Problam pumping stars

[dynomike1]

The other day we pumped 16oz of 1/2" stars, as per Skylighter's 1/2" star plate kit. ( humidity 43% ) We started out with 1.25oz of distilled water, stirred everything up after screening pumped stars fell apart added more water got better added more water got better added more water to much so i dumped them on drying screen anyway after every 2 plates full had to add water. I guess if you add to much water they just take longer to dry. I lit some that broke apart yesterday and they burned hopefully we will get to build a couple of 3" shells Sunday. Looks like it's going to rain again so i'll have time If these shells go up and break right my goal at this point is to make more C6 + C8, TT, and Wilow.

[optimus]

Are you leaving the mix a while to activate the dextrin before pumping?

[Dean411]

Are you using hand pressure or a mallet? If so the stars will need 2 days or so to dry hard they will crumble until there completely dry. Using a hydraulic press makes them quite a bit more solid right out of the pump so they can handle more abuse but also need to dry completely.

[Col]

8% water/alc sounds about right. You`d need a mallet for a 1/2" starplate, putting 200lbs body weight on a single 1/2" starpump only equates to 1000psi on the comp.

[dynomike1]

We made sure we stirred it good i'd say 5-10 min at least. Mallet wasn't available at the time so i used a ball peen. My mallet came yesterday. But it seemed that when we used more water they didn't crumble when they hit the screen. Didnt know what the effect will be with more water.

[Dean411]

More water means longer dry time. Try elevating the pump just high enough to get the stars out without them having to fall, leave them sitting where u extracted them as long as possible then later on move them to the screen to finish drying. . Adding to much water becomes a moot point when there so wet that you might as well cut them.

[Col]

I add the 8% water/alc and run the comp through a screen a couple of times to integrate. The comp needs to be just damp enough that it stays in a ball when squeezed. I do the same for colour comps but use 8% denatured alc (meths) instead of water/alc.

Here`s half a kilo of 3/8" blond streamers and 200g of red stars, All hand pumped one at a time using a modified brass hose barb and a brass rod

 

Edited October 10, 2012 by Col

[dan999ification]

nice stars col you should see my rg1, yeah the water content needs to be low enogh for it not to ooze out when you press or ram it, just stay together with squeezing by hand, activate the dextrin with hot water and leave it half hour before working ( covered ) screening at the right time helps if its too wet or even to evenly wet it, keep it covered while woking, 1 for safety 2 keep it at the same moisture content.

8 percent is enough for milled charcoal comps i use no alc and have no problem they will dry in a few days at most.

 

Dan.

[dan999ification]

col, is meths ok for veline stars, acetone can be expensive and hard to come by on the high street, and how does it compare in drying time i imagine meths takes longer than three hours.

 

Dan.

[dynomike1]

Thanks Guy's I put all this info in my Tec Tips. I looked at them while ago and they are hard as a rock. If i am off tomorrow i will put them in a zip lock bag in the sun and see how much moisture i get. If everything goes right Saturday night we are going to put 2 3" shells in the air. if they work right C8 is what i will make next.

[Algenco]

charcoal stars take awhile to dry completly, patience will be rewarded

[Col]

I`m sure they`ll work great, C6/C8 are nice in their own right, adding 5-10% Ti or Fe-Ti gives you instant variety

Dan, i use acetone for cut stars (parlon bound), meths for pumped using the red gum for binder, They`re dry enough that you cant smell the solvent in a few hours, so you probably could use them the same day. I usually leave them overnight and hit them with a 2 step prime the following day. I dont use veline but i dont see why you couldnt do the same with them.

[dan999ification]

veline uses both red gum and parlon ( and dextrin ) pumps well and rolls with water but takes time to dry and stinks of chlorine which is why i ask about the meths suitability and drying time.

Acetone it is then but the stars can be fast burning when cut with acetone and binding with parlon, smaller slower stars equals more in a shell to me.

Anyone use meths with veline? Can it be done from a safety perspective?

Fast drying pumped stars ( not sticky ) is what i want.

 

Dan.

[Col]

As it has red gum you can use meths...and a paint respirator for the fumes The stars aren`t sticky at all, they pump easily and drop straight off the brass plunger without any encouragement. They`re a bit more rounded after priming.

Edited October 11, 2012 by Col

[Potassiumchlorate]

My experience is that dextrin is activated almost immediately, if you have alcohol in the water. SGRS is trickier although stronger in the end if done correctly.

 

I wish I had 43% relative moist here too. I only have it on hot summer days and icecold winter days

[Mumbles]

nice stars col you should see my rg1, yeah the water content needs to be low enogh for it not to ooze out when you press or ram it, just stay together with squeezing by hand, activate the dextrin with hot water and leave it half hour before working ( covered ) screening at the right time helps if its too wet or even to evenly wet it, keep it covered while woking, 1 for safety 2 keep it at the same moisture content.

8 percent is enough for milled charcoal comps i use no alc and have no problem they will dry in a few days at most.

 

Dan.

 

Dan, that's a great method for crystallizing out big chunks of oxidizer, and ruining homogeneity. If you're going to wet anything with hot water, you need to keep kneeding or stirring it as it cools to prevent this. This is true for blackmatch, polverone, comets, and all other things commonly wet with warm/hot water or paste.

 

I've found dextrin to be activated quite quickly as well as well PotassiumChlorate. The reason I leave my mixtures to sit for 20-30 minutes, especially with composition being prepared for pumping, is to ensure even water distribution. When everything is uniformly wet and distributed, things go much better and reliably.

[dan999ification]

i do kneed the composition when its cool enough to handle, normally in a plastic bag to save mess and water evaporating.

The stars have no visible nitrate on the surface and if anything burn fast.

However i have had the troubles you mention with the first few batches due to the method used.

So pumping veline...

When using meths to bind the stars, should it be diluted?

 

Dan.

[rwunn]

In many cases moisture problems can be mitigated by granulating the comp through window screen before pressing. Doing this will help more evenly distribute the moisture throughout the comp.

[dynomike1]

ok thanks

[3inchshell]

Hello,

i have a question about stars to,

i made Chrysanthemum 8 +15% ti sponge.

 

i made them wet with 50/50 water/white spirit

 

i didnt make them to wet, after that i pressed them in a 12mm starplate with a mallet(if thats what you call the rubber hammer)

and how long would be the minimum drying time?

[nater]

Minimum? With ideal conditions, a few days. Charcoal stars can take much longer than that though.

[3inchshell]

Minimum? With ideal conditions, a few days. Charcoal stars can take much longer than that though.

 

Okay well ive taken a look at them the outside looks pretty dry to me and the smell of the white spirit is partly gone,

And if let one like fall into the container it sounds alot harder then yesterday

 

But for sure im just gonna wait a another day before i try it

[nater]

One way you can check is to put them in a sealed zip lock bag and stick it in the Sun for a few hours. If you get condensation on the inside of the bag, they are not dry yet.

[Algenco]

patience, it will take several days, possibly a week