[r3bb]

I'm looking to make a fairly large sign/logo to go on an outdoor wall, but I'm not sure what to make it from.

I'm fairly handy with mdf - easy to cut and shape - so would sealing and painting it make it suitable for outdoors and exposed to the elements?
Plywood seems like it would be tough to smooth off.

Acrylic was another thought, but I don't know where to buy a large piece of it - approx 500mm x 1000mm.

 

[bird dog]

I would use MDO.
Called MDO, or medium density overlay, it's engineered plywood with a resin treated fiber applied to both faces. This gives an extremely smooth finish that is easy to paint. In addition it's rated for exterior use, which means it is safe from the elements, insects, or other outdoor hazards, making it a perfect choice for the new deck or porch.

 

[trim man]

I'm looking to make a fairly large sign/logo to go on an outdoor wall, but I'm not sure what to make it from.

I'm fairly handy with mdf - easy to cut and shape - so would sealing and painting it make it suitable for outdoors and exposed to the elements?
Plywood seems like it would be tough to smooth off.

Acrylic was another thought, but I don't know where to buy a large piece of it - approx 500mm x 1000mm.

Don't use regular mdf. It is not an outdoor material. They now make a mdf product that claims to be for outdoor use, but it doesn't have a track record, and I would not trust it until is has proven itself. Anyone remember the fantastic marketing claims of Masonite brand siding in the 70's? Literally tens of millions of feet were installed on houses before it all starting disintegrating from moisture a couple of years later.

Like suggested, locate some mdo. It is tough stuff and very smooth finish. Next choice would be a piece of MARINE grade plywood coated with three coats of epoxy resin.

 

[Rob]

MDO would also be my choice. Most of the huge green turnpike signs are made from it. It is weatherproof as long as it doesn't come in contact with the ground.
Comes in 1/4", 1/2", 3/4" and 1". The stuff I buy is pre-primed. Last purchase was in January...$75 per sheet for 3/4"

 

[danesm]

I would not use MDF. If you do use MDF make sure to use Exterior and I would coat it with a 2 part epoxy but it still will not last over the long haul. They have sheets of of pvc called Azek it is light weight and mills like wood you can also glue it together with their glue. It is not cheep but well worth it.