Making Sparkplugs: My first 100 primers

[P Flados]

Over the past 40 some odd years I have discarded a lot of aluminum powder as an unwanted byproduct of metalworking. Of all of the tools I have used, I thought about those that produce fine powder while removing material.

First I tried a belt sander and was not happy with the results.

Yesterday I tried using my small benchtop bandsaw with a fine blade. Before cutting I cleaned out the inside of the bandsaw and the inside of my shop vac. I connect them up and I made lots of cuts in some 1/16" thick scrap where the cut off strip of AL was about one blade width. In less than 1 hour I had set up, made and sifted the powder and cleaned up. Yield was around:

• 40 grains of 60 - 80. This is too big based on info at MeWe. If I get a coffee grinder, I will see if I can use this stuff to make the recommended size.
• 20 grains of 80 - 150. There was not much 80 - 100 (which is still bigger than recommended) so I threw it in with the 100 - 150. The 100 - 150 is the recommended range.
• I collected some less than 150 just because it was there. This would probably be good with just a small amount mixed in with my NC for my EPH 20 type applications, but I am a little hesitant to try. It is so fine, I worry about oxidation. Since we wet the mix to activate it, this really fine AL might degrade pretty quick.

I can probably shift my yield more to the recommended mesh size by reducing the speed of my cuts. Given that I am not planning on making primers for rifle or magnum pistol use at this time, this could be more than I will ever need. I certainly have more than enough to play with for enhancing my pistol primers. Making powder this way was much less work for me than hand filing.

[notenoughguns]

I don't know if it's been mentioned before but that grey powder you mix in Tannerite is nothing more than fine aluminum powder which would give you more than enough to make 1000's of primers from a 1 lb target , just saying !

[blackthorn]

This thread needs to become a sticky!

[Castloader]

For both Pflados and Castloader, are you resizing your primer cups or just hammering out the dents? As far as grinding NC, I'm trying to decide between the puck/acetone or coffee grinder method.

And Happy New Year to all. May 2022 be better.

I am just hammering out the dents, but I avoid any primer cups that have any mushrooming. They don't work with my primer loading station. I may try to resize eventually if I need to.

[Castloader]

Other than keeping as dry as possible, I am not sure there is much else I would want to try. Also, for the AL powder I think the desired size is big enough (80-100 I think) to be less of a problem than for a really fine powder.

Dry powder is not the goal, unoxidized powder is. That's where the charcoal comes in. It absorbs oxygen. Wetting naked AL powder may or may not accelerate oxidation, I'm not sure.

Yesterday, I used a belt sander (with 80 grit abrasive) to generate some more powder from scrap AL. It took more work and generated less powder than I hoped for. I have made and discarded lots of AL powder in the past during metal working activities. I am considering trying a very fine blade on my small bench top band saw with very slow advance speeds.

If I get into making AL powder, it'll be with a ball mill. I was thinking we wanted exceptionally small particle sizes, on the order of a few microns. I'm sure we'll both be trying it shortly, so we'll find out what bigger sizes do, if anything. I have my 4th batch started, and this one will be with AL powder stolen from a Tannerite pack I have. I'm sure it's already high quality, so it'll be something of a benchmark. Plus, there's enough in one packet to make quite a lot of primers at 5 grains per batch.

I recommend avoiding grinding AL to get powder, either with sandpaper or a grinding wheel due to contamination. I know AL is pretty soft, but especially sandpaper degrades as you use it and it'll get grit into your AL powder. I doubt the grit will really cause too many problems, we have Pyrex powder as a frictionator, but it's a known, measured quantity. I wouldn't want random grit from other sources thrown in if I could avoid it.

[Castloader]

Castloader, I really like your idea of the 3mm plate. It seems to make the process much quicker, neater and easier. I'm curious; what does the ground glass do, anyway?

It increases friction in the chemical compound which helps ensure ignition. It was left out of earlier recipes, but sometimes the firing pin strike would not set them off.

I'm planning to make a batch soon with powdered AL instead of pyrex. It supposedly does the same thing as pyrex while also generating a lot more heat. The AL will send a shower of incandescent particles through the flash hole. This is supposedly a fix for the hangfires experienced with slow-burning powders. We'll test it out as we continue this work and report back.

[Castloader]

At this point I am not convinced one way or the other if cup sizing is worth the effort.

Agreed, the only reason I would do it is to remove the mushroom from some of the cups that experienced a little pressure. Right now, I don't know which cups are SPP vs SRP, and I assume the mushroomed ones are SRP's probably from 300BLK load development. I have thousands of un-mushroomed cups to use, so no need to go there right now.

[Castloader]

I can probably shift my yield more to the recommended mesh size by reducing the speed of my cuts. Given that I am not planning on making primers for rifle or magnum pistol use at this time, this could be more than I will ever need. I certainly have more than enough to play with for enhancing my pistol primers. Making powder this way was much less work for me than hand filing.

I'm interested to see how it works out!

[Castloader]

I don't know if it's been mentioned before but that grey powder you mix in Tannerite is nothing more than fine aluminum powder which would give you more than enough to make 1000's of primers from a 1 lb target , just saying !

Yes, coming soon.

[P Flados]

I was back in the "Homemade Primer Course" document and I found: "80 mesh (60-100 mesh will work) aluminum powder". This is recommending particles quite a big bigger than what I saw over at MeWe.

