Mounting Sign Foam

[olddawg]

I'm wanting to do a 30" double sided 9' long sign. I used to do these in Redwood, but thought I would try sandblasting some sign foam, which I've never used. It's going to be double sided. The question I have is this sign is going to be suspended between a couple of posts and will have some ornamentation around the edges, so I can't put it in a frame for support. So, it will need to be supported from within. Can I sandwich a piece of plywood in the middle using glue? I'm thinking the wood would warp with time and would damage the foam. What might work better? And, what kind of glue? I'm assuming 3M spray glue, but maybe there's a better way to go.

Thanks for any help.

 

[tbullo]

I have many blasted signfoam signs that I sandwiched together with MDO and west epoxy. I would not use spray glue. I epoxy the pieces together then cut edges as 1 piece once dry. Then I seal it all up by coating out the edges with the west epoxy and a little fairing powder. I have signs done in this manner that have been up over 15 years. I'm sure there are other ways as well but this seems to work for me.

 

[rossmosh]

HDU/Sign Foam is decorative only. It's non structural. Most believe the best way to hang HDU signs is an internal steel/aluminum structure. If you do a little searching, you'll see all sorts of different examples.

As for gluing the two panels of HDU, Gorilla Glue works well otherwise Precision Board sells an HDU glue.

 

[visual800]

i would highly recommmend powting pics, that would really help us see what your working with

 

[olddawg]

Thank you

Thank you for the advise and suggestions. I'll do some more research. If MDO has held up for 15 plus years as a support for sign foam, sounds like that would be a good way to go. It would certainly be the easiest to work with. Probably 3/4" for extra stability.

 

[rossmosh]

Thank you for the advise and suggestions. I'll do some more research. If MDO has held up for 15 plus years as a support for sign foam, sounds like that would be a good way to go. It would certainly be the easiest to work with. Probably 3/4" for extra stability.

http://precisionboard.com/1uncategorized/our-cnc-machine-finally-arrived/
http://www.talkshopbot.com/forum/showthread.php?21899-2k-urethane-paint-on-signfoam-4

Those are two of the most common methods of mounting HDU

 

[Z SIGNS]

I have done many foam signs with mdo in between.
Some have lasted many years but I have also seen many fail.
I think the failure comes if any moisture gets to the plywood.It has no where to go so the mdo rots out.
Now we just do internal aluminum framing