Pre-heating boolits

[Desertbuck]

At what temperature do you guys think powder coating just start to stick? I've been playing with Elvis ammo method by heating up the boolits to the point the powder coating just starts to stick. He said it's 150 degrees at 4 minutes I'm thinking it's closer to 200 and it doesn't matter if its 4 minutes or not. The boolits juts need to be at a precise temperature. I have to say it shows a lot of promise! The big trick is as soon as you dump them into the powder coating start shaking and don't stop until they cooled down. And as he promised it will only take half the time. I'm headed out to go find a better oven thermometer. But anyone who may be able to point me in the right direction to starting temperatures would be very much appreciated. The powder is Harbor Freight red by the way.

[bangerjim]

I have 100% success doing it the right way......plain old BBDT. No cleaning or preheating needed on the many thousands I have done. I get ~95% ESPC quality with BBDT.

Preheating to get the power to melt could/will cause clumps and very uneven coatings! You have absolutely ZERO control over the thickness. At least with BBDT and ESPC, you have a limit as how thick the coats go on....and they are always perfectly even for me.

It takes a WHOLE lot longer for a bunch of boolits in a tub to cool down than it does to do BBDT the right way.

Do what you think you need to do.

banger

[Dragonheart]

If you live in a desert environment preheating is not necessary, but if you have to fight with sometimes 90% humidity of the Gulf Coast preheating makes the difference between coating and not.

At 250 degrees you are going to have a sticky ball of ruined bulets. 150-200 degrees works getting more build up at the higher end. I dump my preheated bullets into a running electric self made tumbler fit for purpose, so having to shake a tub is not something I have to deal with. You will find preheating causes the powder to bond almost immediately, so the coating is no where near as fragile as is with a non-heated tumbling or especially a non-heated spray coating.

Some powders just do not cover with a normal shake & bake single coat; preheating will allow these powders to lay on a heaver coat and give you a nice single coat coverage. Harbor Freight Red is one of those powders that Banger has no problems with, but here if I don't preheat I have to double coat. However if you have a powder that coats very well then preheating can give you a much thicker build up than you may want, which can make sizing difficult or impossible. Hate to be vague but sometimes you just have to play around with it and find what works best for you.

When I am coating other objects I preheat the object to 400 degrees the spray coat immediately. At that temp the powder bond and flows on contact, so I can see what I am going to get and control the coverage. Then I cure the normal way after the object has cooled enough to handle.

[Desertbuck]

Okay I just tried it and you're right all I ended up with a mess. It worked ok for 223 boolits. But not any bigger. Oh well. I will just stick with BBDT

[Dragonheart]

Okay I just tried it and you're right all I ended up with a mess. It worked ok for 223 boolits. But not any bigger. Oh well. I will just stick with BBDT

Bullet size is not the problem as I do everything up to 230 grains. You just need to confirm your oven temp with a good quick reading glass thermometer, like the Taylor Oven Guide, to make sure the pan of bullets doesn't go over 200 degrees 150-175 range works well.

[Phantom30]

Tried Elvis Ammo's technique several times. The boolit preheat temperature is a straight 140 degrees F for five minutes, he recommends less than 150F. Dump, shake fast, pour out on rabbit wire tray and bake for another 15 minutes. Other than the wire tray issues, the problem with it is that cheap toaster ovens do not hold low temperatures very well, their control thermostats behave in a bang bang full on full off, so the temperature profile is all over the place. My results have been hit and miss. My preferred method, especially for larger HP boolits is ESPC on a Spike board and bake for 20 minutes. Coatings are smooth consistent and resultant accuracy of the rounds is tight.

[Dragonheart]

My preferred method, especially for larger HP boolits is ESPC on a Spike board and bake for 20 minutes. Coatings are smooth consistent and resultant accuracy of the rounds is tight.

Agreed, the only reason I preheat bullets is when the humidity is so high even spraying is a problem and tumbling gives a spotty coating.

[Lagamor]

I use the Elvis method when humidity is high. I just put my next batch on top of my toaster oven to preheat and that works fine for me.
Dont have a thermometer on top, but the inside hold 400 degrees well.

[Desertbuck]

Thanks for the fast and knowledgeable replies. And as you guys have stated it is just too hard to hold a precise temperature with cheap toaster ovens. My oven thermometer proved that to me. However my results with BBDT have always been good. The preheating trick is just going to be a hit and miss thing. I would just rather spend an extra 15 minutes doing it right then doing guesswork is the conclusion I came to. I mean it's not really hard to shake for 2 to 3 minutes then dump the entire contents of your container BB's and all into a pie pan with wax paper pick up the bullets and place them neatly on a cooking tray and simply put BB's and powder back in the container and do another batch. While the first is cooking.
No wasted Boolits!

[VeryOldGuy]

Your temperature and time will vary based on the bullet weight, quantity, and prior lead temperature before inserting them into your oven.

[RP]

Yes there has been methods that work most of the time but tinkering is in our nature sometimes we find a better way which will work for you but not the next guy. If we stuck to what others told us was the only way I think we would be still busting skulls with rocks and poking critters with sticks.

[JWT]

I have not PC'ed any boolits but I have been involved with paint systems that have PC'ed a few million cars and trucks. Heating a body before powder application will result in unacceptable film build variation. In the automotive world the charged powder is applied to a grounded body in a rigidly climate controlled environment. This results in a predictable film build based on the charge voltage, humidity, downdraft, fan air, and body contour.

When PC'ing the boolits the beads and container provide the static charge. The film build is fairly uniform due to the limitations on generating the static and the insulating properties of the PC on the boolit. Heating the boolit serves to drive off humidity (same concept as a Goldenrod heater in your safe) and allow the generation of a charge. The temperature of the boolit, beads, container, and powder must remain well below the point that the PC starts to soften. I would suspect heating the entire mass (lead, powder, beads, and container) to around 100 to 105 and leaving the lid open for a minute or two to allow for the moisture to escape would allow for powder coating even in high humidity.

[SSGOldfart]

I preheated jig heads for powder coating,by holding over a gas flame be sure your powder is really stirred up well,3to4 seconds works for me,then oven bake,I built a air powered paint bath for coating jigs much faster,but with bullets Ijust do shake and bake method.quick dip just doesn't look so good when you're a few thousand behind