Use some of the time while the interior is drying and attach the feet.
Cup holders built into the lid of the cooler will save time, hassle and money.
2" inside diameter PVC pipe, like couplings, will fit perfectly inside the cup holders to make the feet. For this step in the the project, use the fast-drying marine grade flexible sealant.
Apply a thick layer of the permanent bond, flexible sealant in the bottom of one of the cup holder.
Insert one of the 2" inside diameter PVC pipes into the cup holder at a slight angle.
Apply sealant along the base of the pipe while you rotate the pipe into the cup holder. Continue rotating and applying sealant until: - You have created a nice strong bond between the cooler and the PVC pipe; AND - The end of the pipe is flush with the bottom of the cup holder and the pipe is perpendicular to the cooler.
Move onto the next cup holder until all four (4) feet are finished.
Continue to let the shelter Air Dry for the remainder of the 24 hours from step 5 before turning it over.