I have some new walnut veneer furniture products and want to apply a high quality finish. I知 looking for the best looking finish, yet something that is reasonably durable and reasonable to maintain. People have suggested a sprayed waterborne or polyurethane, or a tung oil finish. The sprayed finish guys told me the veneer would not take the oil well; due to its thinness (.025 inch), the oil would not be able to penetrate correctly. Is this true?
From contributor C:
Well... the spray guys are correct as far how much is there, and the amount left for the unglued thickness to be able to absorb the oil, but even if that amount is only half the current thickness - it will allow the oil to penetrate.
That said - the protection of the oil is a matter of chemistry, not how far it penetrates. The properties of tung will be evident even if applied to a piece of glass.
What would concern me much more is future repair of the oil surface. If a cigarette burn were to happen, there is little room to sand out the damage and apply more oil without the possibility of sanding through the walnut veneer.
On the other hand, the same could be said for a surface coating of any other material receiving the same type of damage, unless a very thick coating that would minimize damage to the veneer itself.
So it's really a matter of which you think looks best and will provide ease of repair. My vote would be a 2k urethane, but if you know for sure that damage will not occur, then tung is a viable option. Be sure you use a polymerized tung, though, for best overall performance.
Another choice is to use a very low sheen lacquer or other coating to give a simulated oiled look. It is very thin, just 2 coats sanded in between, so it's close to the wood like a built-up oil finish would appear.
No matter which way you go, keep in mind that any finish can be damaged, and let your clients know how to care for the finish, and don't give performance guarantees of any kind. You can't be responsible for their carelessness or abuse. There are no bulletproof finishes.