This is a place where having a high thermal mass works in your favor. Even when the element cycles down the lead retains sufficient heat that the curing process is still taking place.Originally Posted by OS OK
It also explains why a test run with a few bullets can give significantly different results when a full tray is run under otherwise similar conditions.
NRA Endowment Member
Armed people don't march into gas chambers.
I DO use videos at times to learn things, but I far prefer the written word and illustrations.
As far as partial cure, full cure, mfg instructions, all of that.
The mfg is marketing a product that sometimes is designed for full sun and weather exposure, maybe even salt water, we are not asking that of the coating typically. If we were to strictly follow the mfg suggested process we would only be using spray ES process.
The PC process for bullets seems to be really tolerant of all kinds of variables.
Bill
Both ends WHAT a player
I know...I put all the trays in now, fully loaded or not and set it for 15 minutes @ 400*F. That seems to work fine.
Lots of people here getting 'wigged out' over Elvis changing the bake times...his intent was to find a way to keep the high BHN everyone strives for by water dropping from the mould. Instead of being complimented for his determined experimentation to find another way...here at CastBoolits he gets berated!
I wonder why so many members are like that on this forum?
a m e r i c a n p r a v d a
Be a Patriot . . . expose their lies!
“In a time of deceit, telling the truth is a revolutionary act.” G. Orwell
Nothing personal against Elvis, I don't do that. And I certainly don't have a problem with experimenting, after all that had to be the way the first PC bullet came to be. I don't have a problem with opinion, but I do have a problem with any posts that portray an experiment, which is contrary to well known standards and establish practices, and not stating this is an experiment. YouTube is full of these videos, some even dangerous. I never will forget the one where the rednecks put on a bullet proof vest to see if it would stop a 9mm, it didn't.
For me I know the PC information Elvis posted is wrong, but a lot of new people to powder coating I guarantee have watched this video and accepted it as fact. I personally don't like "Fake News".
Last edited by Dragonheart; 05-01-2018 at 03:45 PM.
People "knew the world was flat" for many years. Some still do! When someone shows a different way to do something and has taken the time to actually do it and find it works for them, there is no fake news. He suggests you try it for yourself (or not) and then criticize and correct if warranted. I have tried the 275 degree at 15 minutes with Eastwood Ford light blue and can say the batch I made shot fine out of my Ruger PC carbine.
I have previously always baked at 400 for 20 minutes and that works great but I'm always open to suggestions.
Jim
"The problem with quotes on the internet is that it is hard to verify their authenticity." - Thomas Jefferson 1803
Hi Jim,
If it works for you and you are happy then so am I.
I would like to point out that those doing an intentional partial cure do it so a second coat of powder will flow into the first coat and bond. A partial cure is achieved almost exactly as you describe, not my opinion, the information on how to partial cure came directly from the techs at a leading powder manufacturer.
I have voiced my view on the subject and see no need to say more.
Hello,
I have just started looking into powder coating cast Boolits. This method looks interesting, what oven gives you the temperature control necessary for this method? I am assuming he is using a PID controller for temperature monitoring.
A convection oven has been recommended for best temp. control and a digital control seems to give the best regulation. That said, they are more expensive ovens. Many use whatever they can scrounge at the GoodWill store as in a toaster oven.
An accurate thermometer is a must in my 'OCD'd' mind. Dragonheart turned me onto this one...
A PID would be the best choice but depending on the type oven you use, you may have to go inside and re-wire a little...if you use a convection oven you'd have to isolate the element and control it and make sure the circulation fan runs the whole time the oven is on.
You'll have to discover for yourself how far 'off the desired setting' any type of mechanical temp. control setting is...mine was off 70*F. Once I discovered that I used a paint pencil to mark the temp. dial to 400*F.
a m e r i c a n p r a v d a
Be a Patriot . . . expose their lies!
