Powder coating - basic chemistry.

[10x]

I had a great conversation with Charles Darnell yesterday. Charles has done extensive research on powders for powder coating.
His goal, to match copper guild bullet velocity with powder coated cast bullets.
He used a 30/06 and 220 grain Plain Base cast bullets. (Charles did not indicate what alloy he was casting, soft? Hard? Wheel weight? )

Charles comments were - there are two kinds of powder coat, polymer based, and polyester based.
The polymer based is the one to use, polyester gives some advantage over alox/wax lubes and higher velocity speed limit.
Polymer based powder essentially covers the bullet with a single carbon based molecule. He has used single and double coats of the polymer base powder and it has served him well.
The polyester based powder, while tough and durable, does not have the same chemical structure on baking that the polymer has. Polyester powder does not give as tough a surface on a bullet as does polymer powder coat.

This explains a great deal about the results I have been getting. And why some have claimed to have used powder coat to match factory velocity and accuracy.

With the alloys I have been using (Approximately lyman #2) wax / alox lube on the bullet gives a maximum speed of 1700 fps to 1800 fps (with gas check bullets) at which point group sizes start to increase in size.
Polyester powder coat has raised the velocity about 150 fps to 200 fps faster than where group sizes increase with Alox/was lubes - it also seems to reduce group sizes compared to Alox/wax at the same velocities.


Now my quest is to find polymer powder coat powder and see if I can duplicate what Charles has told me.
All of the powder coat I currently have on hand is polyester based. Polymer just may raise the bar with 224 and 225 caliber 37 gr and 55 grain bullets.


My score of the year - a Cuisinart® digital convection toaster oven at the local church thrift store for $3.
This find thwarts all my plans to convert a convection oven to PID temperature control.

Charles Darnell designed the Freechex series of gas check makers for those who are interested,
and no, he does not ship to Canada, or any place outside of the USA

 

[yomomma]

Good to hear he is still in the game.

There is also urethane powder. It is does not cover very well and goes on very heavy.

 

[BattleRife]

Polyester is a polymer. As are polyurethane and polyepoxides, polyethylene, polyaramids, polypropylene, polytetrafluoroethylene and nearly everything else that starts with the prefix 'poly'. Saying your coating is a polymer is about as specific and useful as saying it comes in a can.

 

[yomomma]

Polyester is a polymer. As are polyurethane and polyepoxides, polyethylene, polyaramids, polypropylene, polytetrafluoroethylene and nearly everything else that starts with the prefix 'poly'. Saying your coating is a polymer is about as specific and useful as saying it comes in a can.

Maybe its a sales term that the powder distributer uses, science guy.

 

[10x]

Polyester is a polymer. As are polyurethane and polyepoxides, polyethylene, polyaramids, polypropylene, polytetrafluoroethylene and nearly everything else that starts with the prefix 'poly'. Saying your coating is a polymer is about as specific and useful as saying it comes in a can.

This the polymerization bonding process is what I am referring too - rather than an ester bonding process

https://wikidiff.com/polymer/polyester

the difference between polymer and polyester is that polymer is (organic chemistry) a long or larger molecule consisting of a chain or network of many repeating units, formed by chemically bonding together many identical or similar small molecules called monomers a polymer is formed by polymerization, the joining of many monomer molecules while polyester is any polymer whose monomers are linked together by ester bonds.

Thank you for pointing this out

 

[f55]

Why didn't Charles give you a source to purchase polymer pc?

 

[10x]

Why didn't Charles give you a source to purchase polymer pc?

Not yet. The conversation was only about the difference in polyesters bonds and poly monomer bonds. Gas checks, Freechex dies and construction, and we didn't get around to discussing sources of powder coat powder.
I will be asking him about sourcing polymer powders that result in a monomer coat rather than a polyester coat in the next conversation I have.
Charles is a wealth of information.

 

[10x]

Why didn't Charles give you a source to purchase polymer pc?

Cerakote® is the long chain carbon polymer

 

[yomomma]

Ceramic...that explains a lot about his findings

 

[BattleRife]

Not yet. The conversation was only about the difference in polyesters and poly monomers. Gas checks, Freechex dies and construction, and we didn't get around to discussing sources of powder coat powder.
I will be asking him about sourcing polymer powders that result in a monomer coat rather than a polyester coat in the next conversation I have.
Charles is a wealth of information.

I am sorry, but either you lost your understanding of what Charles was saying or he is useless as a source. The things you are saying here make no sense.

'Mer' is a Greek word meaning unit. 'Mono' means one; 'poly' means many. Thus a monomer is a molecule consisting of a single chemical group (one unit). A polymer is a molecule consisting of a chemical group repeated over and over (many units).

Monomers join together to produce polymers. You cannot have "poly monomers", it is a contradiction in terms. I doubt a monomeric coating can exist. Even if it could, it wouldn't be called a monomer. Chemistry only refers to them as monomers because of their potential to link together to form polymers, if you don't follow through with polymerization why bother calling it a monomer?

