Project Pierogi: The Krakow Light Display

Intro

A customer recently called, asking if I’d be interested in doing a unique job for them. An existing, decorative light display, featuring an image of the Cloth Hall in Krakow, Poland was in need of a refurbishment and a lighting upgrade. From the initial conversation, it would definitely be a project right up my alley.

Krakow light display installed at the Polish Club, Melbourne
Krakow light display installed at the Polish Club, Melbourne

Works for this customer are pretty typical. A light switch here, a power point there, nothing too spectacular. What made this different was the fact it was to be a feature of their club, not just some practically placed outlet, hidden away out of sight. Instead, it was a feature piece, on display for all to see. In fact, it would be the first thing to be seen by patrons when entering the restaurant, not only the heart of the club but also a pivotal meeting place for the Polish community here in Melbourne. No pressure then.

The scope for the job was simple, improve luminance of the decorative image and make it shine once again. This would all be done in a project I dubbed “Project Pierogi“.

Details Of The Krakow Light Display

This depiction of the historic building in the town square of Polands second largest city, is created from thousands of holes, punched into a single sheet of steel.

Existing condition of Krakow light display
Existing condition of Krakow light display

Measuring 150cm tall and 285cm across, this display is massive. Almost being the size of a standard sheet of mild steel (150cm by 300cm, 5ft by 10ft). Not to mention it heavy, really heavy. Its incredible bulk due to the perforated image being manufactured from 3mm steel. Adding to its mass is a 20mm x 20mm square hollow section (SHL) frame that boarders the sheet of steel and is riveted in place. This display screen fits over the top of a timber frame below it.

The timber frame itself is simple enough, being made up of just 4 pieces of 35x90mm structural pine, fixed together with butt joints and then reinforced at the corners with steel brackets. It’s this frame that is bolted to the wall, bearing the weight of the hefty metal screen that is placed on top of it.

Within this frame, 6 fluorescent light fittings (fluoros for short) were mounted, each screwed to the inside surface along the perimeter. 2 fluoros on each the top and bottom, and then a single fitting on each the left and right sides. These were operated by a single switch, mounted to the lower corner of the frame, with power being supplied by means of a 3 pin plug that would get plugged into the closest outlet available.

While fluoros might have been the goto option for this style of decorative lighting display back in the 90’s, this was never their intended purpose and as a result, the overall look was compromised.

The Problem With Fluoros

The original source of light for the light display was the six fluorescent tubes that lined the inside of the timber frame and shone through the array of holes of the perforated screen. As fluoros are meant for lighting up large, open areas, such as office spaces, these light fixtures were not correctly matched for the application.

Additionally, due to the placement of the batten fittings, being placed around the frame facing inwards, the light would wash out and become dim towards the centre. From the start, these were a terrible choice for this decorative purposes. 

But how to light such a big screen? How to make the lighting even? And could subtle, decorative light peeking out through the clustered holes even be observable when located in a vast, restaurant awash with even more harsh fluorescence light? If the new lights were going to achieve the desired effect they would need to be one thing above all else. They would need to be  bright. 

The LED Solution

LED strip lighting was the only possible option for the application. Light emitted from this rope of diodes is so bright its blinding, all the while using relatively little power.

Available in a range of brightness’s, colour temperatures and even in RGB (Red Green Blue) for colour changing applications, they are a perfect choice for feature lighting. This versatility creates brilliant lighting effects that can be either subtle and gentle or intense and focused. Given the relatively large room they would be tenant to, what was needed for the project was intensity. 

To simply replace the existing fluoro tubes with LED’s would have been the easiest solution but wouldn’t have given the even light needed. While it would have been brighter, the light would still have washed out towards the centre of the image. Not only this, but LED strip lighting are just that: long, thin strip of light. Much in the same way a fluoro tube is a long, skinny bar of light. If not diffused effectively, they would appear as lines of intense light from behind the screen and not improve the appearance in any way. To overcome this irregularity in luminance, a medium of diffusion would be necessary.

A specialty acrylic, design specifically for signage, would be the solution. This semi-transparent plastic uniformly spreads the light over the large area, reduces light ‘hot spots’ and overall ‘soften’ the unrefined light. 

Without this sheet of specilised plastic the LED light strips would have been disgustingly patchy, bright and harsh.

Logistics and Lockdowns

As time was already limited due to a busy schedule, it was decided to transport the display back to the work shop and complete works after hours.

The Krakow light display loaded up on the Eazytrailer, folding utility trailer, ready to take back to the workshop.
The light display loaded up on the trailer ready to take back to the workshop.

Another more pressing concern which lingered was the likely possibility that local government authorities would call a snap lockdown in response to growing COVID case numbers. If a lock down was to be enacted, the ability to work on site would no longer be allowed. 

