I've had a Coleman 16' scanoe that I bought new in 1980. It's still a good boat,and I use it regularly ,but I have troubles with patches staying put. I've tried the recommended method of heating to treat the "Ram X" plastic to accept Epoxy,but have only had limited success. Have any of you ever found a sure-fire method of fixing leaks in these canoes? Thanks for any input.. God Bless