I totally agree with Keith about the value of Japan Drier. I add a very small amount to my homemade finish. It consists of water based marine spar varnish and pure tung oil, 50/50.

When preparing to put on a coat I measure out the finish and add a very small amount of drier just before applying it. An application is always dry enough for the next one within 48 hours, thanks to the Japan Drier.

Experimentation may be necessary to get the proper amount. I measure it in drops, with an eye dropper.

May God bless America and those who defend her.