Most people ARE NOT baking PC long enough

[popper]

curing time starts when the substrate reaches the required temperature.

PC is somewhat of a thermal insulator so the alloy has to get to proper temp. to get the 'cure' on the alloy surface. Just because the PC flows doesn't not mean it is near cure temp. Adding thermal mass to the oven just means it takes longer for the temp to increase although it does tend to heat more evenly. Just compensates for heat loss when opening the door. Heat is like water, when it leaks you have to replace it.

[Slingin'Lead]

I apologize for not looking closely enough at the pics that have been posted. My recovered boolits look like the ones in Triplebeards post.

[Dragonheart]

I've been using Eastwood powders and baking for 20 minutes in a thermometer verified oven.

Yesterday evening I recovered some boolits from my trap. (Lee 356-120 TC coated with Ford Lite Blue) Lead was showing through on some of the rifling marks on the boolit bases but when I cleaned my pistols after firing them I had no leading so I'm confused about what is going on.

Have you slugged your bore? If your bullets are oversized for your barrel, the the barrel is being forced to move metal and it has to go somewhere. .001+" over actual bore size is enough to seal the bullet. I have found no advantage to oversizing bullets. In my limited testing oversizing degrades accuracy.

I have water trapped slugs for all my firearms that I cast for. Water trapping is easy, once set up one can slug a lot of firearms in an afternoon.

[Conditor22]

Been watching some Eastwood instruction videos this morning, learned a couple of things

1) Eastwood chrome the substrate takes longer to reach 400° and an IR thermometer is required for a correct cure / finish chrome must be baked properly -- bake 20 minute at 400° AFTER the substrate reaches 400°.
2) you can powder coat non-metalic items as long at you can heat the item to 425 and you have a PC spray gun and coat it while it's still hot then bake it the prescribed amount of time.

[prs]

Other than loss of time and electricity, is there any harm in using extended bake times? Say, instead of 20 minutes after flow, can I safely bake for 35 minute bake time without harming the paint quality?

prs

[Conditor22]

prs, yes you can bake powdercoating for an hour at 400° without harming the paint quality?

Some people do this to quench after PC

[bruce drake]

I use Cardinal and Eastwood powders. I preheat the oven to 400 degrees and stick them in. 20 min. later I take them out of the oven and I have never had a failure to cure. I have forgotten to check the time and left them in much longer with no harm done. A little more electricity used doesn't bother me in the least. Gp

Yep. Same process I use for Eastwood powders. The key is to have an accurate oven thermometer to ensure you are up to the temp before you stick them in the oven.

[prs]

prs, yes you can bake powdercoating for an hour at 400° without harming the paint quality?

Some people do this to quench after PC

Thanks. Two full trays of 250g bullets in a convection/toaster oven is a pretty massive load of lead to bring up to temp.

prs

[jimb16]

Depending on the size of the bullets, I allow 3-5 minutes for the lead to approach the correct temp. After that I look thru the window to see if the powder is starting to gloss, indicating that it is starting to "melt". When it reaches that stage, I start the 20 minute "cook" time. I usually end up going a minute or two over. My oven is not very stead on temp as it varies around 20° so I try to keep the temp between 400 and 420. I never have any problem with pc failure.

[Dragonheart]

Depending on the size of the bullets, I allow 3-5 minutes for the lead to approach the correct temp. After that I look thru the window to see if the powder is starting to gloss, indicating that it is starting to "melt". When it reaches that stage, I start the 20 minute "cook" time. I usually end up going a minute or two over. My oven is not very stead on temp as it varies around 20° so I try to keep the temp between 400 and 420. I never have any problem with pc failure.

What you are doing may work for you, but unless you actually monitor the temperature it is just a guess. I can assure you if I used your method I would end up with severely undercured bullets. Count the bullets on a single tray and multiply that by 4 in a single cook for me. It takes time and BTU's to heat a mass and all those are variables. If you really want to control your cook you have to monitor.

[jimb16]

You are baking a lot more at one time than I do. I have a smaller oven that will only take around 100 at a time and heats back up quickly. I do have a thermometer in the oven to monitor the temp. Remember guys, oven size and number of bullets at one time make a difference in your baking time too. You have to allow extra time for larger batches.

[Conditor22]

You canbake a lot of boolits in a smaller oven IF it is a convection oven.

I got tired of checking and monitoring temp so I threw a PID on it. wish I'd done it a lot sooner

[dangitgriff]

Thank you to all who’ve contributed to this thread, very useful info.
R/Griff

[prs]

What comes first? The chicken? The egg? The rooster? That is; in several responses above the bake time is referred to as the "raw time" (Begins when oven door is closed, preheated or not.) Or the set time begins with paint gloss or liquification. Or the time begins when surface of substrate metal is up to target. Or time begins when metal is heated through to target temp. I hope for that last one, but should be at least getting the next to last stage. Pre-heated oven, 400F mean target temp, 15 minutes to heat the bullets to guestimate of target and then 20 to bake the finish. 35 minute total after setting bullets into pre-heated convection toaster/bake oven. I do not know how to measure the deep internal temp of a sample bullet -- any one with an experimental idea? Or, if the sample coated bullet passes the hammer mash test all is good?

prs

[Conditor22]

prs what your doing will cover all the powders I have researched and use with room to spare.

[Socal147]

Think I will try taking my cheapo oven apart to see if I can insulate it better. My powdered coat seem to scrap off too easy. Experiments planned.

[RogerDat]

I read and learn from sixshot. He is the man. I also read and learn and buy powder from Smoke. I preheat my oven to 400 and then I bake for 15min per smoke’s instructions. I have been very happy with the performance of my powder coat. I have not had one problem.

Same here. Pre-heat to 400 and set phone timer for 15 minutes. So probably go a minute or two longer as a get over to remove them after phone time goes off.

Sledge hammer them flat horizontal or vertical and they don't peel. Works for me. I will say I tend to mild to mid power loads. Those going for the top power loads may need to be more rigorous to get comparable success with PC as a lube.

[Frank V]

You guy are getting me to want to try PCing!

[Conditor22]

Same here. Pre-heat to 400 and set phone timer for 15 minutes. So probably go a minute or two longer as a get over to remove them after phone time goes off.

Sledge hammer them flat horizontal or vertical and they don't peel. Works for me. I will say I tend to mild to mid power loads. Those going for the top power loads may need to be more rigorous to get comparable success with PC as a lube.

IF this was the best way to do it, why would ALL the powder coating manufacturers say different?

See what you powder manufacturers say. either in the beginning of this thread or on their website.

THEY ALL SAY

bake for xx minutes at xx degrees AFTER:
(1) the substrate has reached xxx degrees
(2) the powder flows out

IF baking for shorter times at lower temperatures was better, they would state that.

I try to make the best loads I can. I don't want some smokeless powders reacting to under cured PC'd boolits.

[RogerDat]

Titegroup I think is the powder one seen as a culprit for reacting. It has an unusually high nitro content and if bullets are stored with Titegroup powder against bullets some grains seem to settle into the PC on the base after awhile. Turning the box so the bullets are arranged powder down would resolve the issue. Of course many storage systems don't have the bullets in boxes, they are loose in bags or ammo cases so would be difficult to insure no powder to PC contact. I don't recall reports of bullets failing to perform due to this condition but that doesn't mean their are not such reports out there.