Hey guys let see if you can help me, I am trying to skinned a product, with carbon firbre, I was told to add catalyst to epoxy. Do this really needed? what is the sense of adding catalyst to epoxy if the epoxy is a laminar glue

Iam not one for giving advice,but I would suggest some people read the basics of understanding epoxys and polyester resins and the difference in the way they work regarding catalyst mixing,shrinkage rates and applications,I think before using carbon and the cost of the materials,I would recommend a book from blue gee,most off it is basic but very understanding for a novice.