I think everyone I've worked with in the hobby has used West Marine 105/205. Has anyone used the comparative solution from Total Boat? TotalBoat 5:1 Epoxy Resin Kit (Gallon, Fast Hardener), Marine Grade Epoxy for Fiberglass and Wood Boat Building and Repair https://a.co/1VN63Jv
I can't vouch for their epoxy, but ive used their expanding flotation foam on numerous projects to good results. For most things epoxy/foam/glass related, I use US Composites: Epoxy : Epoxy Resins and Hardeners (uscomposites.com) You can almost never beat their prices, and their quality is top notch. However with shipping and whatnot, I'd probably be tempted to try the TotalBoat.
