Are 2nd coats worth doing?

[Manns50]

Just tried powder coating for the first time tonight. I watched Elvis ammo on YouTube do a huge batch, he didnt pay too much attention on how he placed them. I'm sure a lot of you have seen this? I mean it wasn't absolutely perfect but the coating was 99% it look like on his vid. The problem is it was about a week ago when I watch that video and I forgot he lowers the temp to 275 deg. I had forgot about this temporarily until they were done, had some of them stick together, and they of course leave a bare spot when I break them apart. Thats why he lowers the temp.
Also about half of them did not cover very well on the outer bearing surface rings of the bullet. The most important part. I think that was the lack of powder, I should've been more powder when I was coating/ swirling them.
Using Eastwood Ford Blue, just figured I would get peoples opinion on a second coat before I try it. I did them at the 400 for 20 min and some came out really well almost perfect. Others not so much due too the non coverage or leaving a place from pulling apart.

[rockshooter]

At this point, as long as there is no lube on them (I spray with One-Shot prior to sizing) it won't hurt to recoat them. They could of course be remelted/recast, but since they're already at the bullet stage, might as well just recoat. Prior to that, I'd size, load and shoot some, and see how they function. Might be just fine.
Loren

[Manns50]

Ok I might try it, thanks for your input. Does it still create an imperfection with the chip of where it was stuck together or does it flow smooth and fill in?

[poppy42]

Just make sure you don’t have to much on them. The first couple time I PCd I did 2 coats, boy did they look good! 100% coverage and the shine like $1,000 paint job on a Mercedes! The problem was none of the would chamber, gas checks wouldn’t fit, resizing didn’t make a difference, I seriously think it had something to do with elasticity of the powder coat. You run them through the sizer and it seems like they spring back! Wound up remelt about 500 bullets. Just saying too much powder coat can be a bad thing. If you can I would probably load and shoot a couple as they are now. No sense fixing something if it’s not broken! Five or at the most 10 rounds will probably tell you what you need to know. If the second coat screws them up not much you can doExcept re-melt them. Oh and don’t try removing the powder coat with some type of solvent. Been there done that and cleaned up the mess I made trying.

[Rapier]

I have been powder coating for a couple of decades, who taught you, that to ever mess up the base on a bullet was a good idea?

Try going to ACE and get a piece of 1/4” hardware cloth, use a large punch to round the holes. So that the nose fits in and stopps. Bend the sides into a box, tie the corners with stainless wire, turn the box upside-down. Forms your coated bullet, nose down tray or holder for the oven.
Make a long needle nose set of pliers with the nose heated red hot then bent in to just touch. These are used to pick up the coated bullets and place them in the bullet tray nose down.
Shake in an air tight large mouth container.
Bake for 20 minutes at 400. Cool, remove, recoat and rebake. No gas check required up to 2,600 fps.
Size using case lube to the groove diameter. I use auto chrome and wheel coating.

My 358 MGP guns (2) with RCBS 200g plain base flat nose shoot 3/10s inch at 100 meters at 2,600 fps with 1680.

[Manns50]

I have been powder coating for a couple of decades, who taught you, that to ever mess up the base on a bullet was a good idea?

Try going to ACE and get a piece of 1/4” hardware cloth, use a large punch to round the holes. So that the nose fits in and stopps. Bend the sides into a box, tie the corners with stainless wire, turn the box upside-down. Forms your coated bullet, nose down tray or holder for the oven.
Make a long needle nose set of pliers with the nose heated red hot then bent in to just touch. These are used to pick up the coated bullets and place them in the bullet tray nose down.

Shake in an air tight large mouth container.
Bake for 20 minutes at 400. Cool, remove, recoat and rebake. No gas check required up to 2,600 fps.


Size using case lube to the groove diameter. I use auto chrome and wheel coating.

My 358 MGP guns (2) with RCBS 200g plain base flat nose shoot 3/10s inch at 100 meters at 2,600 fps with 1680.

Ok I just googled hardware cloth, didnt realized that's what it was called. I pretty much understand everything except the needle nose plier modification. Any pics?

