Monster Stretch Face SignTurning Your Avant-Garde Sign Concepts Into Realities...
This job was quoted many months before Christmas, then three weeks before Christmas, the owner of the business told my client, it must be up and working by the 20th. December!
Two weeks is all I had, to fabricate one of the largest stretch face illuminated signs in Adelaide!
Because of the sheer size of it, 10800 mm. x 4600 mm., there were considerations that had to be taken into account, which don’t normally apply to smaller signs of this type. One of them was that we couldn’t effectively illuminate a sign this size with fluorescent tubes, as there would have been too many of them, and they would have cost the owner $8.000 @ year to run, according to his electrician, and more to the point, if one or two should stop working, it would have been a regular pain in the butt to keep changing them out. LED’s were briefly considered, but they were simply horrendously costly to begin with, so my client, who I was to do the job through, decided upon long neon tubes, especially made for the purpose. Ten year lifespan, and quite economical to run by all accounts. This suited me fine, at least I wasn’t going to have to wire up 108 fluro tubes in the small amount of time we all had to compiete the job.
The other consideration, was the tensioning of such a large banner. Normally an aluminium rope track is employed around the perimeter, and during installation, a lot of force is applied incrementally around the perimeter to gain tension. This is not an easy job, and can sometimes be a little hit and miss. Also, because of the sheer size, wind loadings had to be considered, and not simply wind blowing the face in, but side winds, causing sheer and vacuum along the face. We needed a tensioning system that would get the banner really tight. Now, there are some ready made aluminium extrusions out on the market, that can do this, but in my opinion, they were too light in construction, as well as the screw system they employed, which becomes nearly impossible to undo after a few months, because of electrolysis. I decided upon a steel frame, which would have all of the necessary strength, along with a tensioning system I had been messing around with in my spare time.
So, after a meeting at my clients shop along with the neon guys, we decided upon the final sizes of everything, and all left with tasks to do, and hopefully get it over the line by the 20th. December.
One of the first things I had to do was to fabricate a model of my tensioning system I had been toying with on paper for a while. I did this on Sunday, and had it collected by my client on Monday, so they could at least work out the banner dimensions, and have it cut and made in Melbourne. The system I came up with, uses an over centre catch, which has quite a lot of force for a small catch, three hundred kilograms in fact. The problem though, is that there is only 25 mm. movement on the action in compression, and a further 25 mm. in adjustment. I deemed this as insufficient, because on the day, banners can be either undersize, or oversize, and the industry is full of horror stories of trying to get ill fitting skins to tension up.
I decided to also have another set of adjustments on my steelwork for the catch to drop down to, as well as a four stage tab, which allowed another 80 mm. of adjustment. There was no way a banner was not going to fit my sign!
This is the prototype I made for the client. From this, I furnished some drawings for a structural engineer, who gave it the nod, we were GO!
Sixty catches were ordered and delivered, as well as all the steel I needed for the job. I decided to make the perimeter in sections, that lock together on site, also bearing in mind, that two guys in a bucket lift can only handle a certain length safely. Sixty of everything was cut, drilled, tapped, milled and welded, using jigs of course. The four stage plates had to be Tig welded to the 8.0 mm. rods, so they would fit inside the aluminium extrusions. All of this took one week.
After all the sixty pieces were put together, I then had to join them into sectioned lengths, in either 2300 mm. or 1800 mm. sections. Once this was done, I needed a sheet metal base, as well as a reflector panel, and a cover trim panel for each section. All of these sections were fitted together to ensure a close fit up.
Here, I am working on one of the corner sections.
Another corner section being assembled, prior to its reflector panel and trim being attached.
Detail showing tight fit and tolerances. Note the three threaded vertical holes for the catch, the catch only requires two of these, the third being if we need to lower the catch another 17 mm. The holes in the flat bars to apply the trims are also threaded. All up, I threaded 240 holes under the threading tool, which only took an hour!
One of the corner sections, showing detail of the joining tubes. The screws holding the tubes were set in milled slots, allowing adjustment if necessary.
Sixteen sections back from the powder coater, as well as their trims, all ready for assembly.
One of the corner sections assembled.
Different view of above section.
Now we can see the catches in place.
Tensioning system in place for a trial run.
More detail of tensioning system.
Now you can see how it all works.
Perimeter frame only took a few hours to install. Client was extremely happy! I was five millimetres out in my measurements, not bad! Wall was then painted white for light reflection, and fifteen adjustable vertical aluminium brackets, each measuring 4300 mm. long were installed. These hold the neon in place.
Boys applying the trim work after tensioning the face.
Tensioning system all tucked away.
This shot shows the sheer size of the sign, it’s huge!
Well, we DID get it over the line on the 20th!
But, it didn’t all go smoothly as planned. The installation of the neon took a little longer than the neon guys had bargained for, and the banner was late ex Melbourne. Once they boys started to thread the banner along the top rail, there were major problems, because of the sheer size and weight of it.
All up, a pretty tidy sign I think.
Monster Stretch Face Illuminated Sign For U Store It At Keswick, South Australia