Effect of too-high temp on both coating and lead?

[BHuij]

I picked up a thermometer so I could test my dedicated toaster oven that only gets used for PCing boolits. I have been setting it to 400F and popping boolits in for 20 minutes, then letting them air cool.

Turns out when I set the dial to 400F, my thermometer was showing about 500F. A few questions:

1. Could this be negatively affecting the toughness of my powder coat? I'm using HF red, and it seems relatively easy to strip off the PC and get back to plain lead. Have never tried the hammer test, but I suspect my boolits would fail spectacularly.

2. Could this be annealing my lead and softening it? I am not noticing slumping or puddles, but 500F for 20 minutes seems like a really sketchy area for air-cooled WW.

3. Would my boolit hardness (or PC hardness) benefit from quenching the boolits in ice water immediately after removing from the oven?

Yesterday I found where the sweet spot was on my temperature dial to actually get the oven to exactly 400F. I tried PCing some boolits using that corrected temperature, and will be trying them out tomorrow. The coating looks about the same though as it always has, thus far.

[farmerjim]

Are you sure the thermometer is correct? It can be off as much as the oven.

[BHuij]

Heh, I'm really not sure. But it seems like a device created for the sole purpose measuring the temperature inside an oven is more likely to be accurate than a $5 toaster oven that can melt cheese and toast bread just as well at 400F as compared to 500F.

[#40Fan]

Thanks for that last post. Still chuckling.

Are you using anything to clean the bullets prior to powder coating?

[farmerjim]

Still not the best but Test it in your household oven at 400.

[BHuij]

Further testing does seem like a good idea to confirm the accuracy of my thermometer.

That being said, let's proceed under the assumption that I really have been baking my boolits at 500F for months. Could this be contributing to my leading problems?

[farmerjim]

If you water dropped the boolits when cast, they are annealed some even at 400.
As you air cooled them, then there is no additional softening. I don't think that you need 20 minutes. I preheat to 425, then drop to 400 after loading, and heat for 15 minutes. The outside of my 9mm 125 grain boolits reach 400 at 6 minutes in the oven as indicated with 400 deg tempilaq. Larger boolits would take slightly longer, also the loading of your oven would also make the recovery time longer. I have forgotten to lower the thermostat on my oven when loading and baked 15 min at 450 with no problems.
I do not water drop PC'ed, but I believe I have read where some do.
I only used HF red one time and changed to Smokes powder. It works much better in high humidity Louisiana. If you are striping off the PC when sizing, it could be a rough die. Polishing will usually cure this. Do try the smash test, It will confirm that the PC is cured and adhering or not.

Did you size the boolits before PC'ing? What sizer are you using?

[BHuij]

Mine are air cooled, so oven may not be having any effect.

I have some Smoke's clear coming my way as soon as he gets it back in stock. I'm in Utah, so probably the opposite of high humidity, but I am still hoping Smoke's powder works a bit better than HF Red. I seem to have a really hard time getting even coverage with HF Red. The PC isn't stripping off when sizing, but it seems to strip off really easily when in contact with metal. For example, yesterday I loaded up some 105gr SWCs in my 9mm casings so I could test them out in my M&P and see if they would chamber and feed correctly. They were chambering and feeding well, but when I picked the rounds up off the floor (I just kept racking the slide to make sure the next round chambered), most of them had a ding on them from scraping against the feed ramp up to the breech. The ding showed exposed lead, in that tiny area, the PC had been dinged off.

I do not size before PCing, I size after, using a Lee push-through .358" sizer.

[farmerjim]

I could not get .357 sized boolits to chamber in my M&P 9. I had to send it to DougGuy to have it throated. He also crowned it and pollished the feed ramp. It shoots great now. The parts of the boolits that I have recovered from my berm show the PC still attached except where the lead is shaved off. If the ding is on the SWC nose where it does not contact the lands it should be no problem. I have had the nose on 308 bore riders get a bit of the Hi-Tek shaved off without causing leading. ( I use Hi-Tek coating on rifle bore rider boolits because it is much thinner than PC and the PC on the nose is too thick to chamber it. Hi-Tek is great on pistol boolits, but it is a bit tricky to get it right. PC is easier to learn, but slower.
Smokes powders work much better than HF for most people, but works fine for others (not me).

[jcren]

If in doubt, check the thermometer in boiling water. Water boils at about 212 degrees.

[BHuij]

Mine chambers just fine even with .358s; my barrel slugged at .357. Still getting that leading though, so I'm tearing apart every possible reason why that might be, and issues with my PC were next on the list.

[Walter Laich]

If in doubt, check the thermometer in boiling water. Water boils at about 212 degrees.

Gosh, mine boils at 100°C

maybe I've got defective water

[popper]

If passes the smash test probably ok. I overheated some with smokes red yesterday base started to slump and PC on nose started to peal off. IMHO the poly starts to shrink when overheated. Never had the problem with epoxy.

[Minerat]

100 C it freezes a 0 C then right? Gots to be defective!

[res45]

Mine chambers just fine even with .358s; my barrel slugged at .357. Still getting that leading though, so I'm tearing apart every possible reason why that might be, and issues with my PC were next on the list.

What alloy are you using? I'm run a NOE 124 gr. TC bullet sized to .357 in my CANIK TP9SA cast with 50/50 PB/WW and powder coating with Smokes Yellow/Green and it leaves my bore nice and clean. It it possible that you might be swagin you bullet down when applying the taper crimp and have you pulled a bullet and measured it?

[bangerjim]

If in doubt, check the thermometer in boiling water. Water boils at about 212 degrees.

Depends on your altitude! 212 at sea level.

[Smoke4320]

Gosh, mine boils at 100°C

maybe I've got defective water

maybe you should but American water and not that metric swill

[bluejay75]

Heh, I'm really not sure. But it seems like a device created for the sole purpose measuring the temperature inside an oven is more likely to be accurate than a $5 toaster oven that can melt cheese and toast bread just as well at 400F as compared to 500F.

Now thats funny right there...^^^^^^^^^^

I usually cook my powder coat in a pile and run my oven as hot as it will go until I am satisfied that flowout has occurred throughout the pile. Then I turn it down to 400 for 15 minutes. Results in less stuck bullets and almost a glass like smoothness on the coat.

[earlmck]

Obviously you were running way too hot, and since you seem to be having leading issues I'd guess your powder coat is failing due to the "too hot" deal. But if you were really getting to 500 degrees in the oven you would see at least some of the boolits slumping, especially those nearest the heating elements.

[Lloyd Smale]

I wouldn't think youd hurt a thing unless your bullets slumped. I do all mine at 450f for at least 20 minutes and have never had a problem. Only powders ive used came from smoke so I don't know about any other powders.