how to finish an outdoor painted wooden sign

[3cpq]

I'm making a sign for my uncle as a Christmas present.  The it's basically a fame and panel, the frame is walnut, and the panel is black oak.  The panel will be mostly or completely painted, and the frame will be not. 

What's the best way to go about sealing and protecting it?  One thing I don't want to happen is for the finish to turn white, or cloudy, crack, or turn yellow and flake off.  For this reason I was thinking a penetrating oil finish, but I don't think that would do much for the painted surface.  Now I'm thinking epoxy, or a marine varnish.

Thanks, Merry Christmas and Happy Holidays 

 

[peter halle]

I was looking for pictures of a sign rebuild a few years ago.  I used a thin epoxy to coat the entire sign, then painted.  The paint is in perfect shape 6 years later.  If you look into this approach, look for a consolidant type epoxy - designed to soak in - and follow directions.  For the frame, after consolidating, apply an exterior spar varnish - preferably with UV inhibiters.  Helps with the yellowing and the blushing issues that many epoxies have.  If I find photos of the project I'll post them.

Peter

 

[3cpq]

I am considering using Penofin's exterior hardwood penetrating oil finish, for the frame.  Would this stuff hurt the paint if I went over the panel with it as well?  Would it help protect the paint?

 

[PaulMarcel]

+1 to Peter's point.  The local paint store has a penetrating epoxy sealer you put over paint (even old paint that is currently flaking off) and it holds it for good; on fresh paint, it would keep it pristine.  Just need to deal with UV like he suggested.  If you have Epifanes varnish, it is very good for UV protection.

 

[3cpq]

Thanks for the advice, I'm going to use an epoxy sealer, and a good marine varnish over that.

Here's a pic of the sign.  It's his family crest from Switzerland. 

 

[peter halle]

Now that I've seen the sign, I would change my opinion of what to use.  The penetrating epoxy I mentioned would have been good on bare wood before and painting.  It will not soak in thru the paint.  Depending on the paint type - latex or oil - there may be a compatibility issue also.

I know that you said it is a Christmas present, I would hate to see you ruin an absolutely beautiful sign putting on a finish that turned your art piece into a mess.  Maybe Paul can get you a name of the product he was thinking of and you could so a trial sample.

Peter

 

[PaulMarcel]

I'll get the name of the product tomorrow as the paint store is closed.  I know I took a brochure since it would be exceptional for many things.  It is specifically designed to go -over- existing paint.  Prevents paint check, peeling, etc.  Something like Smith's CPES is, as Peter mentioned, a raw wood epoxy-based sealer.

So, it'll cut it close but I'll see if I can find the brochure so you can get started... but -definitely- try it on a scrap with paint on it to ensure the results are what you want (sheen, application method, etc)

Looks great!

 

[PaulMarcel]

No sooner did I hit 'post' that I remembered its name

It's Zinsser's Peel Stop.  You can even apply it over old flaking paint to re-bond and seal it.  Note that it's breathable, which is better for an exterior application anyway.  The first several bullet points are more for existing damaged paint, but if you read to the bottom of the list, you'll see that naturally it can help prevent a lot of those problems it intends to fix.

Report back, please.  I have not used it yet, but wished I put an overcoat on my house soffits... Arizona sun is mean.

 

[3cpq]

I put a few coats of Peel Stop on last night, so far looks good.