I would HIGHLY suggest simply overlaying Detonation Film's stock footage onto your raw video, and you're done.
To composite this on, you need to either add it in your NLE (non-linear editor such as Adobe Premiere, Avid, Pinnacle, or Vegas) or in an effects compositing program such as EffectsLabDV
If you have an editing program that can do chroma or color difference keys with multiple video tracks, tht would be the free approach. Otherwise, it'd be up to you to purchase EffectsLab, which, in my opinion, is well worth it
, especially considering the affordable price.
The only other option I can think off would be to actually make a real, physical explosion, and, in light of recent posts and ideas, I think I can guide you to a safe way to do this.First off, there is a product called ThunderpipeFX which is essentially a debris dispension system that can make explosions depending upon what you insert into it.
More information and discussion about it among FXHome members can be found hereThere is also a trick that involves igniting coffee creamer, which, luckily enough, is only flammable when airborne.
I think for the effect that you're going for, this would work well. Information, discussion, and how-to's found here
.If you feel either of the two latter effects listed are too hazardous, keep in mind you could always do them at night whilst recording, and use that footage in the first suggestion instead of Detonation Film's stock footage.
Well, that should wrap up the options I have to offer. Good luck with your effect.