spar varnish

noun

a durable, weather-resistant varnish applied to unpainted wooden areas, especially on ships.
a varnish made from sulfur, rosin, and linseed oil.

Origin of spar varnish

First recorded in 1905–10

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

When linoleum begins to show wear a coat of spar-varnish or carriage varnish will restore it satisfactorily.
The Library of Work and Play: Housekeeping
Elizabeth Hale Gilman