Definitely don't put ceramic blanket around the outside of the barrel. That would probably overheat the barrel and cause it to fail. I would be concerned about setting the evaporator directly on the asphalt. Maybe you could get large (12 -16 inch square) patio pavers and put under the evaporator to make a temporary floor on the asphalt driveway. I also wouldn't set the evaporator on a skid or pallet as it will probably char the wood.
Leader 1/2 pint - Kawasaki Mule - Smoky Lake Filter Bottler
24 GPH RO, 2 1/2 x 40 NF3 (NF270), 140 GPH (Brass with no relief valve ) ProCon pump
2013 - 44 taps - 16 gallons syrup, 2014 - 109 taps - 26 gallons syrup
2015 - 71 taps - 13.5 gallons syrup, 2016 - 125 taps - 24.25 gallons syrup
2017 - 129 taps - 17.5 gallons syrup, 2018 - 128 taps- 18 gallons syrup
2019 -130 taps - 18.5 gallons syrup, 2020 ~125 taps-19.75 gallons syrup