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Building a sign box with VHB tape

biggmann

New Member
We have heard about from other sign shops they dont weld anymore and use Tesa tape to build sign boxes. We have considered this instead of welding them but want to see if anyone has done this first hand and their experience.
 

MikePro

New Member
interesting. maybe smaller boxes, for quick-flips?

in theory i'm sure it could work, but my only experience with it is with closing a box with a panel: Building the sign structure, and leaving a section out for access to weld/install, and placing the final panel with VHB tape as the last-touch when mechanical fasteners may look obnoxious. Sometimes even full 4x8 sheets of .090 aluminum, so I guess my main point is that it holds just fine over time. ...but I won't trust it to hold the entire weight of a large sign cabinet. ...or a large piece of metal over someone's head. Chaos theory dictates that tape will a way to delaminate, and ruin your day.
 

Moze

Active Member
It's done frequently. Whether or not you use strictly VHB tape or you use VHB tape along with stitch welding or other supporting attachment methods depends on the size of the sign, it's exposure to winds, engineering requirements, etc.
 

DigiPrinter

New Member
I'm not an engineer, I sometimes play one, but I personally wouldn't want to build or hang a cabinet sign built with VHB tape. My fear would be over time a worry of adhesion failure due to condensation/moisture, not to mention winds and other elements. If the VHB tape was backed up with some stitch welds or mechanical fasteners then OK, but why would you use VHB tape at all if you've got welds or mechanical fasteners or LORDS Adhesive? Sounds like a "hey, let's use .040 to build this cabinet instead of .090+ so we don't have to weld".
 

Moze

Active Member
Because, when used properly, it's a fast and proven method of building a sign.
 

Gino

Premium Subscriber
Does Lord's Glue or tape pass U/L codes or city building codes ??

I would think after a short while according to climate changes in certain parts of the country, sun exposure or any other number of conditions, the tape could very well fatigue. I'd hate to read the headlines..... "Sign Cabinet falls from side of building held together with tape." How many injured won't be known, due to the number of people it fell on. Heck, you could just tie it together with wash line and duct tape and call it a day.
 

Marlene

New Member
I'm not an engineer, I sometimes play one, but I personally wouldn't want to build or hang a cabinet sign built with VHB tape. My fear would be over time a worry of adhesion failure due to condensation/moisture, not to mention winds and other elements. If the VHB tape was backed up with some stitch welds or mechanical fasteners then OK, but why would you use VHB tape at all if you've got welds or mechanical fasteners or LORDS Adhesive? Sounds like a "hey, let's use .040 to build this cabinet instead of .090+ so we don't have to weld".​

+1
it may be a method used but I sure wouldn't want to do it. adhesive dries out over time and I've seen signs hung with it where the adhesive is brittle and powdery. not a big deal on a 6" x 6" ADA interior sign but for an exterior sign, no way
 

Mosh

New Member
I use VHB to hold stuff in place so I can rivet them, makes it feel stronger than rivets alone.
 

Moze

Active Member
It's not used on large signs all by itself. The OP didn't specify what size cabinet he's building, but on smaller cabinets, when customers specify "no visible fasteners", there are certain instances where a sign can be partially or wholly assembled with VHB tape. Again... It depends on the size, install location, etc.
 

Gino

Premium Subscriber
Well, not many small signs are welding together, so I figured the OP was referring to a somewhat sizable cabinet. Whether it be indoors or out in the weather, I can't see how an airport, grocery store, school, hospital or any other place.... where patrons, students, customers or whatever are milling around by the hundreds with signs overhead being held together with tape. I don't care how strong it is initially, it is going to fail long before a physical fastener, rivet or weld will give out. As mosh mentioned, we often times use the tape to hold something in place before physically putting real fasteners in. Heck, last week I used double-sided tape to put a bunch of overlays on some brick walls before screwing them fast. The tape held perfectly, but again, I'd never trust it over time.
 

MikePro

New Member
pics to follow, when I can un-bury these signs I just removed for replacement, but I just demo'd two 4'wide x 6'tall x 8"deep sign frames that were completely constructed using VHB tape and what appears to be a sad attempt at a Seal-It Foam filler.

my first thought: "Osnap! I just posted in a thread about this last week!"
signs had been up for nearly a decade, and finally took a semi-truck backing into them to destroy.
 

Chriswagner92

New Member
I apologize as i stopped reading after ginos comment, not that that has anything to do with gino just forgive me if this has already been said.

VHB is great stuff and I think it could last a couple years. Check out Modern Marvels 10 strongest episode, it made it to like number 7 i think. They did a comparison of two sheets of aluminum, one riveted, and one with vhb and they swung a bowling ball at the seam. The riveted panels failed almost instantly, while the vhb side got dented.

They also used the stuff on the sheeting of a hotel in Dubai i think, because it expanded and contracted with the intense sun it would last longer than welds. It's a cool segment you should look for
 

Marlene

New Member
flat surface to flat surface it one thing, corners are another. all the cases for how strong it is is on flat to flat. how about connections at the 90 degree bend?
 

Moze

Active Member
Some of the responses almost seem to indicate that manufacturing a sign cabinet with VHB, welding, bolts, etc. has to be an "either/or" scenario. The point, again, is that there are obviously limitations to what the tape will hold. Tape, stitch welds, rivets, screws and bolts all have failure points. Can every single cabinet in the world be manufactured with just VHB? No. With just bolts? No. The larger the cabinet, the higher the wind load, the more sheer force, the more salt in the air, etc., the more you have to adjust your attachment methods.

Sign cabinets are manufactured all of the time with just VHB tape. If you have a "small" cabinet sign, it's likely going to be constructed from 1" aluminum angle framing. The face (assuming it doesn't have to be removable for service) the returns and the back can all be attached with 1" wide VHB tape that is specifically engineered for aluminum-to-aluminum attachment and will meet or exceed engineering requirements. If you clean the aluminum properly and you apply the recommended pressure to the VHB when applying, the cabinet isn't going to come apart without some major event...but that same event would cause the same damage to a welded or bolted sign.

I've had to remove more than my share of aluminum faces that were attached aluminum framing with VHB tape. It requires pry bars and hammers. If you don't believe in the strength of VHB, you haven't tried to removed it.

Now increase the cabinet size and use 1½" or 2" aluminum angle covered with VHB tape. It's insanely strong.

3M has a very informative website. If you build signs, you should read up on the capabilities of their tape. I don't have it all memorized but as an example, one square inch of VHB tape will hold 20 pounds of sheer weight for a literally stupid amount of time. So lets say you have a 4' x 8' cabinet with 1" aluminum angle framing. You apply VHB tape to the perimeter of the face framing. That's about 24' of VHB tape. That's 288 of tape which will hold a sheer weight of 5.760 pounds. A 4' x 8' x .125" aluminum face weighs just under 60 pounds.

The stuff works. If it didn't it wouldn't be used by national sign companies and sign drawings wouldn't be approved by engineers.
 
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