I am wanting to restain my spa cabinet that I believe is made out of cedar wood but has the look of redwood. I'm unsure what type of stain to buy since most of the stains I've looked at are for interior use. Do I need to prime also? I've heard the Cabot's line of stain is good for this purpose but again I'm unsure what to buy. If someone could lead me in the right direction of what to use I would appreciate it.