I did another run with the bandsaw and got AL particles size shifted a little closer to what we want. I am still getting more 60-80 than I want. The 60-80 is pretty course. I may try cutting through thinner material.

Regardless of what I am getting and given the mixed recommendations I found, I am thinking I will try 25% each of 60-80, 80-100, 100-150 and 150-200.

I re-sifted everything and separated it all into zip lock bags with 60-80, 80-100, 100-150, 150-200, 200-325.

[Castloader]

Good video. Dang that guy needs some PPE though. His glib remarks about the “free cancer” are a bit unsettling. I think I’m juggling enough toxicity at the moment.

[Castloader]

Well, I had my first primer go off while priming a case. My fourth batch is EPH25. I used 1.7 grains of aluminum from a .5lb Tannerite mixing packet. BTW, the whole packet weighed 187 grains, so I figure I have enough aluminum powder to make nearly 100 batches of EPH25 primers, (10,000 primers). It came out as air float powder. The first thing I noticed with EPH25 is that the priming compound was slightly more resistant to wetting with the alcohol/water slurry. It would get fully wet, but it seemed less sponge-like and took longer for the wetness to travel around the mixture. As such, I ended up using more water in each cup. Other than that, the only difference was that I tried hard to get some uniformity in the anvil seating. Instead of smashing the anvils down as hard as I could, I focused on getting them really level with the 3mm plate. I'm thinking about making a priming strip to run through my single-stage press. I think that will help with the process. I dried in my Instant Pot again, and that will remain my standard method. I noticed the bottom of the bowl gets quite hot, so I used a small stainless ramekin dish as a buffer. I want the air temp to dry them out, not conduction from the bottom. Worked great, overnight they were ready. I have 50 9mm casings and 50(well 49) 38SPL cases primed for loading. Based on the one that went off, power should be no issue for this batch. I'm planning to use a variety of slow powders for some 38SPL, and repeat the HS-6 test with 9mm to see what happens. I have IMR 4227, Alliant 2400, and A#9, for my slow powders. We'll see what happens.

[mvintx]

Well, if there is a possibility of capping off a primer during seating, I don't think I'll be doing that in a progressive press. Might be safer to do the process separately.

Any idea as to what mesh the aluminum powder is from your exploding target? Wonder if it made any difference in the wetting and seating difficulty? I've got a couple of 2-1/2 lb Star Targets that have been on the back shelf for several years but not sure if I want to scavenge the aluminum powder from them if it's not of an appropriate mesh. Exploding targets might have some use in the future.

[P Flados]

From what I have seen, aluminum powder made in a ball mill is way too fine for primers.

The AL particles are supposed to be large enough to start burning and then stay burning as they penetrate into the gunpowder to get the main charge ignition started in as many locations as possible. When you see pictures / videos of the flash from commercial primers, the streaks/sparks are aluminum (or similar) particles.

Unless we can get lower rates for dry primers going off when being seated, a progressive sounds like asking for trouble.

[P Flados]

I fired a mix of reloaded primers at the range. All 130 went off on first strike, but two were partial ignition with very low bullet velocity leaving the gun.

I am mentally going through my choices for what changes I should make to get improved reliability.

I will probably order a cheap hand coffee grinder to try to get a more consistent particle size with mechanical processing only on flake powder (Promo) followed by sifting to get desired particle size. I worry that a clump of larger NC particles in the "pinch zone" can result in a poor pellet ignition.

I will probably also go to EPH 25 mixes instead of EPH 20 mixes.

Until I get happy with consistency, I should probably also be very careful with the drying sequence. I am thinking at least 3 hours of 120 degf followed by at least 12 hours at ambient and 1 hour of 110 just prior to loading. The PID controller for my toaster over (set up for powder coating cast bullets) regulates very well in this mode and I recently re-calibrated the thermocouple (adjusted it to read 212 degf in boiling water).

[Tedly]

Thanks for sharing

[Castloader]

I picked up an electric coffee grinder today for $12. I threw some Power Pistol into it and let it rip. I selected PP because I’ve heard that there aren’t any burn-controlling additives to slow it down like flash suppressant. I just dumped some in, probably a tablespoon or so and went at it for a while until the motor started to feel slightly warm, maybe two minutes or so. Then I dumped on a 100-mesh screen to sift. I was surprised at how little made it through. Fast forward 20 minutes or so (actually all day, but I picked it up and put it down so many times I’m estimating) and I’ve got about 20 grains of 100 mesh nitrocellulose. This is far and away better than mortar and pestle. 20 grains will let me make 400 primers, so the work was well worth it, and it sucked way less than grinding in the miserable mortar & pestle.

I’ll report back after I shoot these EPH25 primers. I doubt the fine AL size will cause problems, but we’ll see. If it does, I’ve got this new coffee grinder and I’ll go at some aluminum foil looking for a courser mesh.

[Castloader]

By the way, I noticed that I’m now a “Boolit Man” vs a “Boolit Buddy”. Does that kind of thing happen automatically?

[No_1]

By the way, I noticed that I’m now a “Boolit Man” vs a “Boolit Buddy”. Does that kind of thing happen automatically?

Yes, once you reach 75 posts.

BTW, congratulations - This (your) post is now a sticky!

Robert

[Castloader]

I'm quite humbled actually, and grateful to all the good folks here that have so enriched my life and taught me so much. Cheers everyone!