Pumping stars with high metal content

[Merlin]

Bright Streamer.(Very impressive effect,)

 

I used this stars competition formula in my shells. Formula taken from hardts book,

 

Effect: - Bright Streamer

 

Composition in weight:

 

KNO3 29%

Charcoal. 34%

Ferrotitanium. 25%

Sulphur. 6%

Dextrin. 6%

 

Screen the ingredients together few times. (I never ballmill above composition) screened comp make a longer tail as well as more glittery effect & get a longer hang time.

Pump the stars, damp composition in 75/25 W/A. Use BP-Silicon prime.

Edited by Mumbles, 17 No

 

This formula has 25% metal content. I had to sub a bit of 120 mesh Ti as I ran out of ferro. The comp requires pumping. I don't want to ruin my Wolter star plate. Should I abandon this comp?

Edited August 23, 2016 by Merlin

[dagabu]

There are a few good tricks that work well in pumping high metal comps. One is to use a wooden dowel to push all the comp down into the plate holes followed by wiping out the top of the holes (rammer with a rag) to free them of the metals, dropping in a disk to act as a wiper and press normally.

 

The second is to do the same but use a pinch of charcoal above the comp before pressing.

 

The third is to use tight fitting delrin pucks into each cavity or have the pins topped with delrin ends.

 

Personally? I pump high metal comets with a split PVC pump body and a delrin rammer. A few hits, turn the screw, the comet drops out. PVC is cheap and the delrin rammer lasts forever.

[calebkessinger]

I would cut that instead of running it through a star plate.

Unless a guy is 100% certain of the sizing and shape of the metals you are using it's just not worth the risk. Yes.. people get lots of different comps through star plates but it only takes 1 piece of metal to kill a plate or pump.

[dagabu]

I dont think you can cut a 25% metals loaf, it just shreds.

[AzoMittle]

You can definitely roll them though! I just rolled a large batch with 17% (mixed) metals not too long ago. SGRS helps.

[Merlin]

Yep but this particular comp must not be over wet.

I have only rolled 3 or 4 lbs so I am not confident yet about over wetting. My plate is steel so I pumped. The nitride coating had a couple scratches here and there but nothing serious. However, next time I will take your advice and roll. Got plenty SGRS. Have you rolled high C content successfully?

Thanks for the replies. I got away with it but won't risk it again.

Edited August 23, 2016 by Merlin

[AzoMittle]

C as in Charcoal, yes? Highest I've gone is 45% charcoal (35% airfloat, 5% 80 mesh, 5% 36 mesh) + 5% lampblack. It rolled fine, dusty, but fine.

 

Dextrin is great for how cheap it is (basically free if baking it from corn starch) and works great for pumping, cutting, etc. but I always prefer to roll with SGRS. I've tried rolling with red gum, phenolic resin, vinsol resin, NC, and toro method but never had much luck or anywhere near as ease/success as SGRS, just my two cents, whatever works for you.

[OldMarine]

When pressing metal bearing comps reserve about 10% of the comp without metal. After loading your plate, press the pin plate in about 1/16" then fill with the non-metal comp. This will prevent metal from binding between the pin and wall which is what ruins your star plate. I learned the tip on FW and it's worked great.

[Merlin]

Thanks to Azo, dag, Caleb and oldmarine, lot of good suggestions. A pinch of charcoal or reserving a bit of the comp without metals sounds easiest. I was just plain lucky today. But if they can be rolled that would be faster with such a large batch as a have a dedicated cement mixer for rolling.

When I saw those bright long hanging horsetails I became hooked on giving it a try.

By the way Caleb you are super fast on getting orders out and much more reasonable on shipping than the big outfits. Mikee is pretty good as well. Thanks again.

Edited August 23, 2016 by Merlin

[calebkessinger]

Thanks Merlin.

I"m still behind on orders from PGI and a couple guys are waiting on a star plate I didn't have built yet.. I sure don't like making people wait but I guess as I grow it's gonna happen every now and then.

 

The scratchy metals in pumps and plates scare me. Even a coated one will look like an alligator got ahold of it if the metal gets pinched or rolled up in between the ram and sidewall. I've started using a lot of delrin in my pumps to help but they still won't just eat spherical ti or something like that.. I'VE TRIED. Paper or plastic wipers in single pumps work well.

[Merlin]

I've started using a lot of delrin in my pumps to help but they still won't just eat spherical ti or something like that.. I'VE TRIED. Paper or plastic wipers in single pumps work well.

 

Acetal homopolymer resin. You mean to say the the rams are polymer and the plate is aluminum?

That's interesting. My Glocks and Kahrs hold up pretty well. You may be on to something.

[Arthur]

I have used syringes as disposible pumps with High Ti comps. They get scratched then you bin them. Just cut off the needle end first.

[calebkessinger]

Yep, the rams either all acetal or tipped with it. Commercial pumps are made that way sometimes. It holds up very well and there is no gaulling from the aluminum on aluminum rubbing. It is double the price of aluminum but still cheaper than sending everything off to get coated.

[Mumbles]

The above formula (Nishiki Kamuro) cuts just fine for what it's worth. It's a little rougher than normal, but can be cut without issue.

[Merlin]

I have no problem with cut stars unless the effect needs to burn out at the same time. I can't cut precisely but with this effect the stars are dumped so variations in cut star size would not matter. I actually wanted to cut them butt in further reading on the effect it was stated that the amount of water used to bind them is critical to the effect and that a minimum amount of water should be used to bind and that to achieve the effect pumping is required. I thought that did not sound right because I have understood high metal stars will cause galling of the pump.. Being determined to achieve the effect I pumped them. My pump is steel and was not ruined but there are a few scratches on the coating. Next time I will reserve a small amount of comp without metals to top off the cavities to protect the rams.

Having said that, my information about over wetting may not be true in which case I would definitely cut them.

Edited August 24, 2016 by Merlin