# What can be a harmless electrolytic additive for water for creating an oxy-hydrogen flame?

I was thinking of preparing a tiny oxy-hydrogen flame for soldering. I am going to use 6V DC and aluminum sheet as the electrode for this. Now, I have to add some electrolyte to water, that can be a salt, base or acid. But, if I add $\ce{NaCl}$ or $\ce{HCl}$, they will produce chlorine. If I add $\ce{NaOH}$, it will eat electrodes. Adding $\ce{H2SO4}$ may produce poisonous gases like $\ce{SO2}$ and $\ce{H2S}$. So, what can be a harmless/least harmful electrolyte for such purpose? Is $\ce{Na2CO3}$ a good choice?

• More importantly, this is a very bad way to create a flame. It will require far more effort than just buying a butane or propane torch. – matt_black Mar 7 '17 at 16:42
• @matt_black Obviously butane or propane torch are good ways, probably the best. But, I was just thinking of creating a flame myself or at least trying to do so. – Dwiparna Datta Mar 7 '17 at 17:32

A commonly used electrolyte / electrode combination is $\ce{KOH}$ or $\ce{Na2CO3}$ with stainless steel electrodes. I believe this would be pretty corrosive toward aluminum, but stainless steel for such a setup should be cheap and easy to come by.