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Star Plate Safety - Chemical Safety


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The title may be a bit misleading but is applicable.

How do you "neutralize" a star plate from one usage to another if there is the possibility of chemical reaction issues?

For example, I am interested in using a small star plate with an Ammonium Perchlorate formula.  How would I "clean" it after use so that if I used a nitrate mix next there would be no reaction?  The opposite question holds true as well:  If I used the plate with a nitrate formula, how would I neutralize it for safe use with AP?

And one other...I have yet to make any chlorate stars, but same question.  If I used an AP mix in the plate and wanted in the future to use a chlorate mix, how would I neutralize?  (and vice versa)

I know the correct answer is "don't use chlorates" or "don't make chlorate stars - perchlorate formulas are as good and safer."  I intend to heed that advice but am still curious how one would completely clean a plate, pins, etc, as possible and practical.



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I do not see the problem?

You clean it of course, with a suitable solvent if there is build up of non water soluble deposits. Why would your cleaning be incomplete?

But, when it comes to the worst incompatible combination, ammonium perchlorate and chlorates, you should not even use those chemicals in the same room!

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an abundance of caution...  I am paranoid about the safety aspects / incompatibilites of chemicals and unexpected / unintended consequences.  

I think the worst that would happen with ammonium perchlorate and nitrates is water, but still I want to avoid it.


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Posted (edited)

While I am thinking about it...is there a way to slow down the evaporation rate / drying rate of denatured alcohol?

The comp I am considering uses PVB as a binder and denatured alcohol as a solvent. If I were to use it in a star plate, I fear it would dry quickly and I would not get a good press (thinking 1500 psi on the comp) and have wonky cores as a result.

I imagine screen mixing in the denatured alcohol through a 20 mesh screen to distribute the alcohol evenly, and then putting that dampened comp in the star plate.  

What got me thinking of this is...I believe MEK evaporates more slowly than Acetone and can be used interchangeably for binders that need acetone as a solvent.  Is there anything similar for alcohol?  Or would MEK be a suitable solvent for PVB?  A quick online search suggests MEK is a good solvent for PVB...

I suppose I could make the comp into patties and press through a 5 mesh screen and roll, but I still could run into the issue of the alcohol drying out too quickly before I get the patties pressed through completely.

Thank you.

Edited by nordicwolf
updated info
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I still do not understand the cleaning problem? Always use hot water and soap before and after you used AP on your equipment. Polish afterwards with suitable solvent and rags/brushes. 

MEK should work with PVB.

Keep your moist composition in a plastic bag. The exposure during loading of the star plate should take less than a minute so no harmful evaporation before pressing should be possible. Collect the excess with a brush and transfer back to the plastic bag before pressing. 

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I agree with everything Crazy Swede said.  Relevant solvent (if not water) to get rid of most of the residue, and hot soapy water.  A bottle brush or other appropriately sized brush can be helpful in cleaning out the cavities in the plate or between pins.  Most of the oxidizers in question, which consists of basically all the potassium oxidizer possibilities and AP, are fairly soluble in hot water.  You shouldn't have any issues with being able to fully decontaminate them.

On tools with a lot more nooks and crannies and areas material can get lodged or are harder to clean, I feel better personally about having separate sets for AP specifically.  This mainly applies to screens for me but also potentially ball mills.  

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