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which-dextrin,rg,cmc


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Posted
the more I read the more confusing it gets ?? So here it goes. FOR good BP. I Got a good ball mill. Do I mill with dextrin and granulate with h20. No dextrin and add Red Gum after milling and granulate with Alcohol (denatured) and water. Or try that CMC stuff. Seems to be a lot of different conflicting opinions out here. ?? Remember I'm a newbie here!!!:blink:
Posted

if you have dextrin use dextrin I recommend against using redgum its a poor binder and using an appropriate solvent for it adds to the price adding water to the redgum solvent will make it not work. CMC and SGRS are good too but less easy to make at home

 

you cant use H20 as far as I know it doesn't exist try good old water (H2O (not0) )

Posted
OR, you can leave out the binders, wet with water and press the BP.
Posted (edited)

I am a big fan of using *(DihydrogenMonoxide) DMHO for my BP along with a splash of C3H8O as a whetting agent.

 

Depending on what you are using the BP for, you may or may not need a binder. If you are pressing pucks, no binder is needed and also if you are pressing rocket motors from it, no binder is needed. Ifyou are however making pulverone then you will want no less then 2% dextrin added to make solid grains of BP.

 

*Just trying to act like I am smarter then Ralph's posting. laugh2.gif

 

-dag

Edited by dagabu
Posted

Dag, if you're trying to look smarter than Ralph, it helps to specify which C3H8O you mean as there are three possibilities. n-propanol, 2-propanol, and ethyl methyl ether.

 

As far as the topic at hand. I find adding dextrin to the BP mix in the mill, and wetting afterwards with water to be the easiest method. SGRS and CMC are a bit trickier to get the mix just right I have found. I don't like the red gum/alcohol thing at all. Following Bonny's solution is also extremely easy if you have the set up.

Posted

Dag, if you're trying to look smarter than Ralph, it helps to specify which C3H8O you mean as there are three possibilities. n-propanol, 2-propanol, and ethyl methyl ether.

 

As far as the topic at hand. I find adding dextrin to the BP mix in the mill, and wetting afterwards with water to be the easiest method. SGRS and CMC are a bit trickier to get the mix just right I have found. I don't like the red gum/alcohol thing at all. Following Bonny's solution is also extremely easy if you have the set up.

 

LOL! I was actually just being a smarty-pants, I had to gOOgle it ;)

 

-dag

Posted

I've had some success with BP +Dextrin that was granulated with boiling water. Seems to make it hotter.

 

Sorry, bad pun :whistle:

Posted

I've had some success with BP +Dextrin that was granulated with boiling water. Seems to make it hotter.

Sorry, bad pun :whistle:

 

That was more like 2/3 of a pun, PU :lol:!!! (Sorry, couldn't resist ;) :D)

 

WSM B)

Posted
The biggest variable in making good BP is the type of wood used for charcoal and the optimal milling method. Commercial airfloat will only get you so far. In my trial and error the dextrin (1-3% milled in) and hot water seems to make the most durable grains. I granulate through a 4 mesh screen then spread it out to dry for maybe 10-20 mins. While it is still slightly damp I pass it through a 10 screen then spread and dry completely. After everything is dry and crispy I screen it through a 20 mesh to get approximate 4FA granules. The fines I regran. or use for primer. Hope this helps
Posted

Kind of crude and condescending to point out someones simple and obvious typo??? Insulting too!! All these forums would be a lot more popular if a person would not have to take this insulting remarks.

 

 

 

 

if you have dextrin use dextrin I recommend against using redgum its a poor binder and using an appropriate solvent for it adds to the price adding water to the redgum solvent will make it not work. CMC and SGRS are good too but less easy to make at home

 

you cant use H20 as far as I know it doesn't exist try good old water (H2O (not0) )

Posted

Kind of crude and condescending to point out someones simple and obvious typo??? Insulting too!! All these forums would be a lot more popular if a person would not have to take this insulting remarks.

 

The thin of skin are always easy to hurt the feelings of. I am sure that if you dont pay any attention to Ralph's corrections and just enjoy the conversation about pyro, you will be fine.

 

-dag

Posted

Kind of crude and condescending to point out someones simple and obvious typo??? Insulting too!! All these forums would be a lot more popular if a person would not have to take this insulting remarks.

