Haven't used that product but have used JB Weld-reinforced fibreglass tape a couple of times with great success. Started with a 'temporary'
repair of the broken nipple that connects the
exhaust manifold to the riser while sitting several miles off the entrance to Moreton Bay in
Australia. It worked so well that it is still there years later. Also fixed a split in the housing for the fresh
water pump on the mighty
Westerbeke (part was not available and was told that cast iron does not weld well). Easy to do if a bit messy. Glop on the JB Weld and then wrap with f/g tape, then cover over with more JBW, Then
paint if you are into the niceties.