Bucket Insulation



I've used corrugated cardboard cut from a box and wrapped around containers for insulation.  Since the paint buckets I use are not cylinders but truncated cones a rectangle of cardboard is not going to fit well.  Try rolling the bucket over the cardboard and marking the curves the top and bottom are following, cut this out and see if it approximates the shape needed. Then use it as a pattern to cut more pieces.  Trying to cut a full wrap in a single piece is difficult  and not worth my effort, using two or more pieces and overlapping and staggering the seams on successive layers worked well.  I applied 3 or 4 layers using duct tape to hold them in place. The I painted it white and covered it with cellophane wrap for waterproofing.  This is lite weight and lasted for several seasons.  I've not tried bubble wrap but seems like it would work also but would need some help being opaque.  

​How to insulate the exterior of a plastic bucket using spray foam insulation:
Note:
The stuff sticks to everything including skin and clothes and won't come off . The solvent fumes are not good for you and can't be good for plants.  Don't use on or near already potted plants.    It is easily carved with a knife once cured and is rigid, durable, waterproof and paint-able.

Remove the bail, it won't be of much use after the foam is applied. 
Invert the bucket on an old board or other flat surface that you don't care about, out of doors. Hold the bucket down and spray a bead around the "top" of the bucket to secure it to the board. Wait a few minutes for the foam to expand.  Cover the remaining exterior of the bucket with beads spaced about an inch apart including the bottom of the bucket.  Don't worry about making it look good, because it won't, the stuff is lumpy and ugly. A few small voids are acceptable.   Let the foam expand for a few minutes and then apply a second coat, applying the beads to the voids and seams of the first coat. Apply a third coat if you wish. Let this cure for a day.  Inverting the can and spraying into a trashcan can help clear the unset foam from the nozzle and may let you use the can again. I did five buckets at a time and when done went around the house and sealed up cracks and such in the siding. I let it cure overnight. Then use an old kitchen knife or hacksaw blade to level the bottom of the bucket.  Cut around the top to release it from the board. The cured foam is translucent so next paint it black to make it opaque, followed by white to reflect the light and heat.