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powder coating

Posted: 25 Jan 2020 11:33
by horseman
There are probably quite a few of you out there that do powder coat. I saw a reference to it by RD in a different thread where he had started using it but instead of mucking that topic up figured it was better just to start this one. Soooo, how many are doing this and what "method", spray or shake with air soft or whatever way works for you. I've read very little about it because I just didn't want to start in on another type project with more "stuff" and equipment. Although I haven't cast a single bullet for a few years and the Pot is just sitting in the corner about half full of alloy, I'm starting to run low on a couple calibers and I'm sure the lube in the Star is probably dried hard as concrete. So, may we have a discussion on how's and methods used, types of powder and equipment and what works for you..... +corn

Re: powder coating

Posted: 25 Jan 2020 12:06
by mikld
I like experimenting, so after reading a bit on PCing bullets I gave it a try. My first method was the "shake and bake". I put powder in a Cool Whip tub a tablespoon of powder (HF red) and shook it for a couple minutes. I picked the bullets out and stood them on their base on a piece of aluminum foil and baked them @ 400 degrees for 20 minutes. Success! I did about 500 in various calibers/weight bullets like this and figgered I'd try something different and got an electrostatic sprayer. Had to make up a conductive base to place the bullets on, but no big deal. Same good results but the bases were nekkid (I could have probably found a remedy, but didn't get that far.). One major drawback to spraying; over spray. The powder is very fine, seems to be finer than talc, and gets every where. Outdoors any breeze will blow the powder away from the bullets and indoors some kind of spray booth is necessary. Handling powder can get really messy and soap and water are the easiest way to get it off your hands (wiping with a rag doesn't work well). But PCed bullets do everything they are supposed to do; clean shooting, clean handling, and just as accurate as cast lead. Some have driven their PCed bullets to higher velocities. I haven't don any in a while as I have a bunch already done and waiting. The best place I've found for real life info on PCing and HiTec coating is; http://castboolits.gunloads.com/forumdi ... ternatives

Re: powder coating

Posted: 30 Jan 2020 22:17
by reloader762
This is how I PC my bullets, the method you use may be totally different and give you the results you like and that what matters in the end.

Tools:

Convention toaster oven for curing your bullets.

First thing you want is clean bullets, any contamination on the bullets will cause the powder not to stick. If in question, just give them a quick wash in Acetone and let them dry off before applying the powder coat.


I prefer the convection oven because it heats more evenly. You can pick one up at a resale store on the cheap or just buy a new one for around $30 to $40 depending on what you like. ONLY use the oven for curing powder coated bullets or heat treating bullets from that point on, NEVER use it to cook food in afterward. If the oven is not digital and controlled by an internal PID get yourself an oven baking thermometer Amazon to set your temperature dial as close as possible, I would get one anyway just to double-check the oven as most toaster ovens heat either cooler or hotter than the dial indicates. Set your oven to keep a constant temperature at around 400 degrees, if the temp runs +/- 25 degrees it want hurt anything, but I prefer it to stay as close to 400 degrees as possible with the powders I use, you just don't want it to get too high or too cool.
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Plastic container for tumbling bullets in.

You will need a one or more #5 plastic containers and lids depending on if you want to do more than one color, screw on types are the best but snap on lid types like I use work fine too, just make sure you have a tight seal. I use these two types of #5 container I recycle from home along with multicolor plastic pony beads I get at WallyWorld for $1.50 per pack, or just buy some 25 MM air soft BB's off Amazon, they are large enough that they want stick in my big 45 ACP HP's. The combination has worked well for me to generate lots of static electricity to attract the powder to the bullets. One thing of note is that LOW HUMIDITY is your friend as it will make generating static electricity easy, I like it to be 40% or lower. At times, I've had to coat in the house and take them out to my reloading shed to bake and cure.