[fastdadio]

I have a needle nose pliers that are spring open. I find them much easier to use for boolits than a normal pair. When you're pinching and placing 100's of boolits at a time, my fingers get tired.
Like these.
https://www.amazon.com/Spring-Precision-Bending-Handcraft-Working/dp/B0833Y3KDD/ref=sr_1_4?keywords=spring+needle+nose+pliers&qid=1653179190&sr=8-4

I have on occasion, double coated a batch of boolits for poor coverage. The only ones that became tight to chamber because of it were the Lee bore rider design. The sizing die does not resize the bore riding nose, and they became tight to chamber. It was a small batch and I shot them anyway. They did fine.

[charlie b]

I stand up my bullets on a silicone baking sheet. I also don't shoot a lot of pistol bullets, mainly rifle, so my volume is a few hundred at a time, not a thousand.

When picking up bullets to put on the sheet I use a set of angled tweezers. I slip some shrink tubing over the tips and swirl them around in the powder a bit before using them. I've only done a few thousand that way but they work well.

Beware of the Elvis advice. You still have to cook the bullets at the mfg recommended temps to get a full cure.

I've never used a second coat. Just isn't needed.

[doghawg]

Manns50

I've been powder coating long enough to have almost used up my original pound of Harbor Freight Red. The stuff has worked reasonably well but most of my bullets have been lubed with conventional lube sizers and Lars Lube. My new order of "Signal Blue" powder arrived today from Smoke 4320 and I coated a couple batches in a Cool Whip container with a few Airsoft BB's. What a difference! Coverage very close to 100%. The remaining Harbor Freight may end up in the trash.

I stand mine up on a cake pan with nonstick tinfoil using a pair of needle nose pliers with no grooves in the tips. After they get an accumulation of powder built up they leave no marks on bullets. The convection oven is set at 400 and time is around 18 to 20 minutes. As you observed if the bullets are touching during the baking process they stick together so I'm going to continue to stand them up.

Sizing is with an old leaker Lyman 450. Rather than fix it I just run it dry with the powder coats. Lee's push through sizers work well too.

[Manns50]

Ya I'm not using the airlift BB's, they seem to coat fine without those. I did have to change what I was straining them with, I first used a mesh baking sheet for an air fryer but it was too course, scraping some of the PC away. Found one of those powder coated file holder and its smoother to the touch, works much better. My 2nd coat did ok but def try to avoid the 2nd coat in the future. First batch was really good but my 2nd toaster oven, temp may have been different or not sure what but they were not as good. Still experimenting with the two small toaster ovens I have and learning where the temp is according to the dial. I have a spare wireless smoking thermometer I may have to utilize get the temps spot on.... get consistent results. I'm determined to get this right, get away from the 45/45/10.

Using a Lee push through sizer and I tried some of them last night with the PC on them and seem ok. The bearing surface of the bullet is really thin on PC once push through the sizer, almost looks like its bare lead but I think its just thin and I'm seeing the lead through the PC.

How do the bases turn out when standing them up?

[Kraschenbirn]

Dump your HF powder and try to forget anything you may have picked up from Elvis then order some Carolina Blue from Smoke 4320 and follow his instructions to the letter. Do that and you won't ever need to even think about a second coat. Oh yeah, and if you're applying your powder by 'shake n' bake', use the airsoft BBs. You'll get a much more even coating.

Bill

[popper]

Just sort out the good ones and recoat the others, lightly. Or use some tumble lube LLA or BLL on them. Some times you loose coating when sizing also. I stand all mine, tried the dump once, not for me. I never turned down the temp, if air cooling, just wait until the temp is low. There is a point where the PC is not sticky and not hard. Doesn't work if WD.

[charlie b]

As long as you shake off the excess powder there is no issue with bases when stood up. When using plain base bullets I like to size them base first. Gas check bullets get sized nose first.

Yes, if the bullet is sized a lot the PC coating looks thin. Don't let the looks deceive you, the PC is still there. I like to size before and after PC. Gives me a much more consistent bullet, IMHO.