To move such a large item from site back to the workshop, the trusty and versatile Easytrailer was recruited (read all about Project West: Easytriler/Harbor Freight trailer rebuild here). Despite the excessive weight of the display plus additional support structures on the trailer bed, the little utility trailer handled the bulk without any issues.

As it turned out, the call to move the project off-site was a valuable decision with the state of Victoria was plunged, yet again, into a stage 4 lockdown during the period of activities. If the gamble was taken to work on site, the project would have come to a screeching halt for weeks. Seeing as everything was localised to the workshop, progress could continue, regardless of health department restrictions.

Work Begins

Now back in the workshop, the first task was to remove all the crappy, existing fluoro light fittings. This was easy enough, a dozen minutes with a battery drill and the six lights plus cabling were all removed. Now all that remained was the frame, a simple timber rectangle. 

Existing configurations of fluorescent light fittings mounted in the timber frame
Existing configurations of fluorescent light fittings mounted in the timber frame
Timber frame with fluorescent lights removed
Timber frame with all fluorescent light fittings removed

A majority of tasks were to be done on this frame. A 9mm MDF back panel had to be put on, the internal surfaces were to be painted and most critically, installation of the new LED lights. The perforated screen, in comparison, the would simply need the 6mm diffuser acrylic fixed to it.

Before anything could be done, both the MDF and acrylic had to be laser cut to the exact size. By specifying the correct size, it would ensure a simple installation without the need for cutting or trimming. With this intention, a sheet of timber and plastic at 1450mm by 2950mm were ordered to be cut.

Measure Twice Cut Once

Measure twice, cut once is how the old saying goes and is relevant here. As mentioned just prior, the ordered size was 1450mm by 2950mm on the assumption the screen was a full sized sheet of steel – A standard sheet being 1500mm by 3000mm, or approx. 5ft by 10ft. As it turned out, the screen was not that of a full size sheet.

While it looked to be a standard size it was, in fact, 100mm shorter than this at only 2850mm. Because of the assumed length, both pieces were cut 100mm too long. Proving the other old saying that assumptions do make an ass out of you and me.

While it was lucky to be 100mm too long and not 100mm too short, it still meant having to trim the excess off the material. It would have been preferable to take both sheets back to the laser cutters to be accurately trimmed, those intentions were swiftly dashed however at the commencement of the prevailing lockdown. With freedom of movement severally restricted, an in house trim would have to do. 

The cuts were not perfect (when compared with a laser cut), but not terrible either, most critically they would finally be the correct size. All was right in the world once again.

Putting The Pieces Together

With all the adjustments to sheet sizes done, the MDF sheet could finally be attached to the back of the frame using timber screws spaced approx. 200mm apart. 

display frame on "work bench" (aka Easytrailer with a bunch of pallets) ready to be worked on.
display frame on “work bench” (aka Easytrailer with a bunch of pallets) ready to be worked on.

An added challenge to getting everything screwed together proper was the fact the frame was slightly out of square. Not only this, but there was a severe bow in the timber on its longer sides making the frame just that bit more wonky for good measure. In order to square everything up once again and get the bends out of the timber, the edges of the frame were lined up to the edges of the MDF, clamped firmly in place and then screwed together. The hope was that after all the effort of lining up edges it would have straightened out the crooked timber. Which lucky it did.

With the MDF backing securely fixed to the frame, it was time for a lick of paint on the inside of the enclosure. The reason to paint the inside was to ensure light from the LED’s would be reflected as much as possible within the box instead of being absorbed by any darker colours. It would be the best conditions for the LED’s to be visible through the perforated holes of the screen.

The paint used was a basic, white, two-in-one primer and sealer. Not only was this nice and bright, perfect for reflection of light, but would also act to seal the MDF from any absorption of moisture. Just over three coats of the primer was applied to the inside surfaces with the 2 litre tin more than enough and even some remaining for touch ups later on if required.

9mm MDF backing installed onto the timber frame, ready for painting.
Enclosure for light display, light box painted and ready for LED's to be installed
Enclosure for light display painted and now ready for LED’s

While the finish isn’t anything to brag about, its only primer after all, it was perfectly suitable for the application. It serves a functional purpose rather than an aesthetic one and will aid the LED’s to illuminate the display.

New LED lights

With the MDF backing finally on and painted, the new LEDs could be installed. For this refurb, four 12 volt LED kits, each prewired with 5 meters of LEDs, were necessary to effectively light the display. The LEDs are rated at 300 lumens per meter, equating to 1500 lumens per kit and equals a huge 6000 lumens for the sum total of the lights. This would definately be bright enough for what was needed.

