Merlin Posted October 27, 2015 Posted October 27, 2015 I am using the following formula but dont have a lot of experience pumping. Strontium Nitrate-53Mg/Al -19Parlon - 17red gum- 5charcoal -5Sulfur -5Dextrin -5 I screened in all except the mg/al and mixed that in last.I added 8% distilled water to dampen and worked it up. I have not primed yet. My question is this. I am using a Wolter 1/2 inch star plate but do not have a mechanical press and I do not want to hammer on this expensive star plate. I simply stand on it (260 lbs) for a minute.Am I doing this right? The stars seemed a little delicate when ejected though most held together for drying.
frederick Posted October 28, 2015 Posted October 28, 2015 If this is the 49 pin plate he sells then are you doing nothing more than packing it slightly, which accounts for why they are barely holding together. You need several tons of force to properly press a large plate of stars. Check out that video from Ned. You can get a better idea on whats needed if you follow along with his math and adjust to your pin area.
Carbon796 Posted October 28, 2015 Posted October 28, 2015 (edited) The Mg/Al could have been screened in at the same time. Saving you a step, unless it was too coarse for your screen. By just stepping on it your only applying about 27psi on the comp. You are going to need a press, to effectively use that star plate. Hammering on it, will likely not be much more effective. Just out of curiosity, what is the name of that formula, or source ? It looks like a incorrectly copied version of PGI Red. Edited October 28, 2015 by Carbon796
Merlin Posted October 28, 2015 Author Posted October 28, 2015 If this is the 49 pin plate he sells then are you doing nothing more than packing it slightly, which accounts for why they are barely holding together. You need several tons of force to properly press a large plate of stars. Check out that video from Ned. You can get a better idea on whats needed if you follow along with his math and adjust to your pin area. Well you are correct I am not using near enough pressure. I have nothing so elaborate as a hydraulic press. I will try to think of something less I have blown $300+ on a useless starplate!
Merlin Posted October 28, 2015 Author Posted October 28, 2015 The Mg/Al could have been screened in at the same time. Saving you a step, unless it was too coarse for your screen. By just stepping on it your only applying about 27psi on the comp. You are going to need a press, to effectively use that star plate. Hammering on it, will likely not be much more effective. Just out of curiosity, what is the name of that formula, or source ? It looks like a incorrectly copied version of PGI Red.Kyle Keply from Passfire is where I got the formula. But a hydraulic press is out of the question for me. I may have an expensive paper weight.
frederick Posted October 28, 2015 Posted October 28, 2015 (edited) I don't know what your budget is but there are several versions, manual and electric over hydro, available on ebay and amazon. The cheap versions are in the $140 ish range shipped. I should add I've seen several reports that those cheap versions tend to need some welding to work optimally but they would get you started. Edited October 28, 2015 by frederick
deepdixie Posted October 29, 2015 Posted October 29, 2015 Kyle Keply from Passfire is where I got the formula. But a hydraulic press is out of the question for me. I may have an expensive paper weight. Why not purchase a 40 ton Hydraulic bottle jack from Harbor Freight or a local Farm Supply Store? They can be had for around $40 or so. Some slight steel fabrication may be required to build a frame but you might be amazed at how cheaply a decent press could be contructed, with a bottle jack and some scrap metal.
Merlin Posted October 29, 2015 Author Posted October 29, 2015 I may try that if I can find someone with a welder and some design know how. I am a idiot without instructions when it comes to mechanical things which is why I have respect for people that can mill things like tooling in their shops.
