Best way to insulate keggle

[nate456789]

Am looking for ideas on insulating my mash tun that is made from a 15 gal keg.
I have some of the reflective bubble wrap used to build my shop. I have seen people use that.
Is there a better way to hold the heat in?
Thanks

 

[FirstStateBrewer]

I wrapped mine with reflective bubble wrap, but it melted a little around the bottom after applying fire to heat the mash.

 

[HDIr0n]

I used the bubble wrap, with a couple wraps of fiberglass insulation made for water heaters.

-G