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Water temp with dextrin binder


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#1 BetICouldMake1

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Posted 08 August 2018 - 11:14 AM

I've seen recommendations for boiling water and room temp water as solvent. I know that KNO3 has higher solubility in warm water so is that the reason for binding with hot water or does the heat help activate the dextrin? 

 

Basically just wondering what the benefit (or potential drawbacks) of using hot vs cold water as solvent are. 

 

 

As a side note: is there a preferred way for newbies like myself to post multiple questions? I always do my best google-fu and forum search before posting, and I have started new posts rather than tack questions onto a single post since that seems like it would make it easier for other newcomers that might have similar questions to search for posts, but I also don't want to spam the boards with the 1000 questions I have. 



#2 Arthur

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Posted 08 August 2018 - 11:32 AM

Hot water can cook dextrin very quickly to a hard bound lump. Definitely the hardest stars I've made were dextrin bound with water from the kettle at coffee making temperature.  


Edited by Arthur, 08 August 2018 - 11:33 AM.


#3 pyrokid

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Posted 08 August 2018 - 02:42 PM

I've never used hot water to activate dextrin. I bet it does result in a greater activation, but I've never had any problems with room temperature water. The use of boiling water adds cost and handling concerns to your process.



#4 Mumbles

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Posted 08 August 2018 - 11:17 PM

Hot water has advantages for a couple of things.  Namely blackmatch and polverone.  On a purely comfort level, it's way more comfortable to dunk your hands into warm comp than cold comp.  Potassium nitrate is endothermic when it dissolves.  If you have ever used room temperature water to wet a nitrate based composition, you may have noticed it's cool to the touch.  

 

Hot water dissolves more nitrate, and makes it a bit more fluid.  In my opinion, this helps to penetrate cotton string better for making black match.  Plus the previously mentioned point makes kneading it a lot more pleasant,  For making polverone, it can help to dissolve some coarse nitrate and generate a bit faster material.  It also may allow you to get away with a bit less water.  The hot water makes a good wet comp, which solidifies as it cools.  The repeated regranulation if you follow Mike Swisher's or Fulcanelli's instructions gives dry material in a day or two depending on what sort of atmosphere you're working in.

 

The same theory may apply to hurt black powder.  If you use hot water it may dissolve the very fine milled nitrate to generate larger crystals as it evaporates.  

 

Personally I use room temperature water for most everything.  The two exceptions are black match (mostly for comfort), and polverone as mentioned previously.  


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#5 Maserface

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Posted 10 August 2018 - 11:09 AM

I use boiling/hot water for polverone too, I didn't once, and ended up having a much harder time.  The tepid water batch I did resulted in a larger percentage of fines, and seemed more tedious when getting the moisture level correct for granulating.



#6 BetICouldMake1

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Posted 11 August 2018 - 10:02 AM

Thanks guys. The potential recrystallization of nitrate when making bp was exactly what I was wondering about. 






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