“In a time of deceit, telling the truth is a revolutionary act.” G. Orwell
OK, I said I would keep my mouth shut, but this post proves my point. Someone new to Powder Coating is going to start out using an undercured process, typically know in the industry as a partial cure. The partial cure is used when multiple coats are applied, not what you want for a finished product.
The full curing process allows synthetic polymer chains within the formulation to bond with one another, this process is called cross linking and is the reason powder coating is so durable. Unless powder is allowed to run through a full cure cycle, the cross linking process will not be complete and the durability of the coating will be compromised.
Alaskan100, do yourself a favor and read old posts on how to powder coat the proper way.
Hi, I have to concur that this type (brand) of oven temp gauge is really an accurate gauge & works great! Now this brand of gauge does make others that are a tad cheaper and they look like this model as well but.... from the reviews I have read the cheaper ones do not work & are not as accurate. The model I have is as "OS OK" shows in his pic and the model # is: #5921N. The reviews I have read on this model is really good. I bought 2 of this type of gauge mainly since I didn't have a PID yet. I have another (a little smaller) toaster oven my daughter gave me but it isn't convection (I need to look into installing a fan into this Sm. oven). That is why I bought the 2nd gauge. I haven't tried or tested the 2nd(oven) with it as yet, but I will be very soon. I do now have a PID from Hatch also with a 400*F probe for the PID as well.
My slightly bigger oven is Black & Decker Model & it is convection and I have tested it with this gauge & it works great & is accurate. What surprised me is that the thermostat was very close to the desired temperature & held it there. I have used the oven 5 times so far with only slight fluctuations, ranging from roughly 385* to 400*. I was lucky I guess at least so far! SharuLady
A convection oven has been recommended for best temp. control and a digital control seems to give the best regulation. That said, they are more expensive ovens. Many use whatever they can scrounge at the Goodwill store as in a toaster oven.
An accurate thermometer is a must in my 'OCD'd' mind. Dragonheart turned me onto this one...
A PID would be the best choice but depending on the type oven you use, you may have to go inside and re-wire a little...if you use a convection oven you'd have to isolate the element and control it and make sure the circulation fan runs the whole time the oven is on.
You'll have to discover for yourself how far 'off the desired setting' any type of mechanical temp. control setting is...mine was off 70*F. Once I discovered that I used a paint pencil to mark the temp. dial to 400*F.
PIDs are great, but they are really overkill for bullets if your toaster oven comes to temp and will stabilize; the Taylor thermometer moves fast enough to tell you that. I put a PID in a 30" wall oven because the oven's all digital control panel was shot and the reason I received a really good oven for free. Now it is a great PC oven for larger projects.
BTW: Here is another one of my secrets. Taylor also made some mercury & glass/stainless serviceman's thermometers for service techs that are very accurate. You can find them on Evil Bay from time to time, usually around $12. Do a "Vintage Oven Thermometer" search. The old Taylor porcelain/mercury & glass thermometers are also a find; old stuff like this works so much better than new.
I’ve got a new package of Eastman Ford blue that I’m anxious to try. I tried powder coating a few years ago and even bought the harbor freight PC gun but it was too much trouble. I tried the shake and bake and it worked OK but I was trying to stand them on end and that was frustrating.
This time I’m going dump them all into my mesh screen shake a little bit and try 415 for 20 minutes. One thing I’m looking forward to trying is to fatten up my Lee 310 boolits for my 44 super Blackhawk. I have two 310 molds from Lee and both of them throw small boolits.
I have a few hands full of old 310 gr boolits that I think I’ll try out tomorrow with the Eastman.
Wish me luck!
Plata o plomo?
Plomo, por favor!
Standing bullets on end is frustrating unless you use the right tool. Try the self closing tweezers, but not all of these tweezers are equal. Find one that holds tight,but the spring action is not so stiff that you get hand fatigue.
