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MDO Life Expectancy

sinclairgraphics1

Sinclair Graphics & Installations
We have been using 1/2" MDO for years on site signs and it works well for those applications. For long term use, I know they recommend using trim cap, which for a square or rectangle sign is fine but a custom cut one not so much. The manufacturer offers a warranty for up to 66 months on the product. We have some permanent exterior signs we are going to use them for that will be custom cut so we will fill fill any small pin holes on the edges and primer them. What other substrate would you recommend that's 1/2" for an exterior sign like this? I know we could use 6mm max metal but that's a little too thin for these signs. I would think with properly sealing the edges the sign would hold up 10 years but it is still wood so if anything falls on it or chips the edges, moistures will pour right in.
 

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Gino

Premium Subscriber
If you fill all the voids and edges completely, like in 100% coverage in two or three applications, prime it, then paint it with 2 or 3 coats, you can easily get 15 to 20 years out of it. We've done it many many times. Have some signs out 25 years. The only thing bad on it, is the lettering started to fade. If ya do it today and put vinyl on it, it should still last a long time. The vinyl will fail long before the duraply.
 

sinclairgraphics1

Sinclair Graphics & Installations
If you fill all the voids and edges completely, like in 100% coverage in two or three applications, prime it, then paint it with 2 or 3 coats, you can easily get 15 to 20 years out of it. We've done it many many times. Have some signs out 25 years. The only thing bad on it, is the lettering started to fade. If ya do it today and put vinyl on it, it should still last a long time. The vinyl will fail long before the duraply.
Yes, we have some that have been around for about 10 years and still holding up. What kind of primer and paint do you like to use? We have used a Kilz exterior brand that works pretty well.
 

Gino

Premium Subscriber
Kilz is fine. We top coat with 1shot or chromatic bulletin.

Like I said, 100% of the edges, not just the holes or voids and do it in 2 or 3 steps, as filler does not cure well when packed in gobs. Build it up and after those 3 coats have thoroughly dried, sand the whole edge down. Now ya have edges completely sealed.
 

Cross Signs

We Make Them Hot and Fresh Everyday
I use a good coating of Gorilla wood glue on the edge of MDO. It soaks in and dries smooth. Then paint.
 

Gino

Premium Subscriber
Remember, if you look at his/her profile, he/she's up here in the north and goes through seasonal changes. Gorilla glue dries hard and will not breath with the various temperature changes up here and will eventually crack and peel...... badly. Also, most glues are not meant to be used as a filler/putty. Neither is caulk.
 

Billct2

Active Member
We used to make tons of shaped MDO signs. Used exterior patch to fill holes, one thin coat of oil based primer on the edge, then prime the whole thing. Two coats good oil base paint.
We found the quality of mdo has gone down but still use it occasionally. We have also bonded two layers of 6mm acm together.
 

Asuma01

New Member
We used to make tons of shaped MDO signs. Used exterior patch to fill holes, one thin coat of oil based primer on the edge, then prime the whole thing. Two coats good oil base paint.
We found the quality of mdo has gone down but still use it occasionally. We have also bonded two layers of 6mm acm together.
What do you use in place of MDO?
 

Billct2

Active Member
Like I mentioned, sometimes we bond two sheets of 6mm, great if you need a white or black background. Or we paint with two part auto paint, or sheet with vinyl.
For smaller signs I'll use 1/2", 3/4" or even 1" PVC. But pvc has it's own issues. Have to evaluate the job and pick whatever works best for a given situation.
For some single face signs 3mm acm is fine with a back support like an aluminum angle.
 

Z SIGNS

New Member
You can get MDO to last by using the above mentioned comments. But why use it? It's 2021 not 1965. To many better alternative products out there.
By the time you add up the time to putty and paint you can afford to buy a PVC sheet.
 

visual800

Active Member
MDO is crap. I stopped using it several years ago. We use .5" coro....lightweight, easy to handle no prep, no filling holes. letter it and get it up. If a client asks for MDO we invite them to use .5" coro or move on. Stuff is heavy also. Why spend all that time prepping and sanding
 

sinclairgraphics1

Sinclair Graphics & Installations
You can get MDO to last by using the above mentioned comments. But why use it? It's 2021 not 1965. To many better alternative products out there.
By the time you add up the time to putty and paint you can afford to buy a PVC sheet.
PVC for a long term outdoor sign here where I live wouldn't hold up with the extreme temp changes we have here. It gets to -20 consistently in the winter and the summers are humid af.
 

netsol

Active Member
Remember, if you look at his/her profile, he/she's up here in the north and goes through seasonal changes. Gorilla glue dries hard and will not breath with the various temperature changes up here and will eventually crack and peel...... badly. Also, most glues are not meant to be used as a filler/putty. Neither is caulk.
correct!
 

Johnny Best

Active Member
MDO use to have 5 or 6 layers of veneer, now it looks like 16 to 20 layers and with cheap Canadian wood. With all the prepping it is not worth it, ACM is my go to or Coro with metal veneer.
 
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