XL HDU Sign - Can we salvage it?

[MBCSigns]

We had a 4'h x 10'w x 2" double sided HDU sign (with an arch along the top) fabricated last month, but did not know to request that the panel be reinforced with a rigid substrate between 2 single sided HDU pieces so it wont be in danger of cracking in half.

The plan was for the panel to be mounted b/t (2) Aluminum Posts using larger "L" brackets along the sides with a 2nd HDU panel in a 12"h x 72"w x 2" size hang mounted from the larger panel with chains and eye hooks.

Upon installation of the larger sign, our crew voiced concern over the possibility of it cracking in half after the first hard wind or rainstorm. That was last Friday, and sure enough, this morning, our crew called to report that when they passed the sign this morning, it was already beggining to bow out.

If possible, try to move past the obvious question (that being "Why would anyone produce a panel that big and not reinforce it?") and just fast forward to where I'm at.

What are my options? We dont produce HDU in house. So, any repair or replacement will cost us more $ and time. I may be reaching here, but:

Is it possible to slice an already sandblasted 2" thick panel right down the center to then mount a rigid panel in between?

Can a large panel be reinforced with channels along the bottom?

Can the panel be drilled into and be reinforced with any type of hardening substance?

 

[signguy 55]

I don't see how you can salvage anything. That is why I don't do HDU, everything I do is redwood or cedar. On the other hand, you may be able to get a piece of flat 2" steel strapping and attach to the bottom and sides of the sign to firm it up. That would firm up the edges, but the middle part of the sign would still have a tremendous amount of stress.

On installs I do, I use 1" angle iron either steel or aluminum, I can get this at Lowe's, I run it down the entire side and put about 5 screws in the sign and 5 screws in the post. All my signs have borders, I just paint it the border color and it blends right in. This is super strong, this may work on your sign, trouble is HDU has no grain like wood does, but should help.

Good luck.

 

[SignManiac]

There's nothing wrong with using HDU in your situation as long as you realize that a sign like your description needs structural reinforcing.

The only option you have considering the sign is done already, Is run a horizontal stiffener along the bottom assuming it's straight across. But...as stated already, I don't think that alone will be enough to keep it from snapping in the middle if a good wind or good kick should meet with it.


Edited to add. I always advise my clients about the structural limitations of HDU. If you work with it or sell it, you need to know this stuff.

Can you post a photo of the sign. There may be some other options to consider but as stated below, we can only guess as to what your sign looks like.

 

[Just Another Sign Guy]

i think your only options are to reinforce it as stated and HOPE it doesnt snap...but in time my money is that it will.

the next options i would really need to sharpen my pencil and see if it was worth the labor or not and would suggest you do the same. so what i would propose depending on the design would be to have a new single sided sign made on a thinner sheet build your internal structure (or sheet) in the middle and adhere the new panel and the old to the new structure...or if the design is such that so much of the sign is reliefed that it would present new structural issues if what i just mentioned was to happen plane down that side of the sign (either by hand or on a cnc if you have access)...and then again have a single face made as above.

if the sign was thicker i would possibly consider having cores drilled the 4' width of the sign and then covering threaded rods with epoxy and inserting them in through the holes and adhering them to a steel structure on the top and bottom .... but at 2" i don't feel good about that at all...my money would be that it would get busted during the 'procedure'...but i have seen it done on a 3"

 

[John L]

That's a pickle. Without seeing your layout.. I can only guess.

But do you per chance have two horizontal areas (One high, one low) about 2" high X the sign width that are not blasted? ... long shot, but maybe you could rabbet some metal into it and bondo it back over. Won't really work in a blasted area very well though.

Save for that, also pending the layout, and also not ideal as you know. You could possibly weld up a flat bar 2" wide with 1/2" steel dowels. Drill some corresponding holes in the signs edges and glue that into the holes. This could possibly also work on the shaped edge, within reason. We have a cnc machine here so I would make myself a very acurate template for trying such and locating the holes, the dowels, etc.

This is all kinda guessing at what you have of course. But if it isn't split yet, I would definately figure something out to save it.

 

[John L]

Another possible if you have a decent border around the blasted area....

Weld a flat with 2 "fingers" sticking up, all full length of sign. Sandwich the HDU in between, epoxy, throughbolt, etc.

The shaped area would require some sheet to make up a channel and that might cost the same as some more 1" HDU to make another side.

Gotta be a way to save that. I'm sick for you over here.

best of luck.

 

[Billct2]

I made the same mistake on our first HDU sign many yrears back.
It was a 4x8. I added a 2"x2" steel angle along the bottom and up the sides and it stiffened it up enough that it has lasted over 10 years. The side steel was to add more attachment points than stiffeness.
That was for a single face sign, for a double you could run a rout to hide the blade of the steel, or just paint to match.

 

[encadtech]

You could cut the panel in half on a horizontal bandsaw - Thus giving you the 2 faces seperated - then sandwich and glue MDO or PVC as a center core.

 

[Mainframe]

I would get 12 feet if 1/4" or 3/8 steel rod, make 6-3 foot pieces & weld them to flat "shoulder" pieces, drill into the sides of the HDU, -3 feet, "match up the rods!" you can use liquid nails where the rods go, now you have some steel rods inside & go ahead & install it, if you can, make the shoulder pieces longer so you can use them for the install.

 

[k.a.s.]

As others have said, I would put somthing along the bottom, this should prevent it from bowing and would prevent most weather conditions from affecting it.

I have mounted and 4x8, double sided HDU sign in between two posts and although it seemed flimsy it has withstood 5+ years of Ohio weather. That said, I no longer make double sided HDU signs for the most part, instead I always make two single signs and mount them on each sided of a treated frame. Works great.

Kevin