Attachment 220289
Hi Dragonheart,
Yes, I got a pair of the self closing tweezers that holds tight but the spring action isn't too stiff to operate. They work good. The fine small amount of teeth on it also doesn't leave any marks when picking up the boolits to place them on the trays. Even so I do coat the working end with some powder just in case.
BTW, ty for the secret tip on the "Vintage Oven Thermometer".
SharuLady
Note the end of my tweezers have been ground down so I can lock on in the lube groove. I do dip the end into powder which is more important when I spray, as the coating is more fragile and can be disturbed. The PC on the bullets that come out of my tumbler is nowhere near as fragile.
Powder coating - 2 stage method
Pre-heat oven to 115 degrees C.
Tumble bullets and powder in a number 5 container
Dump an even layer of bullets and excess powder onto a mesh baking tray - save excess powder
Place tray in oven for 8 to 10 minutes - the bullets should all have a wet look, this ensures that the powder has melted and is sticking to the bullets.
Dump the bullets from the oven into water, at this point the wet powder coat sticks to the bullets and not to other wet powder coat allowing the bullets to separate easily.
Once you have stage 1 coated all of your bullets you can handle them without the powder coating coming off the bullets, they can even be stored for months in this state waiting until you complete the second stage.
Stage 2 is just the normal 200 degree C. @ 20 minutes and then water dump.
The magic thing about this is that you can handle the bullets with your hands to stand them on a baking tray - no loss of powder coat - any uncoated spots from the first bake are now coated as the powder melts and flows to get complete coverage.
The results are perfect bullets that are easy to handle during the entire powder coating process. It does take time to stand bullets on the tray, I use a guide to ensure they are evenly spaced but the bullets are perfect and I would have no problem selling bullets coated this way.
Recovered bullets retain coating, I use soft range scrap which is very leady - 115 gr rcbs 9mm drops at 123gr and I have used this process with 9mm 115 and 140 gr, 38 special 150 swc and 130 gr bnwc and 45 colt 250 and 270 gr (hot loads). 9mm is the highest pressure and no problems there.
Doing a partial cure where the powder flows then an under cure of 200 degrees is not following any powder manufactures specifications. A shiny coating is absolutely no indication of a properly coated & cured polymer.
It is no skin off my nose when others experiment and they are satisfied with what I consider poor results, but there are a lot of new people wanting to give PC a try for the first time. Postings and videos that offer substandard shortcuts and just bad information do a disservice to any place where those seeking factual information go.
The problem with the dump method is when a full cure is done at 400 degrees substrate temperature for a minimum of 10 minutes the polymer reaches full cure and is tough & hard like it needs to be. Then when the bullets hit the water they bond together and are difficult to impossible to separate, so posts like Elvis tout under cure the coating and it will break apart because the coating is soft. So what you have is an under cured polymer and not what the PC process is all about. If someone can show me a faster way to achieve the same quality results I am ready to listen, but an under cure ain't it!
Hi - the instructions given were in CELCIUS - 115 C is 239 F and 200 C is 392 F.
This process works and the single best thing is you do not have to use your tweezers.
I use the partial cure method to do just - partial cure - the bullets do not stick together at 239F BUT THEY WILL AT 400F
I do this so that I can handle the bullets without tweezers - they don't stick together and then I stand them up and bake them for 20 @ 400 F - coating works in a standard glock barrel in 9mm with no leading - if it works in that it's going to work in almost anything
First image shows partial cure and full cure bullets next to each other - partial are laying down
In the oven - after partial bake and ready to dump - notice how they are on top of each other and would stick if this was at 400F
In the tray after being water dunked - notice how they are not sticking together.
Standing them up to put them in the oven at 400F - they are still wet - makes no difference
Final result in the box and ready to use - I don't size these as they drop just fine due to the high lead content - the coating adds the necessary 2 thou to make them .357 which is what I run in the Glock with no leading.
Last edited by Chargerboy72; 06-24-2019 at 11:21 AM. Reason: extra information
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