you are wright , open cell foam . I did coat it with water proofing . and have a light color vinal that I will use , just waiting for the wife to get some time off from work to finish the job . I have stainless steel zippers & they will be coverd. Time is short I am scheduled to put her in the slip on the 25th and still have a few things left to do . hopefuly it will warm up and get dry soon
