Yes you're not using enough catalyst probably or not warm enough. It should say on resin can how many drops to use. I usually use 12 drops per ounce of resin. Abrant has good tutorials on resin in his YouTube videos.
resin varies by size and person. If you're new to resin I would get a small starter kit to try it out first. start with a small piece like arm or shoulder then work your way to the helmet because you don't want to mess that up since its the essential piece to your armor. Walmart has a good...