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Hot Topics: Waterproof a plywood sign

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Original post: How is it best to weatherproof vintage outdoor plywood sign?

Spock – Member

How best to weatherproof vintage outdoor plywood sign?

I picked up a really cool outdoor vintage hand painted plywood sign (2 & # 39; X 4 & # 39;) to use as a backrest on an outdoor bench I do. I do not know if the graphics on the sign were painted in oil or acrylic paint.

What is the best way for me to seal, cover or otherwise weather this plywood sign to maximize the outdoor life. I live in NC with four seasons but rare snow.


marksr ̵

1; Forum Topic Moderator

The most important part would be to seal the edges so that water / moisture does not get in between the sheets! [19659004] An oil base pair poly will discolor the sign [give it an amber tone] I do not have much experience with the water base versions but they should not discolor the sign. Whatever you apply for must be sharpened and repainted regularly to prevent it from deteriorating.

pugsl – Forum Topic Moderator

Connection Date: Mar 2008

I would oil the poly edges and use water poly on the rest of the characters. Oil seems to stick better in the weather. Edges may need to be changed every year.

man – Member

Depending on the thickness and shape you may want to put an edge outside.

Spock – Thread Starter

man, Tell me more. The plywood sign is 1/2 inch thick and rectangular at 2 ft by 4 ft.

man – Member

They make edging (basically a U-channel) in metal and plastic

Spock – Thread Starter

Would I find such a thing in a big box store like HD, and how is it attached to the edge – glue, nails, screws or something else?

man – Member

Yes, it should be available on the big boxes.

Pretty good which way you want to attach it.

The plastic material often has the U ends than the middle so it fits quite tightly.

I would put a small bead with clear lime on the bottom and sides to keep as much moisture as possible.

Marq1 – Member

The bottom line, if you want to keep it intact, get it out of the elements.

There is nothing, no coating etx that will protect it outside!

Spock – Thread Starter


You know, in the end you are exactly right. However, I can't help but wonder how this old character, who is probably at least 40-50 years old and has lived outside Pennsylvania, managed to keep himself in such good shape. Was it just the fact that it was painted or did the original painters do something else to preserve it? And if not, maybe I don't have to jump through the bows to touch it too – possibly a spray of Thompson's water seal and we go and get excited if it lives another 10 or 20 years.

marksr – Forum Topic Moderator

How were the edges exposed to the elements? The odds are that the sign was painted with lead-based paint, that and better quality plywood would play a role in how well it held. TWS generally lasts 6-12 months.

If I use the channel as Man described I would leave it from the bottom. Another alternative would be to install a bread plate [small narrow strip of wood] on the top and sides.

man – Member

I agree that marksr leaving it from the bottom is a good idea.

Should have thought of it himself. .

No matter what surface you put on it, there are some risks, so if possible try it on a small area before doing the whole sign.

 vintage sign on the bench

sign, added trim on top and sides, redesigned cool old sign in a bench backrest. Thanks everyone for the suggestions.

marksr Forum Topic Moderator

Looks sharp

What type of "paint" did you use? hopefully a pigment or save urethane. You should carefully inspect the surface every year because you want to sand and coat before the surface deteriorates too much.

Spock Thread Starter


I went with this:

RTG Outdoor Wood Furniture Paint from Atlantic Boat Supply Company – a water based polyurethane that was super easy to apply and dried clear and hard. I took on 4 layers (extra on the edges) before installing the vinyl stripping. I will keep an eye on it as we go, but I think it will work well.

marksr Forum Topic Moderator

I don't know about the special paint. In general, if external varnish is allowed to deteriorate too far, it must be pretty much ground completely by [which could affect the graphics] but if you catch it early, all that is needed is a light sanding and a fresh coat. Normally, the paint will look good for a year or more, even if it depends on the climate it is exposed to.

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