Can I use different hardeners with ProMarine Supplies 521 Marine Epoxy?

The short answer is yes as we feature two hardeners, Slow and Fast, that mix with our Marine Grade Epoxy Resin. However, several factors need to be taken into consideration when deciding upon which hardener to use in order to get the best results. The first consideration is how much time you need to manipulate (working time) the epoxy resin into your project – as slow hardener will give you about 30 minutes – while fast setting will provide only about 12 minutes.
There are a number of other factors that will also affect epoxy resin curing time; hardener ratio, ambient temperature and the use of heating tools (heat guns and lamps) all play a part in epoxy resin’s transition from liquid to gel to solid. Epoxy resin will cure faster in a warmer than cooler environment – so in cooler conditions, using a fast hardener may be advisable – while the opposite may be warranted while working in warmer temperatures.