#5 container from local restaurants.
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Great Value Yogurt container.
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Pony beads, I use these beads, but others may not find them necessary to achieve their desired results.
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In the small container I place enough beads to fill the bottom about 1" deep, in the larger container I add enough to fill it between 1" and 2" but no more than that. I add about 1/2 TSP of powder to the container with the beads and shake it up for about 30 sec. notice how it already starts to stick to the beads and sides of the container. I always start out with 1 TSP if you need to add more powder to get the desired coat only add another 1/2 TSP to the mix as too much powders will clump on the bullets and you will have to tap it off before placing them on the baking tray. It's easy to add a little more powder to get a fine coating than having too much to start with. Some use no beads at all and get excellent results as well, I just like using the beads as they seem to help generate extra static and create a buffer between the bullets.
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Next I add the bullets. Make sure they are clean of any dirt, oil or lube or any contaminates that might be on your hands as the powder will not stick. I like to wash mine in 100% Acetone if in question, and wear nitrile groves when handling bullets I plan on coating while putting them in the container. I generally add around 50 to 100 bullets to the container depending on caliber and weight, close the lid and shake in all directions for around 30 seconds. Furthermore, I used black air soft BB's that I had with the clear powder coat, and they work great with clear, not so much with some other colors I've used, but the pony beads will work with all colors.
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After about 30 seconds of shaking, I tap the lid to knock any powder off the inside and look at my bullets to see how they are coated. If they pass my inspection, they should look like this or the ones in the white clear coat above.
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Next I take my baking sheet and line it with a piece of Reynolds Parchment Paper, there are cheaper brands of that type of paper, but I think the Reynolds works best, and I get around 3 uses out of a sheet before I toss it, others like silicone baking mats, trays etc., but powder residue tends to build up over time on those, so I just use the paper. I take a pair of long tweezers and place all my bullets base first onto the paper, it takes some time to do it this way, but I can easily have the next tray of bullets ready to cure by the time the first batch is done. Many just dump the bullets into a screen tray, shake off the excess powder dump them and bake, but I like the results I get standing them up individually and the powder flow and migrates evenly with no lumps or flat spots. Then I pop them in a 400 degree preheated oven and set the timer for (20 min. after the powder starts to gloss over.) It takes about five minutes for that process to begin.
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Powders I like to use.

super Durable Clear or Carolina or Signal Blue are all excellent powders to coat with. Smoke will sell you a pound of powder divided into 3 1/3rd lb. bags of his colors if you like, but these are the colors I like and that have worked for me the best with no fuss.
http://castboolits.gunloads.com/showthr ... ng-bullets

Eastwood powders I like.

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


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


https://www.eastwood.com/hotcoat-powder-machine-gray.html


A few notes on cast bullet air cooled or quenched from the mold and how the curing process will anneal the cast lead bullets using an alloy that responds to water quenching or heat treating.

1. If you air cool your bullets when cast then PC them and allow them to air cool again the second time, there is no change in the as cast BHN of the bullet.

2. If you air cool your bullets when cast then PC them and quench them right out of the toaster oven, they will gain a hardness of about 75% over the as cast BHN.

3. If you quench your bullets out of the mold to begin with then PC them and allow them to air cool, they will soften around 50% from the original first quenching BHN.

4. If you quench your bullets out of the mold to begin with then PC them and quench them right out of the toaster oven a second time, you only loose around 15% hardness from the first quenching.

Re: powder coating

Posted: 01 Feb 2020 23:13
by horseman
WOW. Excellent post. Thanks.

Re: powder coating

Posted: 02 Feb 2020 11:31
by larryw
horseman wrote:WOW. Excellent post. Thanks.
+1

Re: powder coating

Posted: 26 Apr 2020 15:31
by Tonerboy1
I too had gone a long time without casting anything. But PC got me back into it. As you see above, there are lots of ways to do it. Shake and bake being the quickest and least expensive way to get your feet wet. I went straight to spray and bake. Definitely spray outside. Some PC's are carcinogens so heads up there. Even shaking should be done outside. If you shake in direct sunlight you will be surprised at the cloud leaking out of your container. A spray gun has a little more setup time and tear down time. But you cant hardly get poor results with a spray gun. Application is the main difference with spraying. The base is not coated when sprayed but neither is the base lubed when you lubrisize on your star. If you go down the road of high pressure you just do the same thing you did before. And if you really want to coat the base just dip the base into the overspray as you load them on your baking tray and BOOM the base is covered. Usually there is enough static still in the bullet and overspray to get a decent coverage. Sprayed bullets look like store bought, and for me shake-n-bake bullets look home-made. I cant seem to get the nice even coat that some people can get when they are banging around in a tub.. They are definitely shootable, but not necessarily showable. I typically save my overspray and save it up to use the shake method when I just want something to shoot.
If you just want to give it a try shake away. Once you see how it works and if it works for you, more than likely you will move to spraying. HF has a workable spray gun for less than $100 when on sale, there are others online that sell inexpensive guns also. Most you will see are the same unit with different brand names on the stickers. Good luck with your travels down this road. It may get you back into casting like it did me!