I’m stuck trying to decide how best to mount the sign and how to protect it. I’ve gone back and forth a bunch of times. Ugh.
The critical (and interrelated) issues:
- How to protect the “paper” panels to keep the vulnerable top edges from peeling
- How to mount without having the mounting fail or allow water damage
Protecting the top edges
The original plan was to apply some clear overcoat to protect the edges (especially the top edges) of the paper panels and to provide some UV protection so the printer inks wouldn’t fade so quickly. Ideal would be to put a sheet of polycarbonate or something over it, but that’s expensive and makes the sign more complex.
There is adhesive overspray on the plastic around the panels, and I’m afraid that will keep the spray overcoat from adhering well – particularly at the vulnerable very top edge of the panels, which is what really needs mechanical protection.
It feels like there should be something lapped over the top edges of the panels. That would both keep water from trying to get under that top edge and provide at least a little mechanical support holding the top edges in. One possible way to do that would be to have the panels come to the very top of the plastic, and slip an upside-down U shaped channel (maybe 0.5″ high?) over the top edge. Much like the slip-on spines of clear plastic report covers, if anybody knows what those were. Of course it would have to be the full width of the sign for no leaks, and I don’t have any candidate materials to make it from. (Are there cheap plastic poster holders that would work? The corrugated plastic is 4mm thick, so something that would just hold a sheet of paper wouldn’t be a good fit.)
The problem with that is that then the mounting holes would have to penetrate the panels themselves. It just seems like water would manage to get in no matter how you treated the holes.
Yet another approach is to cover the whole sign with a piece of thick vinyl shower curtain (which I have). If that were folded over the top, it would protect very well from water, as well as kind of holding down any edges that started to peel. But then how do you hang it without piercing the vinyl? A metal backing plate would work… But how do you seal the edges and bottom? And would the vinyl yellow too badly in the sun, or just not stand up to the temperature extremes?
Hmm – what about a strip of the same waterproof paper maybe 3″ wide and as long as the width of the sign (OK, it would have to be pieced from the 11″ sheets I have). It would be folded over the top of the sign, lapping over the top edges of the printed panels (on both sides). That strip would be glued down just like the panels. Worst case, even if its bottom edge came loose, it would still provide significant water protection to the top edges of the panels because it lapped over them. Mounting holes would penetrate that strip, and might leak, but that small leakage (if any) would be the same as rain sheeting down over the top edges of the panels, but many orders of magnitude less.
I left space above the panels for mounting holes that wouldn’t penetrate the panels, avoiding a possible source of water leaks. I planned to slide a heavy wire/thin rod through the second-to-top flute of the corrugated plastic and drill holes for mounting right below that. That all happens above the top edge of the panels. The rod would dramatically spread out the load the hangers would place on the holes in the plastic. I suspect that would be sufficient for mounting the quite light sign.
Another mounting idea is to back the whole sign with an aluminum plate. I found an old 24″x26″ RS-232 patch panel made of 1/8″ aluminum that would work. There’s obviously some disassembly, cutting, etc, but that’s not a show stopper. The plate would extend above the sign by an inch or so, allowing mounting holes that don’t compromise the sign in any way.
I think something like “Liquid Nails” exterior construction adhesive would work to stick the aluminum to the back of the sign. The original plan had been to have lettering on the back of the sign as well as the front. The aluminum back interferes with that, though a second piece of plastic with the back side lettering could be glued to the metal plate as well. But we’re adding more and more complexity.
Part of the intent of the sign was an experiment in minimalist sign-making. The back plate would make a much more robust sign – which is a good thing – but diverges from the intent. If I chicken out and put lots of protection on the sign, we get a sign with longer life for the space – which is great. But I lose the information about how the minimalist design works. Would it hold up for a day? A week? A year?
So my head races in circles from original minimalist to heavy duty aluminum plate with two vinyl covered printed surfaces to the simple, effective protection of a U channel over the top – but then what about water leaks at the mounting holes? I’m sure you know the phemomenon.
Suggestions are welcome!