[bangerjim]

I size B4 and after here! I just like smooth shiny boolits. That is why I use ESPC 100% now. Even back when a bunch of guys & I on here were developing the shake-n-bake methods back in 2013, I only used ONE coat. Never have seen the need for two, but I do not use those weird metallic psycho powder some like to try. Many do not coat well with the pigments involved. I stick with the SOLID primary colors and bled for other colors based on the color wheel. You only need 4 colors of powder!

Forget that clown on utube! Most powders are engineered to cure at 400F for 10 minutes AFTER it turns shiny. That is all I EVER use. Never any leading or grease smoke or dirty barrels.............................since 2013.

Good luck!

bangerjim :Fire:

[Manns50]

Thanks for all the input greatly appreciated. No I have some HF red I bought yeas ago but I never used it. I have the Ford light blue hot coat from Eastwood currently, only thing Ive used. Seems to coat great just have to perfect the application and curing method. I will pick up some airlift BB's and maybe pickup some non stick foil. I cut up a silicone mat been using that for my trays, usually use two diff toaster ovens. One seems really close to dial temps but other is way off. So I will get out my spare smoking temp probe and I'll give it a go. I was using a temp gun as well but that's hard to get an accurate temperature. I had an old oven thermometer is what I was using but guarantee the accuracy. Seems like the temp is everything along with bullet placement. If it wasn't for them touching I think I would have perfect bullets so it's working OK just the application or method.

[charlie b]

Yep, I'd check the oven temp first to make sure you are in the right range. You are closer to great bullets than you might think.

PS and yes, even here in the desert I use airsoft BB's (from Smoke) to shake and bake. IMHO they leave a more consistent coating on the bullets.

[GregLaROCHE]

Single coat should be all you need if you are doing it correctly. A second coat can be used if you want to increase boolit diameter.

[Manns50]

I size B4 and after here! I just like smooth shiny boolits. That is why I use ESPC 100% now. Even back when a bunch of guys & I on here were developing the shake-n-bake methods back in 2013, I only used ONE coat. Never have seen the need for two, but I do not use those weird metallic psycho powder some like to try. Many do not coat well with the pigments involved. I stick with the SOLID primary colors and bled for other colors based on the color wheel. You only need 4 colors of powder!

Forget that clown on utube! Most powders are engineered to cure at 400F for 10 minutes AFTER it turns shiny. That is all I EVER use. Never any leading or grease smoke or dirty barrels.............................since 2013.


Good luck!

bangerjim :Fire:

Can you clarify what ESPC is? I'm sorry probably should know this.

[bangerjim]

Can you clarify what ESPC is? I'm sorry probably should know this.

ESPC is "Electro Static Powder Coating" done with an engineered static gun to apply powder evenly to any surface. It is how the powder is applied in industry. Not with tubs or BBs or shaking or holding your mouth just right.....just perfect coated every time.

If you ever have a question on an acronym used on here ( and we use PLEANTY of 'em!) there is a sticky thread of tons of them explained on here.

And there are sticky threads discussing ESPC vs. shake-n-bake methods.

banger

[Manns50]

ESPC is "Electro Static Powder Coating" done with an engineered static gun to apply powder evenly to any surface. It is how the powder is applied in industry. Not with tubs or BBs or shaking or holding your mouth just right.....just perfect coated every time.

If you ever have a question on an acronym used on here ( and we use PLEANTY of 'em!) there is a sticky thread of tons of them explained on here.

And there are sticky threads discussing ESPC vs. shake-n-bake methods.

banger

Ok that makes sense, thanks for explaining that to me. Ya I'm familiar with the process and have had items powder coated but never purchased the equipment.
I actually have an account that I just serviced their extinguishers, and I frequent a lot because of it. They are a large plant that does powder coating, one of their ovens is the largest in North America. They are next to a company that manufactures liquid holding semi tanks and they are separate businesses that work hand in hand.
As I was doing the extinguisher service I ask if they would sell me some powder. He said he's never had anyone ask but sure something could be arranged. Maybe need to look into that.
But they do items of all sizes, even down to walk in's on personal items. Interesting watching the process in a large scale, of items of all shapes and sizes on a hanging chain being drawn through the spraying process from guys spraying them and through the ovens.

