Staining over stained boards- Is it possible to restain boards?

If the wall is indoor, you might check into general finishes gel stain. I use it to stain over finished wood furniture often and I adore this stuff. I also stained oak cabinets in a bathroom. It always be works wonders for me. I will just rough up the surface ever so slightly and wipe it on right on top of the existing finish.

https://www.amazon.com/gp/product/B001DSY50Y/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B001DSY50Y&linkCode=as2&tag=joyeliz57-20&linkId=1962004c936949458067d34f1cb86a2a

It is not possible to stain over a stain because stains are transparent. You will have to paint to cover the old colors.

Yes, you can.

Some things to consider are is there a finish coat like poly or is it just stain. If it is poly'd then you will have to sand it. If not and you can test an are, try sanding and not sanding with the stains you want to use. Remember that because there is already a "base color" you will not get a result for the color on the can. You are now blending colors and with each addition it could get darker. There are also bleaching agents available at your paint store. You paint experts at your home improvement center may be able to help you.

Applying the stain over paint will make the paint look aged and old. It can also have the effect of making the paint look like a blue stain on wood rather than normal paint. It will generally darken the piece overall. Using a coarser brush will enhance the grain effect.

Adding stains to stains will always make the result darker, like holding two pairs of sunglasses together.

Yes you can stain over stain with gel stain. You can go darker but not lighter.

https://www.minwax.com/how-to-finish-wood/change-stain-color-with-polyshades/

I'm with Joy on this one. All I use is General Finishes products. They are fantastic!

Thank you for the link!