encryptor:
I was thinking to fill with hydrogen by a foil and hydrochloric acid mix leading up to the blimp interior.
If you do this, don't fill it with hydrogen in this manner. And please don't light it off. Why?
Because what you are describing is basically a kind of poisonous gas bomb; the reaction of hydrochloric acid with aluminium basically creates hydrogen and chlorine gas via an exothermic reaction (that is, the reaction gets hot - very hot). In fact, left to its own devices, with enough aluminium and a high enough concentration of HCl, it will self-ignite. It's actually a commonly known "anarchist's cookbook" type of device (though usually done in a capped-off 2 liter bottle, with a burning candle or flare on top - nothing like burning plastic shrapnel and chlorine gas to get your blood going!).
Likely, you wouldn't poison yourself, but you might make yourself sick, eye irritation (or worse), etc - such a mix is very nasty stuff...
encryptor:
Then either by a timed delay or RC control cause an internal combustion inside the blimp to see what the end result would be.
Well - if all you had inside the gas envelope was hydrogen - absolutely nothing would happen, because you need oxygen mixed in the right amount in order for it to combust...