12v LED light strip 5 meter kit used for the Krakow light display.
12v LED light strip 5 meter kit used for the light display.

Colour temperature is 5000K, a natural daylight colour and is ideal to contrast against the grey of the powder coated steel screen. If the temperature was lower, it would be too yellow, higher it would be too white or even blue. This temperature is perfectly balanced for such decorative purposes.

After a quick dry run of the layout, each of the prewired 5 meter lengths were positioned in such a way to give the most concentrated light for the design of the image. In the end this turned out to be 9 rows, in a kind of Christmas tree pattern, with even spacing throughout.

LED light strips arranged in rows within the enclosure, light box.
LED light strips arranged in rows within the enclosure.

Part of the reason for choosing a 5 meter kit was for the ease of installation. There is no soldering or terminations required for the LEDs unlike many alternatives currently on the market. Along with this, the light strips came preinstalled with double sided tape. Together, these features made the setup a breeze. All the was needed was to simply remove the backing off the double sided tape and stick into place directly onto the MDF.  

LED power supplies mounted to frame along left hand side.
LED power supplies mounted to frame along left hand side.
Close up of 12v 36w LED power supply
Close up of 12v 36w LED power supply

The power supplies for each kit were positioned down the left hand side of the frame, all in a row and all terminated to a single junction box behind the switch at the bottom left of the frame.

With all the new lights in place all that was left to do was to secure the diffuser plastic onto the screen.

Adding Diffuser Plastic

On the perforated screen there was no modifications necessary to be made, only the addition of the 3mm diffuser acrylic. After the drama of not measuring the correct size and the subsequent need to trim off the excess, the resized sheet of plastic fit neatly into the RHS border of the screen.

Diffuser plastic attached to the perforated screen.
Diffuser plastic attached to the perforated screen.

The acrylic was then secured in place with liquid nails construction adhesive. Any area of the screen where there was no holes present was smothered with the adhesive to ensure a strong bond between plastic and steel. It was then left to set over night before being placed onto the frame.

There was some worry the rows of the LEDs would still have been visible through the perforations of the screen even with the diffuser material. Thankfully, once all together it wasn’t possible to make out the cords of light, instead the LEDs provide a wonderful, bright, warmth to the image.

With all the modifications on the existing light display completed, all that was left to do was install the finished product on site.

Installation On Site

Getting the project completed in the workshop was easy, the hard part was when it came time for the light display to be installed at the club. The install date had to continuously be postponed, until lockdown conditions were eased. Once this eventually happened the install was good to go.

Frame of the light display mounted onto the wall, LED's turned on for test.
Frame of the light display mounted onto the wall, LED’s turned on for testing.

The intended location at the club was in the main dining area, on a gypsum covered brick wall. To securely fix it in position, a combination of Dynabolts and masonry bolts were used. Each of these fixings are rated at holding 300kg a piece, there would be no trouble holding up the almost 100kg of the display.

It was tricky to mount the frame to the wall given its size, it required teamwork along with safe lifting to persuade into position. While still not as cumbersome as the much heavier metal screen, it wasn’t a packet of peanuts either. With four willing helpers, the frame was eventually located into position on the wall. Once there, a single bolt was used to temporarially hold the structure in place all the while frantically working around to each corner drilling and fastening the masonry bolts to hold it up firmly against the Gyprock covered brickwork.

Additional brackets were also used for even greater support of the frame. The combination of fixing at each corner plus the extra brackets hold the frame firmly in place, so much so, it could support the mass of a full grown electrician without a hint it would budge.

Just prior to putting the screen up and onto the frame, there was a small amount of wiring that needed to be done. The original plan was to have a cord and plug come out of the top right of the frame and plug into an existing power point. However, this plan ended up being changed last minute as the power point in question was not in a good spot relative to the light displays final location. As a result, the configuration was altered to suit the onsite layout. This actually turned out to be a blessing in disguise, as the cord and plug could be neatly hidden away.

Krakow light display as installed on site
Krakow light display as installed on site

Finally the main event, the perforated screen was lifted into place and slotted over the timber frame, again with the assistance of a strong and willing crew. They, along with myself muscled the screen over the frame and once there was fixed in place using a series of bolts drilled into the timber.

The job was done.

Conclusion

Krakow light display as installed on site
Krakow light display as installed on site

Seeing the screen lit up, mounted high up on the wall was a rewarding end result. The final product really did pay off for all the efforts put in and the combination of LEDs and diffuser material meant the lighting effects were bright and even.

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Baden Jones
Baden Jones

By day a controls electrician, by night blogger for RB42 – fascinated by new and emerging technologies, automation, manufacturing, electric vehicles and of course my first, true love Formula 1.

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