Best way to join 2 pieces of HDU for long sign?

[FatCat]

Have a request to do a sign for a new customer. This will be anchored to an exterior wall on an outdoor mall. I have a 3 page document showing the requirements for the sign showing it must be made of HDU or wood, dimensions must be 28" x 168" to match other signs, and depth must be 1.5" thick. This sign is basically flat with a routed edge with only paint and vinyl graphics applied to the surface.

Don't have a lot of experience with HDU, so I am wondering what will be the best way to join 2 pieces together in the middle to form a 14' long sign out of 2 pieces of HDU? Would using dowels work? If so, what size dowels would be sufficient and what type of glue or adhesive? Any other options or methods that I am overlooking here?

Thanks for any help.

 

[sinetist]

I did one that was 12' long x 24". I routed a 3/4" deep slot in middle of the two ends to be joined and used a piece of MDO for a spline then used the foaming urethane "Gorlla Glue" for bonding the two pieces together. It's still fine after 8 years.

 

[eahicks]

Why do they have to be joined to install? Won't they be "joined" when they are mounted to the wall? I would think installing a piece that long would be a pain.

 

[J Hill Designs]

join em the same way you would join wood - spline joint (as above), butt joint works but is weak, dowel joint, biscuit joint, etc...

as for eahicks, the reason is less chance of the seam splitting

 

[Circleville Signs]

+1 to Gorilla Glue - but I wouldn't join it UNTIL the install.

If it is being wall mounted, I'd make a frame for it (ideally, aluminum) and mount that to the wall, then mount the sign to the frame. The mounting will hold it together so that the Gorilla Glue won't foam out and push it apart. You may need to go back the next day to scrape any glue that foams out.

 

[fixtureman]

Ship lap with Gorilla glue and install as one piece.

 

[FatCat]

Think I'm going to go the route of using dowels and finishing it prior to hanging. All the existing signs look like they are one piece (even though I know they're spliced together) and I need to make everything look consistent.

I appreciate all the advice, thanks!

 

[Techman]

HDU is a very expensive substrate for some paint and vinyl..

 

[mike ham]

1 inch ship lap gorilla glue wood screws to hold together untill dry. remove screws fill holes autobody fill, block sand seam ensuring smooth joint. skim coat entire sign with spot putty sand smooth this will ensure no shiners from seam and screw holes.

 

[Just Another Sign Guy]

lots of good advice. It sounds like hiding the seam is necessary (if it wasn't I would just butt them together during install) but since it appears no visible seam is the objective I would route slots in the back & install multiple lengths of stock aluminum square tubing spanning the gap of the sheets of hdu & then skim cote the face with autobody filler..but wow what a lot of work & expensive material selection for a flat non dimensional sign.

 

[SignManiac]

HDU is a very expensive substrate for some paint and vinyl..

Have to agree with Tech on this one. Very easy to give the appearance of 1.5" thick and using either PVC or aluminum face. All sorts of tricks for building out the edges and routering.

 

[Techman]

get some 1/2 " hdu and build up a base/ You will save several hundreds of cash.

 

[CES020]

For it's purpose, you could cheap out and go 10lb HDU and save some money as well.

 

[FatCat]

HDU is listed as a requirement in the build specs of the sign.
Not my choice - just gotta' do what they're asking.

 

[Stuckup]

TELL customer to jump, usually specs are just some loser workers only knowledge of 1 aspect of a job. GIVE AT LEAST 1 alternative. The desperate guy takes lowest quote, the standard guy takes 3 quotes, the money maker just uses the guy who who can do anything, whatever the cost. FFS, ask client can you re write specs, to suit their needs.

 

[weaselboogie]

Customer "requirements" are usually made by someone who doesn't have a clue what they're talking about.

I just had some specs thrown to me by the customer and while it was doable, it wasn't feasible. For their one quote request, I gave three.

A. What they wanted
B. What they needed instead
C. Same concept with an upsell to a better concept, layout.

B it is!

 

[Marlene]

Customer "requirements" are usually made by someone who doesn't have a clue what they're talking about.

true but if since it is a mall and you are matching the other signs, do it the way they asked.

lap, not butt is the best way to join

 

[Billct2]

I agree with the 1/2" HDU face on a 1"x1" aluminum tube Frame (the sides of the frame cann also be HDU.
It will save a lot of money and weigh half and still look like the other signs.