What is spar urethane vs varnish. Its the go to material for any exterior woodwork that needs a clear finish but because its high resin content gives it a yellowish hue it isnt the best choice for interior furniture. Polyurethane can be a difficult debate but polyurethane typically wins when it comes to indoor applications. Polyurethane finish features a few downsides because it cures sets and rises more slowly than spar urethane that could dry in a matter of minutes. Youll find it in just about every big box and local hardware store.
Spar urethane tends to have more oil mixed with it. From a technical stand point theres a huge difference between marine spar urethane and spar varnish. Urethanes are harder glossier and more durable especially if a true lpu. Spar urethane of which minwax helmsman is a leading brand is spar varnish that includes urethane plastic as one of its resins.
While the latter is more concentrated and is limited because of the same the former is more conventional in nature and can be used more extensively. The main difference between the two is spar varnish will eventually chip or chalk off over time while spar urethane will maintain a hard shiny surface. Therefore it is also called long oil varnish. This spar urethane is probably the most readily available spar urethane on the market today.
Spar varnish and spar urethane are two very different compounds. They are also hard to apply well especially if a wr lpu and can often be too hard and brittle for some hardwoods as brians experiences suggested. Due to a large amount of oil on spar urethane it tends to be softer and pliable unlike polyurethane which is hard and stiff due to the lesser amount of oil in its mixture. Have been reading about spar urethane and spar varnish and dont know which way to go.
It sounds like a good quality varnish might be a better way to go. Studying spar varnish vs spar urethane the differences we come to the conclusion that both these components are used for similar reasons. Sounds like there are also some better products out there than the helmsman spar urethane. Obviously epifanes is too exspensive for such a large area.