We were recently asked the following question from a previous customer:

Have a repair question please: I purchased pre-finished Andiroba retro treads from Stair-Treads.com about 10 years ago and we've been very happy with your product. However, due to years of abuse by teenage boys, several of the treads at the bottom of the stairs are looking dull and scratched. Do you have any recommendations on how to restore (at least partially) their original look and finish? Recall Andiroba is not stained before sealing (?), so maybe just a coat of polyurethane would fade scratches and restore luster? Don't want to start experimenting and make the situation worse... Thanks for any advise you can provide! - Brad

First of all, we're happy to hear your pleased with your treads, and after this long, all they need is a little freshening up! If you want to actually put a light finish over top of the UV coating, you'll need to use something rated for already finished surfaces and the only product we recommend is "Traffic" from Bona-Kemi (https://www.bona.com/en-US/Bona-Professional/Products/Coatings/Waterborne-Finishes-and-Sealers/Bona-Traffic/ ). You'll want to follow Bona's directions for application but it's most likely going to involve a very light scuff-sanding and then you can apply the new coating over top of our old finish.

Since your treads are finished clear, you can do a light scuff-sanding and not worry about sanding through the finish because there is no stain on your treads, it's just a clear coat and any coloring is the natural coloring of the wood itself.

If you don't want to actually finish the treads, a good deep cleaning with the Bona Kemi hardwood cleaner may bring some of the luster back but it won't fix gouges, etc.

This same product can safely be used to coat over stained treads so long as any scuff sanding you do doesn't penetrate the original finish. The idea is not to sand into the raw white-wood and only provide a scuffed surface for the new coating to adhere.

If you do sand through the finish, order a pint of stain to recoat any exposed wood and then apply Bona Traffic.
See: Matching stain