 

[10x]

I am sorry, but either you lost your understanding of what Charles was saying or he is useless as a source. The things you are saying here make no sense.

'Mer' is a Greek word meaning unit. 'Mono' means one; 'poly' means many. Thus a monomer is a molecule consisting of a single chemical group (one unit). A polymer is a molecule consisting of a chemical group repeated over and over (many units).

Monomers join together to produce polymers. You cannot have "poly monomers", it is a contradiction in terms. I doubt a monomeric coating can exist. Even if it could, it wouldn't be called a monomer. Chemistry only refers to them as monomers because of their potential to link together to form polymers, if you don't follow through with polymerization why bother calling it a monomer?

You win!

 

[hatman1793]

Hello 10X.
I have had great success with Emerald Coatings (Palmerston Ont.) Their "tool blue" gives an outstanding coating for pistol & rifle bullets. Plus, their clear coat works well too. Both coatings fully encapsulate the bullet & most importantly, the base.

Recovered bullets show no base erosion suggesting there is no lead vapourization.

 

[Bassmaster]

Another vote for tool blue ^^^^works well for the dozen or so cals that I cast for including .223

 

[10x]

Hello 10X.
I have had great success with Emerald Coatings (Palmerston Ont.) Their "tool blue" gives an outstanding coating for pistol & rifle bullets. Plus, their clear coat works well too. Both coatings fully encapsulate the bullet & most importantly, the base.

Recovered bullets show no base erosion suggesting there is no lead vapourization.

I am using the black and Red from Emerald coatings. - they give me better accuracy and a higher velocity speed limit than the wax/alox lubes.
Mr Darnell told me that he used a monomer powder coat that allowed him to match factory velocity with 220 grain 30/06 ammo.
Some have been taking 0.224 bullets up to 2500 fps or more with powder coat with success.
The colour of the powder coat should not matter,
I have not done extensive testing on higher velocity with powder coated bullets - at standard cast bullet velocities they seem to preform more consistently giving smaller groups.
Right now I am looking to drive a 9.3 , 285 grain cast bullet at about 2000 fps to duplicate factory velocity. I am powder coating these bullets (single coat) but will be doing a double coat and trying that.

I would be partial to using clear coat as that may give a stronger bond on cooking as there is no colourant to interfere with the molecules bonding. Or possibly the chemical composition of the power results in a blue colour on heating and bonding. I don't know the basic chemical structure of the powder or if the color is involved in the bonding reaction.

 

[handofzeus]

Has anybody tried Snow-Jet polymer spray? It's for snowblower chutes and the like. I was wondering if it might be an economical way of preventing leading. It seems create a polymer film that prevents adhesion. My real question is whether or not it would prevent leading.

 

[kelseyscooter1]

Hello 10X.
I have had great success with Emerald Coatings (Palmerston Ont.) Their "tool blue" gives an outstanding coating for pistol & rifle bullets. Plus, their clear coat works well too. Both coatings fully encapsulate the bullet & most importantly, the base.

Recovered bullets show no base erosion suggesting there is no lead vapourization.

good day..... which clear coat from emerald works the best?

 

[flashman2]

good day..... which clear coat from emerald works the best?

I've only used glass clear and had nothing but perfect results.

 

[flashman2]

Charles comments were - there are two kinds of powder coat, polymer based, and polyester based.
The polymer based is the one to use, polyester gives some advantage over alox/wax lubes and higher velocity speed limit.

Sorry, Charles is out to lunch.

There's far more than two kinds of powder coat. There's epoxy, acrylic, poly hybrid, polyester and polyurethane, probably more. I've never heard of any being called just polymer. The two main categories are thermoset and thermoplastic, but that doesn't sound like what he's referring to.

I'm assuming he meant that polyurethane is the one to use. That's contrary to my experience, and the conventional wisdom. I've noticed no accuracy or velocity difference with urethane, but it doesn't shake on near as well as poly TGIC.

This isn't voodoo or rocket surgery, it's just frigging powdered paint after all.

 

[flashman2]

Recovered bullets show no base erosion suggesting there is no lead vapourization.

Leading doesn't happen from the base. It happens from gas erosion getting past bullets that don't fit tight enough. If exposed lead at the base caused leading, then every FMJ round would cause it something fierce.

 

[10x]

Has anybody tried Snow-Jet polymer spray? It's for snowblower chutes and the like. I was wondering if it might be an economical way of preventing leading. It seems create a polymer film that prevents adhesion. My real question is whether or not it would prevent leading.

I have had no leading with any of the powder coat products I have used. Velocities are up to 2000 fps with 200 grain bullets in a 9.3 x 57.
The nicest coverage is from Eastman powder coat ( a polyester bond)
I am looking for a supply of polymer bond powder coat


https://www.eastwood.com/hotcoat-powder-coating/powders.html

I have tried powders from Emerald, Princess Auto, KMS tools, and all seem to cover very well using the shake and bake method Not one has resulted in leading in my 9.3 x 57