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Sodium- vs. potassium- or lithiumwaterglass


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Posted

Another thing that just came to my mind:
It is common practice to treat paper "nozzles" like the sidevents of hummers, stingers ect. with sodium waterglass to prevent paper erosion somewhat.

The sodium variant is the most common, most readily available - because it is the cheapest.

For the amounts we use, the price is irrelevant. So how about potassium- or lithium silicate?
Have you ever compared all the three in terms of effectiveness in fireproofing and usability?

  • 2 weeks later...
Posted

The following article might shed some light on the aspects regarding different silicate based solutions:

 

https://core.ac.uk/download/pdf/26204220.pdf

 

The potassium variety might be usable pretty much similar to the more common sodium silicate, but lithium forms an insoluble compound. As it turns out it is still possible to produce a colloidal form of the Li variety that remains in solution...

  • 3 months later...
Posted

Interesting would be a comparison in heat resistance, but I havent found such information nowhere.

 

Anyway:

A bottle of lithium waterglass is ready for action.

 

If anybody has some opinions on how a comparison with the sodium variant should idially be executed, please let me know...

Focus is on typical pyro problems, papernozzles of stingers, hummers and such...

My approach would be to press BP in tubes, drill holes and treat them, check out the erosion.

 

Since additives tend to worsen the problem, repeating the test with Ti and coloured compositions comes to mind...

  • 1 year later...
Posted

Meanwhile I made a comparison.

My conclusion is that (at least in my test setups) waterglass does not help at all.

I compared 10mm ID tubes with 2mm sidevents, with whistlemix and good BP, with sodium-, lithium- and without waterglass.
When used, the waterglass was applied generously so it could soak into the holes.

In each case, the tubes treated with wasterglass had identical erosion than those without.

Do you have an opinion on that?
Have you guys ever determined any advantage from waterglass?

Posted (edited)

I treat my cardboard mortar tubes with it. And, I’m trying it to prevent case burn thru on model rocket motors. Seems to help there. I don’t think one could get enough concentration for the hellfire of a nozzle to make much difference.

Edited by Richtee
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