Difference in spar urethane & polyurethane

[victoriasecret]

I've taken in this project around my area and I'll need to do the outdoor wooden beams and stained wood ceilings. I'm thinking I can use spar urethane for UV protection of the exterior rather than just the regular polyurethane? I'm thinking I can do this inside as well, but I have not used it before to be honest so I was wondering if I might need a different technique rather than when I'm just using polyurethane? What's the finish for this spar one?

 

[Bumble_bee]

If you're using spar urethane, it's a great choice for outdoor wood since it's made for uv protection and is more durable against weather, well.... for indoor use, it's fine too, but it might not give you the same smooth finish as regular polyurethane. The finish can be a bit glossier, which is something to keep in mind, it's typically brushed on, but you may want to sand between coats for a smooth result.

 

[squeezycheese]

If you're using spar urethane, it's a great choice for outdoor wood since it's made for uv protection and is more durable against weather, well.... for indoor use, it's fine too, but it might not give you the same smooth finish as regular polyurethane. The finish can be a bit glossier, which is something to keep in mind, it's typically brushed on, but you may want to sand between coats for a smooth result.

Thanks for this! didn't know that spar urethane is better for outdoor wood. learning so much here as a newbie

 

[Marcella]

I've taken in this project around my area and I'll need to do the outdoor wooden beams and stained wood ceilings. I'm thinking I can use spar urethane for UV protection of the exterior rather than just the regular polyurethane? I'm thinking I can do this inside as well, but I have not used it before to be honest so I was wondering if I might need a different technique rather than when I'm just using polyurethane? What's the finish for this spar one?

Spar urethane is better for outdoors than regular polyurethane! Agree that it's best for UV protection and moisture resistance. I don't recommend it for inside use since the fumes are bad bad for you. Unless it's an open indoor area, it's not gonna be much.

 

[j0hn-th0ugh]

Folks have hit on some good points here about spar urethane being topnotch for outdoor wood like your beams and that extra UV protection is a big deal. I used it on my porch swing and it held up great. But for indoors like your ceilings, the replies about fumes and a potentially softer or glossier finish are worth heeding. I usually stick to interior-specific polyurethane for that kind of job to get a harder crystal clear coat.