Using PVC for an exterior dimensional sign

[gnubler]

Is it ever a good idea to use routed PVC/Sintra pieces for an exterior dimensional sign? All my research leans toward no, but then I came across this sign in my neighborhood that appears to be 1/2" black PVC, some faced with blue vinyl, adhered to a sheet of ACM (see pic). Adhered, not fastened, there's no screws on the back. PVC is known to get brittle in cold temps and contract/expand. I'm currently bidding on an exterior wall sign and looking into fastening 1 inch thick painted PVC letters to a substrate. My sign is north facing. Considering painted PVC because I don't want the glossy look of acrylic for this sign.

Appreciate any real world experience, good or bad.

 

[Jason Thomas]

I'm not sure if this is still available, but years ago I would use a 1/2" PVC that was exterior grade, supplied by Harbor Sales. You could probably get away with the interior grade if you are painting the faces and sides of the letters though. I've done signs exactly like the one in the pic, (vinyl face letters on ACM), though I've screwed the letters from the back AND used VHB tape. I've used interior and exterior grade PVC, no issues that I know of. I probably wouldn't go less than 1/2" thick though.

 

[gnubler]

I was thinking about using 1" thick PVC for my project. It's a big sign, two panels seamed.

Question on using VHB: Doesn't its thickness lift the letters from the substrate just a bit? I want mine to be tight and flush, without a gap where dirt/water can get beneath.

 

[Jason Thomas]

I'm sure certain thicknesses of VHB would lift the letters. Mine was pretty thin. The screws helped draw it tight too.

 

[GB2]

There are different grades of PVC, some for interior and some for exterior use. Black PVC is typically an interior product but different manufacturers may have an exterior Black PVC. What you are proposing is a very viable solution, PVC can be a very appropriate choice for exterior signage. Also, Sintra is merely a brand name of a particular PVC.

 

[Billct2]

I have used PVC for panels or letters on outside signs. Sometimes the exterior grade, sometimes not. Always painted both sides. Haven't noticed any issues. One was a set of address numbers a client needed in a hurry so I cut them painted and stud mounted. They were still looking good 10 years later when they moved. I won't use PVC as a background though, seen too many broken.

 

[gnubler]

By "painting both sides" do you mean the face and sides? Not the back attached to the substrate.

 

[Scotchbrite]

As others have mentioned, make sure to use exterior grade. The interior grade material will absorb moisture and the exterior is supposed to lock it out. A long time ago I made a layered 1/2" PVC sign. It was painted with Mathews. I don't remember how long it lasted, but it was quite a lot longer than I expected.

I remember being told at one point if you were cutting letters from PVC, not to make them any larger than 12" tall.

I should add I live in an arid climate so that might help.

 

[Gino]

Most of the time, if you're using 3/4" or greater, you're gonna have exterior grade. 1/2" is a 50/50 guess. And you won't know for sure, cause the distributor will tell ya anything to make the sale and get ridda sh!t.

 

[Billct2]

Yep, for pin mounted letters painted them front and back.

 

[gnubler]

Most of the time, if you're using 3/4" or greater, you're gonna have exterior grade. 1/2" is a 50/50 guess. And you won't know for sure, cause the distributor will tell ya anything to make the sale and get ridda sh!t.

My supplier carries Sintra brand. Looking at the datasheet the 12.7mm and up is called "Sintra Construct" and says it has high resistance to moisture, but doesn't specifically say it's rated for outdoor use.

 

[Gino]

In all of the pvc we use outdoors, I'd say 90% is 3/4" or better. 1/2" will just move on ya too much. Either be safe or go home.

 

[johnnysigns]

komacel is the outdoor grade PVC that vycom makes. Harbor sells it. It's got a smoother finish on the front and back and has less air blown into it so it's denser and less susceptible to warping. It's pretty common for outdoor signs in the Northeast.

 

[sardocs]

Most of our suppliers sell us sandwich boards made from pvc. One client wanted a black one and it got so soft it folded up on itself.

 

[signheremd]

komacel is the outdoor grade PVC that vycom makes. Harbor sells it. It's got a smoother finish on the front and back and has less air blown into it so it's denser and less susceptible to warping. It's pretty common for outdoor signs in the Northeast.

There is as Komadur

 

[kcollinsdesign]

I use EX-Cel exterior grade PVC and either glue it to an ACM panel or build an aluminum frame (you can use Alumawald and a propane torch if you don't have a welding rig). Lexel is a good adhesive to attach PVC elements; I will usually drill some small holes on the glueing surfaces to create a better mechanical bond. Matthews acrylic polyurethane would be a suitable finish; some spray paints (I've had good luck with Krylon Fusion) will work, but test first and properly prepare your surface.

Going commando with PVC is a bad idea. The material will warp (especially black).