The flex seal stuff is very good for many applications but golf cart tires? First off, it is going to look like icing on a cake. Ok on a cake but looks like crap on a tire. I posted a few days ago about getting take offs or ordering new tires. I didn't realize how cheap you can get new tires. I got OEM replacements mounted on new rims for $35 each shipped free to my home from Walmart online. I ordered them yesterday and they will be here by Sat.. If you order from them make sure you get the tire/rim combo if that is what you want. There isn's a lot of price diff between just the tire or mounted with rim.
https://www.walmart.com/ip/43803777