David Weaver
I know nothing about chairs, but target makes a water-based black lacquer product.

I have a can of it, but haven't used it yet.

https://www.targetcoatings.com/product/emtech-em6600-wb-raven-black-lacquer/

It may be a little bit too modern "techie" for chairs, though.

I've had good luck with the WB clear of the same family when using a crosslinking additive.