[Manns50]

Redeemed myself today. Added some plastic pellets in with the shake of light ford blue, and stood a couple hundred or better up on their base, baked at the 400 for 25 min.
Came out great very happy. This is a .401 10mm BB RCBS mold.
Just hav e to take the extra time to stand them up, already spending a lot of time in the whole process.. might as well spend another 20 min get good results.
These still need sized of course.
300735
300736

[Daekar]

I had my first experience with 2nd coats this past week. I had done a poor job achieving coverage (very thin PC for some reason) on some Accurate 36-125L and they weren't grouping well... everything went to heck when I exceeded 1350-1400fps. A second coat got me to between 1600 and 1700fps. Totally worth the effort to save those batches of boolits.

Have never needed it before, makes me wonder if I should try it on others and see what happens to the accuracy and velocity ceiling...

[Manns50]

Yes I knew it was something I didnt want to do every time with a 2nd coat. Just had that first batch attempt with poor results and was trying to salvage them, was kind of looking for results of someone that had done it. The batch above was one the one and only coat course.
Interesting to hear the velocities. Ive not cast for rifle rounds yet, I have a 308 I want to reload with. I forget at what the velocity limits are on cast bullets, need to look into it again. Never really considered what they are with PC.

[rockydoc]

For best temperature control for baking I suggest a convection toaster oven and a PID. (Check the acronym sticky if you don’t know what a PID is)

[Dragonheart]

When I saw this post I just had to leave a comment. Hopefully this will help some first starting and if you need information on PC there are a lot of good posts available here, of course some not so good either.

First that clown on YouTube has set powder coating back to way beyond when I first started PC in 2012. Even back then every powder manufacturer stipulated a cure schedule of 10 minute minimum at 400° for standard powders. That 10-minute cure time does not start when you turn the oven on, when the powder starts to flow at approximately 150° or even when the oven thermometer or PID reaches 400°.
The timing starts when the load (bullets) surface temp reaches 400°. The load is absorbing energy so it has to equalize, this may taky a few minutes or closer to an hour depending on the load, oven, power, etc. etc..

When I coat 5-6K bullets at a time my two 230V heating elements will bring the oven air temperature in my PID controlled oven up to 400° in approximately 12 minutes and hold it to within a couple of degrees. But realize a PID is only controlling the air temperature in the oven, something you can do with a good glass thermometer in a well-sealed oven with a good thermostat. However, once my oven air temperature reaches 400°, it will take an approximate 35-40 minutes more for all the load (5-6K bullets) to equalize and reach 400°.

I monitor the temperature of the bullets with a couple of inexpensive thermocouples. Similar to this one found on here Amazon "Digital Thermometer Dual Channel Thermometer Temperature Thermometer with Two K-Type Thermocouple Probe Backlight LCD K Type Thermometer for K/ J/ T/ E/ R/ S/ N"

I simply cast the end of the K-type probe wire into a bullet then lay the bullet/probes in a tray with the other bullets. This is the most accurate way I have found to monitor the temp and assure full PC cure.

I do double coat full power rifle bullets to increase the polymer thickness. Handguns do not come close to rifle velocity’s and single coating has always worked for me.

BTW: Eastwood came up with the “start your cure timing after powder flow”, which is just more bad information. Eastwood is a retailer, not a powder manufacturer. That method may work if you are coating a motorcycle frame and once the powder shines you are happy, but PC shine does not indicate full cure, and is altogether different if you are depending on full cure of the polymer prior to loading it to 3600 FPS or 50K pounds of chamber pressure!

[charlie b]

Single coating rifle bullets work just fine. I've tested the .308 at 2400fps with no issues or even a hint of an issue with the PC or leading. Many others have gone faster.

I coat a much smaller quantity of bullets in my toaster/convection oven. Bullets are stood on their bases, approx 1/2" apart from each other, about 80 per load. The 'flow' guidelines that Eastwood specifies, or the total 20min cure recommended by Smoke, work fine for me. I am satisfied that when the air temp in the oven is at the desired temp, then a couple of minutes is all that is needed for the surface of the bullets to be at that same temp. I usually set the timer for 25min total. The extra 5 min is for me to be confident the oven is back up to temp after opening the door (yes, I have timed it with an accurate oven thermometer).

