Deck Stain Application?

It's extremely difficult to strip a stain off of wood. The reason is that stain, unlike paint, actually penetrates into the pores of the wood, as opposed to staying on the surface of the lumber. So, instead of removing a finish that is onto of the wood, you would have to sand away the wood until you finally got to a point where the stain didn't penetrate so far. By then, you will probably have removed too much wood. By applying a different color stain over the redwood, you will have to deal with the color becoming something of a mixture. With the redwood having aged however, you may achieve a result closer to brown than red. But it would be hard to tell in advance. Perhaps you could test the stain in an inconspicuous spot and see what happens. If you decide you don't like the color that is created, you could always then decide to apply a surface paint over the stained lumber.

I've had to do something similar to my deck BTW.

good luck

Well, for restaining. I advise you to remove the existing stain on the surface of the deck. It will be a difficult task because all the stain penetrates into the wood, and you must remove a maximum portion of wood to remove the existing stain. You should go with color stain it would be a better option as compared to semi transparent stain.