Most people ARE NOT baking PC long enough

GRMPS

Active Member
It seems most people ARE NOT baking PC long enough!!!!
This will cause an incomplete cure which allows gunpowder to affect the PC surface of a bullet

the following has been my experience (note the bake time is 20 min after, not 10 total)
I guess the bake time is relevant to how/when you start gauging it

https://www.powderbuythepound.com/super-durable-wet-black.html
  • Cure Schedule = 400f/10 Min at Part Metal Temperature
http://www.cardinalpaint.com/assets/Uploads/WH09-T013-TDS.pdf
Cardinal paint CURE SCHEDULE: (METAL TEMPERATURE) 10 MINUTES @ 400 DEGREES F.


https://www.eastwood.com/hotcoat-powder-ford-light-blue.html
SPECIFICATIONS

Color: Ford Light Blue
Gloss Level: Gloss
Cure Temperature: 400 Degrees
Cure Time: 20 Minutes after flowout
Powder Type: Polyester TGIC

Thanks goes to IAN who brought the "bake time starts after the surface temperature reaches X degrees to my attention, I always went by Eastwood's directions and never had a problem.
 

fiver

Well-Known Member
yes.
I didn't read any directions when I got my first bunch of powder [mainly because I didn't get any]
but waiting for the powder to turn 'wet' seemed like the right time to start the timer, not when I slid the tray in the oven.
 

JWFilips

Well-Known Member
May be overkill but once my Pre-heated oven comes up to 400 deg and I get a flow I set the timer for 30 minutes!
 

GRMPS

Active Member
One way to help speed up the process a little is to cover the bottom of your oven with something that retains heat, this helps the oven recover much faster after the door has been opened. I use ceramic BBQ briquettes, others use firebrick, rock, pieces of metal ....
 

Brad

Administrator
Staff member
This is very helpful information.
Within reason is there any harm in over baking? Say I have a pre heated oven and do like Jim and set a timer for 30 min when I put in the bullets. If that means 5 min longer than needed is there a downside?
 

GRMPS

Active Member
I haven't seen one, but then I haven't baked for more than 30 min past the PC melting.
 

Gary

SE Kansas
I've had the PC (especially a yellow color turn to a color in between yellow and brown when I cooked over 20 min @ 400.
 

Ian

Well-Known Member
I've pushed the poly TGIC powders (400F for ten minutes AT PART METAL TEMPERATURE) to 415F for 50 minutes starting from a preheated oven and had no problem with the coating deteriorating, even after going straight into a bucket of water.

Along with under-curing or thinking that seeing flow means the surface is up to full temperature, a commonly misunderstood thing about TGIC is that cross-linking is a function of time and temperature. You can get by with more heat and less cure time, or vice-versa. This is handy for coating things you don't want to get up to 400. There are also low-temp formulas as well.
 

GRMPS

Active Member
This Test of your baked boolits will give you the answer to if you are baking them long enough.

Set a baked boolit in a small container covered with the gunpowder you will be using and see if there is a reaction in a couple days and a week
.

The X degrees they are waiting for to start timing is not the oven temp but the temperature of the boolits

In the end, only You can decide what you want to run through your gun.
I can only show you what the manufacturers recommend for their product.
Like others have said, when it comes to my guns, I ALWAYS proceed on the side of safety.



https://www.prismaticpowders.com/sho...3/gloss-black#
CURE TIME & TEMP: 10 min. @ 400°F
As always, the cure time starts when the substrate reaches temperature


https://www.thepowdercoatstore.com/c...ck-powder-coat
Polyester
Cure Schedule: 15 Minutes at 375F Degrees (Part Metal Temperature)


https://www.tcipowder.com/media/1086...r_coatings.pdf
Cure Schedule: 12 Minutes@ 375°F
Metal Temperature Minutes@ °F


http://www.columbiacoatings.com/stor...tructions.aspx
POWDER PAINTING

Be sure gun is properly changed to the color desired before coating.
Check that you have the proper air pressure set (Refer to your powder gun manual). If using our Hyper Smooth or Kool Koat Powder Systems, we recommend 60 psi to the control box. We highly recommend using an air regulator on the gun and not relying on a compressor to regulate the air because the actual pressure that builds up in the air hose is more than the gun requires and can cause bursing of powder at the end of the gun.
Make sure the part you are going to powder coat is properly grounded to a true earth ground.
Preheating parts at 375-400F for 10-25 minutes is highly recommended to help outgas parts and kill any material such as oils that could have been missed when cleaning parts.
Cool for 3-5 minutes or when the material reaches 175F. This will help with Faraday Cage Effect in the areas where powder has a hard time adhering such as cracks and creases in your parts plus shooting warm uses less powder. It is not required with our Hyper Smooth and Kool Koat Gun Systems but will help with other gun systems.