 

Sorry dude just trying to have alittle fun with a dash of my crude humour.

Posted
Have any of you guys to make your own Dextrin ? I looked for a thread, but couldn't find one on the subject. I tried once with a modified corn starch no catalyst, but it wasn't quite as hard as the stuff you buy.
Posted

Have any of you guys to make your own Dextrin ? I looked for a thread, but couldn't find one on the subject. I tried once with a modified corn starch no catalyst, but it wasn't quite as hard as the stuff you buy.

 

Lots of it, ARGO corn starch in a rectangular cake pan, 250°F and stir every few minutes. It is done when it turns a very light yellow.

 

I suggest that you purchase it from Phil's General Store, it's much better in quality.

 

 

Here is the LINK you are looking for.

 

-dag

Posted
What types of catalysts do commercial dextrin use? I saw the thread on Boric acid. Is that what works best or is there something else I could try?
Posted
I think a lot of the commercial stuff uses HCl. I swear I've seen patents about using boric acid, but I haven't been able to find them again. If you want more info, there are a lot of patents on this process. The big problem is that a lot of the catalysts will make noxious fumes and potentially harm the oven they're used in. If you have a second oven that you don't use for cooking, it may be easier to recreate some of the commercial stuff.
Posted

Hi,

does anyone of you guys has used white dextrin before?

I've read about it in another thread where it has been described as a weaker binder than yellowish dextrin because of its solubility.

I bought it from a dutch model rocket website and it has really weak adhesive abilities (even 8% in charcoal star compositions is not enough!) and only makes stiff blackmatch with over 10%.

I'd like to know if there is a major difference between white and yellow from your theoretical knowledge and practical experience.

 

-Zir

Posted
I've never used it, but I've been told it works to some degree for sparklers where a thicker suspension is preferable. Given what I've read, I get the impression that it's hydrolyzed at a lower temperature and is less soluble in water. I would have assumed that the sparkler use may have made it acceptable in blackmatch, but requiring 10% seems like too much. I'm sorry to tell you that it's just not quite as useful as the yellow variety.
  • 1 month later...
Posted (edited)

Speaking of water soluble binders: I have had problems with my SGRS, which is a pity, since I have almost 2 kgs and was thinking of using SGRS only instead of dextrin in the future.

 

Now I have found out what was wrong: there shouldn't be a single drop of alcohol in it. The last time I tried I had something like <5% alcohol just to break the surface tension, but even that seems to much. But with pure, cold water it works excellent.

Edited by Potassiumchlorate
Posted
Also SGRS is a water hog, it may require double the amount of water as Dextrin but the odd thing is even with the extra water comps using SGRS dry faster
Posted
I have a few stars drying right now. They are still soft, but I know the SGRS is good. When putting a tablespoon of it in cold water, it becomes a "jelly" within few seconds.
  • 4 weeks later...
Posted

I still have problems with my SGRS. I'm making my first TT stars, pumped, but it seems hard to get the amount of water right.

 

I also take back my statement that you shouldn't use any alcohol; a small amount is needed to get rid of the surface tension of the water.

 

I use SGRS since it's both stronger and more resistant to moisture once dried than dextrin is, but I'm still not experienced enough with it.

 

Any suggestions how to use the exact amount of water?

Posted
Could anyone please suggest a way to estimate the right amount of water? The composition gets thoroughly incorporated (moist mix burns better than dry powder), but it's either too loose or too dry for adhering. :unsure:
Posted

Could anyone please suggest a way to estimate the right amount of water? The composition gets thoroughly incorporated (moist mix burns better than dry powder), but it's either too loose or too dry for adhering. :unsure:

 

 

for pumped tt i use 5% and hammer hard, use a syringe or a spray bottle to add water, mix in a bag until desired moisture is reached then try to pump one if you get water coming out of the bottom of the pump it is too wet, simply screen the comp spreading it out evenly and weigh it evry so often until it is dry enough to work with the finished stars should look shiny, i couldnt estimate with your comp as ive never used the binder but a 1" comet with the right amount of water [dextrin bound] has dried for me in two days.

 

a few trys an error and you'll have it

 

dan.

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