How much resin and catalyst do you use for installing FCS X-2 fin plugs? ½ oz per X-2 plug, mix ½ cc MEKP per ½ oz polyester resin: so for a tri fin (6 X-2 plugs) mix 3 oz poly resin and 1.5 cc catalyst You can download our resin chart HERE which includes info on how much resin to use for finboxes