psypuls Posted October 29, 2015 Posted October 29, 2015 press it with your fingers and hands on the plate
Merlin Posted October 29, 2015 Author Posted October 29, 2015 (edited) press it with your fingers and hands on the plateI am not able to apply several tons of pressure with my hands Edited October 29, 2015 by Merlin
frederick Posted October 29, 2015 Posted October 29, 2015 Unless you have a good machinist friend who will do this work for free, and also friend who can and is willing to weld for free, you will spend more money, time, gas, etc., in your effort to build a simple press. Even with the above labor donated, the cost of steel, the jack, weld materials, the paint, and nuts bolts pins springs, will most likely suck any savings you think you might gain from your pocketbook. (and don't forget the case of beer you should be donating to the welder and the machinist who are working for free)
Merlin Posted October 29, 2015 Author Posted October 29, 2015 I bit the dust and got a press for$200 that should work. Strange though I was watching a video of John Werner make 3/8 stars using a plastic skylighter plate and he only used hand pressure. 1
Peret Posted October 31, 2015 Posted October 31, 2015 Use some timber to spread the load, and dwell for a few seconds to let it consolidate. Yes the stars are fragile when they come out of the plate, but when they're dry they will clink. A tip for pumping - don't make the mixture very wet. It should be like damp sand, not as wet as you need it for cutting. When you squeeze a lump in your hand it barely holds together. As you add water there comes a stage where you start to feel resistance when you stir it with your hand, and that's getting close. Push the damp comp through a 10 mesh screen, then it will be relatively free flowing and you can shake it into the plate and shake off the surplus. Put the base of the star plate on a piece of plywood, then fill it over the bowl of comp and shake it off straight back into the bowl - saves a lot of mess - and press onto the plywood. I pump at 100psi on the stars, which with my cheap little Starlighter Chinese star plate is only 200 pounds applied. Since I happen to weigh about 200 pounds I just press with my body weight until my feet nearly come off the floor. Your star plate will start to seize up after about 20-30 cycles, as you get a buildup of dried comp in the holes. Mine gets so bad I've had to separate it with a pry bar. Stop and wash it and use a wire brush from your gun cleaning kit to clean it out, and whatever you do, never ever try to pump red gum/alcohol or parlon/acetone based stars. The only way to clean that crap off is to burn it off.
Merlin Posted October 31, 2015 Author Posted October 31, 2015 (edited) Thanks for the replies. In the end I got a 20 ton shop press to use with the Wolter plate. Mr Wolter made top and bottom aluminum aluminum plates for the star plate and a couple bars for extraction.Hoping the wife won't notice! Right. I also use a couple small Chinese plates. I cut 2x6 wood for top and bottom. Going to try using Arbor to press if not enough pressure I will stand on them. Last year I used a rubber mallet. I plan to bind with SGRS. I usually spray the studs on the small plates with Pam to help ejection. Again thanks for the info. Edited October 31, 2015 by Merlin
MrB Posted November 2, 2015 Posted November 2, 2015 A tip for pumping - don't make the mixture very wet. It should be like damp sand, not as wet as you need it for cutting.Purely speculation, but... IF you wet it as much as when you cut stars, shouldn't they consolidate better with less pressure?It would become a horrible mess to work with, sticking to everything, not wanting to keep it's shape and so on, but...? I don't suggest doing it this way, just use a proper press, it saves time, and money, in the long run.B!
Mumbles Posted November 2, 2015 Posted November 2, 2015 That is actually true MrB. You still want to keep them drier than when cutting though. Even hand pressure can eventually do it. Too wet and the comets start to droop and deform, which ruins any possibility for stacking or rings in a shell. I will often take excess scraps from cutting streamers and glitters, and pump a few comets from them for rising tails. They're ugly and lumpy, but are usually able to be pasted or taped on the sides, and attached to a shell.
MrB Posted November 2, 2015 Posted November 2, 2015 Thanks for confirming. I still pretty much only roll stars, so i have no experience with either. I have a few comet pumps, and i really need to get me one of those specialty pumps that made quarter segments, but nothing that gives me any experience with trying to work out working chunks from lower pressure.B!
Peret Posted November 3, 2015 Posted November 3, 2015 Purely speculation, but... IF you wet it as much as when you cut stars, shouldn't they consolidate better with less pressure? What happened to me when I over-wet pumped stars is that under quite modest pressure, the pins went all the way down as the mixture flowed out the bottom of the holes. Now I use less and less water. I did a batch last week that were so dry, I thought I was going to have to crush them and pump them over again, but now they've dried out properly they're hard as stone.
Maserface Posted November 3, 2015 Posted November 3, 2015 I've heard that some commercial manufactures press with as low as 3% moisture. They obviously press to much higher force than typically done, but it's possible. I personally aim for 6-7% water when pumping.
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