View Full Version : exterior sign

Craig Hogarth
09-02-2007, 2:06 AM
I just got my sign permit yesterday and will finally get to hang a sign. I haven't worked on it since I wasn't sure what size would get approved. So I'm approved now for a sign not to exceed 30 by 100 and must use the existing 6 holes, 2 rows of three spaced 48 inches apart with the top row 22 inches above the bottom.

I've decided to go with a 28 by 100 sign in 1/4 inch MDF coated with white melamine. Logo will be in vinyl. I chose this primarily, since it was readily available and light enough for me to hang by myself.

I'll be upgrading the sign eventually, but would like to know what I could do to keep it in good condition over what's sure to be a wet winter here in NW Washington State.

I'm going to put a 2 inch border around the sign with the vinyl wrapping over the edge. I'm not sure if I should paint the back or wrap it in vinyl. Or is MDF ok in this weather?

Scott Shepherd
09-02-2007, 10:26 AM
A lot of people seem to use and recommend PVC for that type of application. I haven't used it myself, but I see it recommended all the time. It's white, should take the vinyl well, and should hold up to the rain. I'm sure Joe knows and can offer up a more educated opinion than mine, but that's what I have heard a lot.

Joe Pelonio
09-02-2007, 2:17 PM
Where exactly are you? In Sequim I would go ahead with it, but anywhere else with 40+ inches of rain, that material has to be completely sealed. The melamine seam where the face meets the edges will be a weak point as well as the back. If you paint the back, then cover the face with vinyl wrapped around the edges and slightly onto the back, you should be waterproof. otherwise MDF will swell from moisture. I'd use MDO. You can buy it primed both sides and back from Northwest Sign Supply in Seattle and other sign supply places, or unprimed at better lumber yards (not the borgs). It's very outdoor friendly as is, when painted only the edges are weak and then if you fill any voids, prime and paint them even the edges should hold up 10 years.

MDO is an engineered exterior plywood with a resin impregnated paper surface. I pay $45 for 4x8 sheets, though you'd need 10' which will cost more and will be harder to find.

Craig Hogarth
09-03-2007, 1:05 AM
I'm up on Whidbey Island, so not a lot rain compared to other areas in WA.

joe, you got any tips on hanging it? I'll be doing it by myself and the sign is about shoulder height when I'm top of my ladder.

Scott Shepherd
09-03-2007, 8:56 AM
Joe, just curious why you'd use MDO instead of something like PVC or some aluminum clad PVC. Just asking so I understand how you select those things, so it'll help me select the right materials in the future.

Thanks for your help-

Mike Hood
09-03-2007, 10:38 AM

I'd also go with something synthetic or metal. If it's gonna be outdoors around here, the moisture will swell it in pretty short order. Unless you plan to seal the bejesus out of it the water will kill it in a year or two.

I've had good luck with 10mm coroplast holding up in the weather here. It also takes vinyl well (I'm in Lake Stevens if you ever need any vinyl help).

Where are you on Whidbey? I retired from there a few years ago (Navy)

Joe Pelonio
09-03-2007, 5:37 PM

Almost all of the big signs I do for outdoors now are made from a laminate of aluminum on PVC core, it's the longest lasting, but $110/sheet and only 1/4" thick. MDO is much better than MDF when 1/2" thickness is needed and you don't have an unlimited budget. I've also done .06/.08 aluminum with 1x2 on the edges like a frame, mitered corners.

Craig, for hanging MDO I like to use screws, countersunk, then place a small circle of the same color vinyl over the screw. Sometimes it looks nice if you have a couple of strips of 1x2 behind it to raise it out from the wall. By yourself, have a screw in it near the center, and your cordless on a belt. Walk it up the ladder and get that 1st one part way in. Then level and do the rest.

I'd still consider Whidbey too wet for MDF, but yes, you get a lot less rain than we do.


I too have had good luck with 10mm coro but it doesn't look as good with the ribs and the edges look bad unless covered with a molding. Another thing that's good is 13mm PVC, but it's hard to get a decent coat of paint on the edges.