If you do large batches like Dragonheart, then you need to monitor the temp of the center of your batch of bullets as he does. Takes a long time for the heat transfer to reach that point, even with a forced convection oven.

[Dragonheart]

Single coating rifle bullets work just fine. I've tested the .308 at 2400fps with no issues or even a hint of an issue with the PC or leading. Many others have gone faster.

I coat a much smaller quantity of bullets in my toaster/convection oven. Bullets are stood on their bases, approx 1/2" apart from each other, about 80 per load. The 'flow' guidelines that Eastwood specifies, or the total 20min cure recommended by Smoke, work fine for me. I am satisfied that when the air temp in the oven is at the desired temp, then a couple of minutes is all that is needed for the surface of the bullets to be at that same temp. I usually set the timer for 25min total. The extra 5 min is for me to be confident the oven is back up to temp after opening the door (yes, I have timed it with an accurate oven thermometer).

If you do large batches like Dragonheart, then you need to monitor the temp of the center of your batch of bullets as he does. Takes a long time for the heat transfer to reach that point, even with a forced convection oven.

I do not double coat to prevent leading as a proper coated and cured single PC does that quite well and I single coat all handgun bullets.

I double coat rifle bullets to increase the build out to approximately three mills to prevent torque spin out on full power loads. Typical rifling is .004” groove to lands in depth. The Polymer is approximately equal and hardness to copper, but with a better bond. The build out was calculated by a PhD Polymer physicist and I have confirmed by testing the polymer will withstand 3600+ fps and 50k+ psi chamber pressure, which is the largest thing I have.

You are correct most using a toaster over with small loads can just do a guestimate on the time assuming they have first confirmed with a reliable thermometer that their over can actually reach 400° and hold that temperature without wild swings, many of these ovens can't do that and relying on the thermostat dial is not a good idea.

[charlie b]

I have never had an issue with 'torque spin out' with cast bullets, especially with powder coating. Just a matter of using the proper alloy for the job. So a single layer PC has always worked. I would suspect that rifling twist plays an important part in your data as well. Chamber pressure is much less of an issue when the bullet is sized properly. Bullet weight (less weight, more acceleration, less spin inertia) might be something for you to consider as well. I was only a licensed mech engineer :)

I agree that any oven needs to be checked with a thermometer or converted to use PID. Both of mine have done well once I figured out the dial setting to get the right temp.

[Dragonheart]

I have never had an issue with 'torque spin out' with cast bullets, especially with powder coating. Just a matter of using the proper alloy for the job. So a single layer PC has always worked. I would suspect that rifling twist plays an important part in your data as well. Chamber pressure is much less of an issue when the bullet is sized properly. Bullet weight (less weight, more acceleration, less spin inertia) might be something for you to consider as well. I was only a licensed mech engineer :)

I agree that any oven needs to be checked with a thermometer or converted to use PID. Both of mine have done well once I figured out the dial setting to get the right temp.

I was only a lowly industrial engineer, so I garnished my information from an individuals who actually spent a lifetime working with Polymers. As well as my on years in achieving three Master Rifle Certifications. My father in law, also a mechanical engineer with 17 patents to his credit, had a very apt statement he used often; You can always tell an engineer. You can't tell'um much, but you can tell'um. I found that very funny, but also quite true.

[mehavey]

BOTTOM LINE OBSERVATION:
If a single coat doesn't provide full/sufficient coverage, you need
either a different powder, or a different application method.

[charlie b]

....You can always tell an engineer. You can't tell'um much, but you can tell'um. I found that very funny, but also quite true.

Yep. Working as an engineer with many other physicists and engineers was sometimes a nightmare. :) Managing projects was even more 'fun' with such a collection of personality types :)

[charlie b]

BOTTOM LINE OBSERVATION:
If a single coat doesn't provide full/sufficient coverage, you need
either a different powder, or a different application method.

I do agree.