Best finish for outdoor carved sign

[charliew]

What would be the best procedure for finishing a large, carved sign which will remain outside in Florida weather year-round? The details are painted with JoSonja acrylic paints and the woods are basswood and western red cedar.

[Big Barn]

If you don't mind shiney - I use a two-part marine epoxy on my fishing lures. Don't see why it wouldn't work on a sign ? I could be wrong !!!

[twymanok]

I use spar varnish or PolyUerethylene

[Steve Reed]

If you use a poly finish, make sure it has a UV protectant in it. Other wise it will yellow. You might think about something like tung oil, but you'll have to re-treat it every year or two.

[bob easton]

You might want to try the question down in the Relief carving forum. Ron Ramsey (aka telecarver) hangs out there. Part of what he does is outdoor signs, and I'm guessing that long experience has told him what works well.

[Tim Gagnon]

We use Helmsman spar urethane by Minwax on outdoor chainsaw carvings . It seems to hold up the best with several coats and is available in gloss ,semi-, and satin finish. Approximately $10 a quart or $45 a gallon at Lowes or Home Depot. I've had good luck with it on signs, too. It has UV protection which is very important. Good luck!

[carvingbarn]

I also use a spar varnish on those out door carvings. I like the oil base best. I thin the first coat 25% so it will penetrate deep in to the wood. Then two more coats. The oil base will darken the wood more than a water base.

[telecarver]

Any clear, shiny or satin impervious finish will yellow and peel fairly quickly in the weather. The UV is the culprit. The best impervious finish I have found is Sikkens. Even Sikkens needs regular maintenance and it is pretty messy and stinky to apply. It also a nightmare to refinish if you let it go too long before refinishing. The best you can expect is about 4 or 5 years and that's being optimistic. Spar urethane will only last 2 or 3 years in direct sun. Solid opaque exterior paint over the entire surface is the most durable. I have done tests of the major brands lasting 15 years in full sun and Fuller Obrien paint is the best.

For a natural wood finish I use a penetrating a oil sealer of a type you would apply to a deck. It is very quick and easy to re-apply so it is more likely to be done. Sun is the most damaging factor so I recommend periodic reapplication of the sealer. The schedule for periodic maintenance will vary with your sun and weather exposure. A sign that is under a covered porch that receives no sun will only need cleaning from time to time. If the sign is in full sun with exposure to rain and snow, it will need yearly maintenance. Spring, before the hot summer sun is high in the sky, is the ideal time for this. The way to tell if your sign needs attention is to observe if the natural wood portion of the sign looks dry and lighter in color. I recommend Preserva-Wood, Pacific Redwood color. Penofin Wood and Deck Stain is a good substitute. Superdeck, also called Duckback, is not recommended. It contains a hardener that does not allow the finish to penetrate sufficiently.

I have done hundreds of signs with this finish. The signs that have been maintained regularly still look good after 30 years. The signs that have been neglected start looking bad after 3 or 4 years.