CURING
Light Parts: 385F for 20-25 minutes (ie. Pulleys, brackets and other small parts)
Heavy Parts: 385-400F for 25-30 minutes (ie. Wheels, intakes, manifolds) Heavier part=higher temperature
2. Multiple Coats

Chrome/Silver base coat with a translucent and/or clear top coat
Satin White base coat with Red Fluorescent
Primer base coat
Dormant base coat with a clear top coat
Solid Colors: Partial cure for 5-10 minutes.
Metallics: Full cure at 385-400F for 25-30 minutes. Let parts cool down to less than 100F before adding a top coat.


https://www.propowdersupply.com/product/mirror-blue/
Description
CURE SCHEDULE IS 10 MIN AT 400F *PART METAL TEMPERATURE*

INTERIOR OR EXTERIOR POLYESTER TGIC WEATHER RESISTANT POWDER COATING

95% GLOSS LEVEL WITH 60 DEGREE METER * RECOMMENDED MIL THICKNESS – 1.2 – 1.8 MILS *
 

BHuij

Active Member
This is very helpful information.
Within reason is there any harm in over baking? Say I have a pre heated oven and do like Jim and set a timer for 30 min when I put in the bullets. If that means 5 min longer than needed is there a downside?
Doesn't seem like it from my experience. I'm using Smoke's Clear PC, and I have traditionally done 20 minutes in a pre-heated oven at 400 deg F from the time I put the tray of bullets in. Since I start seeing powder melting within the first about 90 seconds, I'm probably "officially" doing an 18-minute bake.

I have then proceeded to throw the already cured PC'd bullets back into the oven for as long as 2 hours at 450 for heat treating purposes, followed by an immediate cold water quench. I've done this with 9mm, 30 cal, and 22 cal bullets. The powder coat gets a little bit less transparent, but appears to be no less durable than it ever was (passes the smash test, does not lead any of my barrels). And I've achieved BHNs with my 22 cal bullets up to 35 using straight COWW.
 
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Ian

Well-Known Member
I'm probably "officially" doing an 18-minute bake.
"Probably" is still a guess. Powder flows at considerably less than cure temperature, so the bullets are still warming. The other thing to note is good cure all the way through the paint happens only once the PART surface reaches curing temperature, not the surface of the paint. Once you see it flowing, I'd add a good triple that amount of time before "assuming" the bullet surface is at cure temperature. If you run a contact probe into the oven, hose-clamped to an uncoated bullet, it will give you a better idea of actual bullet temperature (less the insulating effect of the powder on the other bullets and not considering temperature variances throughout the oven).
 

fiver

Well-Known Member
I'm beginning to wonder if a new cooking procedure wouldn't be a benefit to the process.
something like holding the tray at 350-F for maybe 20 minutes then bumping the temp up to 400 and starting the 20 minute timer when the powder starts to flow [wet] instead of shooting straight for the 400-F zone.
 

GRMPS

Active Member
I have a hard time straying from manufacturers specs. this is their business, livelihood. They have spent $$$ and time researching the best method for there PC. Happy repeat customers mean more sales. I'm not an industrial chemist, who am I to argue with them. Plus, I care enough about my firearms and bullet quality to do things the way I see best. What is a couple more minutes to ensure the PC is cured completely?
 

BHuij

Active Member
I’m getting good results with a “20 minutes after I put it in the oven” approach, but I don’t really see any disadvantage to giving it 30 or 40 minutes, to be safe, especially since there doesn’t appear to be any disadvantage to overbaking.
 

Rick H

Member
I do 20minutes at 400 after flow out....my convection oven varies from about 375-400 while it heat cycles. I use a mixture of HF red and Smokes powder and have tested for powder reaction. I have never got any reaction to powder like others have described. Perhaps the longer cook time is the reason? I have no clue.
 
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Ian

Well-Known Member
I have never got any reaction to powder like others have described. Perhaps the longer cook time is the reason? I have no clue.
I think that may be a big part of it. Blending HF epoxy and Smoke's poly powder may be another.
 

Brad

Administrator
Staff member
For those of you who ordered from Smoke what kind of time frame did it take to get the order?