Anyone with experience with water based spar urethane?

[Mackenzie Robens]

Has anyone sprayed water based spar urethane? Does it perform well? I have a lot of small pieces to finish, some will be outside so want to use a spar, but hoping to spray = water based. Any info or experience would be great! Thank you!

[Tom M King]

Why do small pieces need spar? I would think Marine would be fine. I've not even heard of a water borne spar varnish, but I've never looked for any.

[Jerry Bruette]

Varathane makes a water based spar. I used it on my replacement windows and trim. Brushed on the windows and sprayed the trim. It was a little different to work with. It was thicker and it dries different than regular water based poly. You'll think it's not curing because it stayed soft for a longer time.

[Jim Becker]

It would be interesting to me how there could be a "waterborne spar" product, but I guess it's possible to generate similar characteristics with an entirely different chemistry, although I guess it could be an oil modified (emulsified) product that still uses "long oils" so it stretches and bends. Which is the whole point of spar varnish. It's soft and flexible. For things that "don't move like spars", a marine varnish would likely be a good substitute. Consider contacting Total Boat about their marine products as they do have a bunch of waterborne products

[John TenEyck]

The outdoor rated exterior WB products fulfill the properties of traditional spar varnishes. Look at TC's literature for EM-9300 and GF's for 450 Exterior. Both talk about the UV absorbers they contain to protect the finish and TC specifically mentions the film is "hard yet flexible".

Both products are easily sprayed with conventional equipment. Both can be applied by brush or roller. And both will require routine maintenance, just like traditional spar varnishes.

John