us are loading our trays or baskets the same.

Regarding the over-bake, I did a little heat-treating experiment a while back and had to oush 420⁰ for a minimum of 45 minutes in order to affect a significant change in quenched hardness, and even then I only got about halfway between air cooled (aged) and maximum heat treat of the alloy. The sky blue 100% gloss Polyester TGIC powder seemed unaffected by the extra time and temperature, and I did shoot them at over 2900 fps afterward with good accuracy and no fouling.
 
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JWFilips

Well-Known Member
One thing you have to remember: which I found out the hard way.... My first batches were 50 bullets each batch and I had my good casting thermometer in the oven & I waited till it hit 400 F My PID was set at set at 207C all well and good for a few months ,. Then when I was running out of bullets I stared doubling up the tray to upwards of 100 bullets per bake ! Guess what....The PID setting of 207 C was not good any more ! The only way I could he the manual thermometer up to 400 F was to up the PID setting to 224 C! What a PITA! Good thing I slipped the Casting thermometer into the oven!
Then when I did a batch of 50 bullets I had to drop it back to 207 C! It is not the PID's fault it has to do with the oven elements....if you overwhem them with too much mass to heat at any given time you PID setting will never get it up high enough! so be aware of that!
That is why I always place a casting thermometer in the oven when I PC coat!
 

Ian

Notorious member
Yep, that's why saying we do x temperature for x minutes is meaningless to anyone else. We have to verify our actual setups ourselves. The one constant is the powder instructions which typically will be 400⁰F for ten minutes once the parts being coated have actually reached full cure temperature. It is up to us to make that happen with our equipment and verify it every time we change something like the total thermal mass of the bullets.
 

Brad

Administrator
Staff member
My PID is set at 410° but with a heavy tray of bullets the oven seems to max out at 390-395.
 

358156 hp

Well-Known Member
I use thin steel plates too, thinking that induction will equalize the temperature when the tray is heavily laden and some bullets are closer to the convection fan than others. It must work because the coating changes sheen on all the bullets at the same time.
I've noticed this too. IIRC, the bullets gloss over starting at the top and working their way down rather quickly.

I think I tried to see how hot my oven would get, and I got it up to around 475 or so before I chickened out. This was with a tray of 9mm bullets in for heat-treating, and I must have done the right thing because I did find some slumped bases afterward. Right in line with the two bottom heating elements. I guess the radiant heat did them in, not the ambient heat.