[Timothy Terwilliker (OP)]

I made a batch of black powder from KNO3 and charcoal using a ratio of 80% KNO3 and 20% charcoal. I separately ground up each component in a coffee grinder and mortar and pestle then thoroughly mixed them in a cup. I set some on a tin can outside and tried holding a lighter to it but it just sparked a few times without burning. I made it based on this video however mine did not turn out like this

did I add too much or too little of each? is there anything I can do to save the batch?

[Kryptid]

Maybe you didn't grind it finely enough? Could there be excess moisture in the mixture?

Wikipedia has this to say about the proportions: https://en.wikipedia.org/wiki/Gunpowder

The current standard composition for the black powders that are manufactured by pyrotechnicians was adopted as long ago as 1780. Proportions by weight are 75% potassium nitrate (known as saltpeter or saltpetre), 15% softwood charcoal, and 10% sulfur.[94] These ratios have varied over the centuries and by country, and can be altered somewhat depending on the purpose of the powder. For instance, power grades of black powder, unsuitable for use in firearms but adequate for blasting rock in quarrying operations, are called blasting powder rather than gunpowder with standard proportions of 70% nitrate, 14% charcoal, and 16% sulfur; blasting powder may be made with the cheaper sodium nitrate substituted for potassium nitrate and proportions may be as low as 40% nitrate, 30% charcoal, and 30% sulfur.[106] In 1857, Lammot du Pont solved the main problem of using cheaper sodium nitrate formulations when he patented DuPont "B" blasting powder. After manufacturing grains from press-cake in the usual way, his process tumbled the powder with graphite dust for 12 hours. This formed a graphite coating on each grain that reduced its ability to absorb moisture.

Adding sulfur apparently helps reduce the required ignition temperature. Powdered sulfur doesn't cost very much. You should try experimenting with different proportions of the ingredients and see if it helps.

[Timothy Terwilliker (OP)]

The mix was 20 teaspoons of KNO3 and 5 tea spoons of charcoal which i ground with a mortar and pestle to an "air float" consistency its dry to the touch so i don't think its a moisture problem. I don't have access to sulfur so this was supposed to be a sulfur free mix. I think is has something to do with the ratio of KNO3 to charcoal do you think adding more of one component would help?

[alancalverd]

Try weighing your components, 70/30 w/w. The density of charcoal is not reliable, so a mix by volume is unlikely to be optimum.

[Kryptid]

I don't have access to sulfur

You can order it off of Amazon. I've done it before.