Anodized Aluminum vs Outdoor Weatherable Plastic

[Liesl Dexheimer]

When creating outdoor weatherable signs/bench plaques I usually favor plastic over metal. What about anodized aluminum? Will it hold up close to the same amount of time as outdoor weatherable plastic? What other options would you suggest? I know I could go with cast plaques but I'm looking for a budget friendly option.

[Bert Kemp]

I had some anodized dog tags I put outside to test. It didn't take long for the colored tags to start to fade. Now maybe you can paint the alum with a uv resistant clear coat. I haven't tried that. But that add expense and time to the job.


When creating outdoor weatherable signs/bench plaques I usually favor plastic over metal. What about anodized aluminum? Will it hold up close to the same amount of time as outdoor weatherable plastic? What other options would you suggest? I know I could go with cast plaques but I'm looking for a budget friendly option.

[Kev Williams]

Depends on who's anodizing and their methods. Outside facing the east sun I have these 3 aluminum panels anodized by 2 different local shops. They've been out there about 5 years now.

I haven't moved these in about a year.
360130

Note the other side of the smaller one is still nice & black,
the sun is obviously the problem with the big panel,
but the medium panel is the same on both sides.
It's faded a tiny bit, seems mostly due to age since the
back has barely if ever seen direct sun and it's a near match
for the front...
360131

There is UV proof anodizing called "architectural" anodizing, not sure of the 'type', and the shop that supplies the faded version has never heard of it. Hmmm... I'll bet the other shop has! And what's in these pics is just their 'standard' anodizing, as they take pride in their work. Mostly, as I understand it, fading has to do with the type(s) of dye the shop uses. Some shops will cheap out obviously...

There's nothing you can spray on that will help, other than paint! ;) -- clear will just make it fade faster most likely...

How 'over the counter' anodized aluminum fares outdoors, I have no clue, as I've always had my material made up from scratch...

CLEAR anodized that is engraved and painted, should pretty much be okay for outdoors...

[John Lifer]

JDS had some black sheets for exterior. Made two for my gateill tell you in a couple of years. Didn't engrave really well. Probably too much power.

[Mike Null]

Missouri Botanical Garden, which was a customer before they bought a laser, switched from anodized to engraver's plastic because they get longer life and better UV stability. They have several thousand outdoor signs.

[Liesl Dexheimer]

As far as I am concerned plastic is the way to go for outdoor weatherable signs. Unless of course the budget allows for cast bronze or aluminum.

I have a customer now that wants to switch from Metalgraph plus plastic to metal for bench and picnic table plates. Going to have to convince him that plastic really is the better choice.

[Keith Outten]

I have had to replace aluminum exterior signs for customers in the past, not only do they fade but in our area aluminum always corrodes. We are on the East Coast so salt is in the air here constantly. At CNU I tried my best to replace every aluminum sign and all the building letters as fast as I could but I retired well before I finished the job.

Solid Surface material was my choice especially when the signs or letters were on an exterior surface. Every sign I made from solid surface material looks as good today as the day it was installed, over ten years and counting. The paint is still looking good as well and it is very easy to refresh the paint when it finally starts to fade. The Frat House signs that I made were white Corian letters on a dark blue Corian plaque and they were polished. They still look fantastic.

The cost of the material was offset by a reduction in labor costs and maintenance over the years will prove to be a fraction of the cost of using more traditional materials.

[Mike Null]

Keith
I second your recommendation of Corian but for me, it's almost impossible to get.