Outdoor clear varnish matt finish

[muvvers]

I need to protect and weatherproof a painted wooden surface. What would be a good varnish with a matt finish I could use?

[Clanad]

Any good polyurethane will do you. Sand the surface lightly to remove dirt and loose finish, give it two or three light coats rather than one thick one. To achieve a really nice, smooth finish, sand or steel wool the surface after it dries before adding the succeeding coats. Most can be bought in different glosses, from matt to high-gloss...

[muvvers]

Thank you

[jomifl]

High gloss is the most weather resistant, you should give it an additional coat every year.

[jomifl]

Yacht varnish has the best protection from UV which is polyurethane's worst enemy.

[muvvers]

Thank you. I particularly want a matt finish as I don't want it shiny. What can you recommend.

[muvvers]

Can I put polyurethane varnish on top of acryclic paint?

[jomifl]

I would imagine that acrylic paint has better weather resistance than poly. varnish. Modern masonry paint is acrylic based, it sticks much better than poly. and lasts better. If you want a durable (very)matt finish use masonry paint. ( but not where people (especially children) might brush against it as it can be a bit like sandpaper).

[muvvers]

Thank you, but I've just finished painting the wood with acrylic paint and want to protect it with a clear matt varnish.

[jomifl]

If it is exterior grade acrylic paint it will probay last better than the varnish. When the varnish weathers and begins to flake off it will most likely look worse than if you hadn't varnished it.

[Clanad]

I standby the recommendation of poly for your top coat. However, water based polyurethane would be better for your application rather than oil based. Additionally, buy a new, plain sponge (the kind used in kitchens) for applying the poly... cut it in 2 to 3 inch squares and apply sparingly in at least 2 coats... 3 or 4 is even better. It gives more depth to the finished product. Using the sponge eases the chance of small bubbles often formed with brush application that tend to whiten into an unattractive film.
The water based poly can be purchased in any gloss you'd like... especially matte or semi-gloss.
Good luck!