• I want to thank all the members that have upgraded your accounts. I truly appreciate your support of the site monetarily. Supporting the site keeps this site up and running as a lot of work daily goes on behind the scenes. Click to Support Signs101 ...

Filling / sealing voids in MDO

Billct2

Active Member
If you do a search on painting MDO you'll get lots of opinions. When we do use it we will usually use Phenoseal paintable chalk.
 

Z SIGNS

New Member
Putty paint and make it what it ain't

With all the choices of sign substrates MDO is a poor choice.
 

Techman

New Member
there is two MDO'
One for concrete forms etc and another for signs.

The concrete style will have voids.. Usually cheaper in price and you spend time filling voids. By the way. If one sees voids at the edges there are certainly voids inside. And those voids will cause a failure... One day one can see strange depressions on the face.. Tiny cracks will appear around those little depressions and suddenly there will be a blister and failure..

Sign grade will not or at least should not have voids..

Make sure to get sign grade MDO. It costs a little more but it is what it is.
 

Signmaker1234

New Member
Putty paint and make it what it ain't

With all the choices of sign substrates MDO is a poor choice.



Why is MDO a poor choice? I have a MDO sign going on close to ten years, still looks good. The 751 vinyl is still looking good also. The paint ( latex ) is not as bright, but still holding up. I actually love using it, I like the prep work and it's easy to cut. I get mine from N. Glantz pre primed. Hardly any voids, but when there is I use a paintable caulk, seems to work good. What do you use instead of MDO?
 

Gino

Premium Subscriber
Why is MDO a poor choice? I have a MDO sign going on close to ten years, still looks good. The 751 vinyl is still looking good also. The paint ( latex ) is not as bright, but still holding up. I actually love using it, I like the prep work and it's easy to cut. I get mine from N. Glantz pre primed. Hardly any voids, but when there is I use a paintable caulk, seems to work good. What do you use instead of MDO?

I'm with ya on that. I'd rather use MDO, or what we used to call it, durably, than any other substrate. Prepped properly, I've had it last well over 20 years. It only takes a short time to do it correctly, but the painting time is what holds us back from doing it much, anymore. People today have been conditioned and cant wait for the paint to dry, let alone ink to dry. Today's customers have no understanding of what goes into a well made sign. It's all about the bottom line cost and that usually means the newer substrates with the cheapest ink and vinyl which generally won't last more than 4 or 5 years.

So, given a choice, do you want to sell a sign for, let's say......... $450 and last 20 years or sell one with built in obsolescence of 5 years for $250. ??

Here's where reputations are created. Sure, aluminum products won't rot and neither will all the plastic crap, but aluminum oxidizes in about 2 years and all the PVCs are brittle in cold and warp in heat. Granted, these are projections based upon the common signs by common hacks. Some of these substrates will and can last longer, but not without taking extra care, just like with MDO.

We use Elmer's water based wood putty and fill the voids 2 or 3 times, buidling it up, so it lasts...... and then a bead down the 4 sides, sand off and prime, then top coats.
 

Bretbyron

New Member
Durham's "Rock Hard" Water Putty. It's like Bondo for wood and stainable. Mix it thick for vertical application and it will not stain through your paint.
 
Top