Waterproofing Pixels

From doityourselfchristmas.com
Jump to: navigation, search

Disclaimers

The standard disclaimers pertaining to the information contained on this wiki page are listed here.

Need for Waterproofing

Over the last few years there have been many different types of pixel nodes coming from China. The waterproofing on the pixels vary from manufacturer to manufacturer. While many claim to have pixels with an IP68 rating (the highest) those claims are often exaggerated. Recent construction techniques like epoxy resin molded bodies have helped to make the units more waterproof, however the quality of the nodes often vary. The biggest weakness is where the wires enter the back of the pixels and how it is sealed. Silicone injection molded pixels have frequently had water leakage issues. The water can find its way into the pixel via flexing of the wires or simply by wicking up the wires due to temperature changes. Failure to properly waterproof pixel nodes can result in their destruction due to water damage.
2801pixelback1.jpg Badpixel1.jpg


Sandevices.com the manufacturer of the E680-E682 Pixel Controllers has the following note on its website that explains the issues with pixel nodes.

"There are additional considerations for outdoor displays. The first is waterproofing. Bear in mind these comments refer to the popular Chinese‐made pixel strings. First, it’s important to understand the original purpose of these pixels. They were designed to be installed in digital signs, pushed in from the back of the faceplate of the sign, in a pretty closely spaced grid. So, they are relatively waterproof, as in designed for outdoor use, but there originally intended application doesn’t subject them to direct rain or snow because they are pretty‐much shielded by the sign enclosure. The weak spot is that there are two sets of wires going into each pixel, two 3 or 4‐conductor flat cables. These two flat cables are just pressed against each other and they enter the pixel through a single hole in the silicone. The problem is that there is no silicone between the two sets of wires, and this not only creates a potential entry point for moisture, with a ‘hanging’ string, the weight of the string will tend to pull the silicone apart slightly, allowing a larger path for water entry. Some pixels are made from a pretty stiff silicone, others are made from silicone that’s a lot more flexible. Those made from the stiffer silicone are probably more inherently waterproof, but those made of the softer stuff do lend themselves to some additional waterproofing by a quick shot of hot melt glue between the two sets of wires. The silicone is soft enough that you can just jam the tip of the glue gun in, forcing the wires apart a bit, then you shoot in a dab of glue, and when you remove the gun the silicone snaps back and seals everything up tightly. I personally ran 40 strings of pixels this year, about 20 of each type. I did do the hot‐melt glue waterproofing of the softer pixels. All strings survived the season."


Waterproofing Techniques

The common methods of waterproofing pixel nodes are:

  1. Dip the entire node string in a bucket of Clear UV resistant Plasti Dip coating that has been thinned down with a solvent. See the video for a demonstration by RJ.
  2. Inject Liquid Tape into the back of each pixel node with a syringe. See the video for a demonstration by aussiephil.
  3. Apply Hot Glue to the back of the pixel nodes between and around the two flat cables.
  4. Apply GE Silicone II Clear Window and Door Silicone Caulk to the back of the pixel nodes between and around the two flat cables.


Avoid supporting pixel node strings by their own wire alone. Hanging the pixel node strings without support pulls the wires apart in the back of the node and it makes it easier for water to enter them. Common methods of supporting the pixel node strings include: attaching them to plastic strapping made for shipping boxes, attaching them to paracord or attaching them to PVC frames. Some people have recommended putting a small plastic cable tie around the wires where they enter the pixel to keep them from pulling apart.

Here is a good thread about how different materials hold up after exposure to weather.

Waterproofing Pixels Videos

There are several videos of different methods to waterproof pixels.
Plasti Dip Diping Pixel strings in Clear Plastidip
Liquid Tape Injecting Liquid Tape into the back of Pixel Nodes


Waterproofing Electrical Connections

Here is a interesting thread about different sealants for electrical connections on pixels. It has photos and discussion about effects of weathering on the various sealants.

Waterproofing Supplies

The following supplies are available from numerous vendors including A WarehouseFull and McMaster-Carr.
Clear UV Resistant Plasti Dip
Liquid Tape
Solvent to thin coatings
Syringe to inject into back of nodes
GE Silicone II Window & Door Clear Silicone Caulking (Only use Silicone II which is Neutral Cure not Silicone I which is Acid Cure!)
Hot Glue


Understanding IP Ratings

Items can be rated based on a standard classification system called an IP Rating. IP stands for Ingress Protection. While many Chinese manufacturers claim various IP Ratings, many people are suspect of the ratings claimed.

The IP Rating is a two digit number, like IP68. The first number is a measure of the physical protection the unit provides to solid objects. The second number provides a measure of the protection from liquids.

Solid particle protection

The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects.

Level Object size protected against Effective against
0 No protection against contact and ingress of objects
1 >50 mm Any large surface of the body, such as the back of a hand, but no protection against deliberate contact with a body part
2 >12.5 mm Fingers or similar objects
3 >2.5 mm Tools, thick wires, etc.
4 >1 mm Most wires, screws, etc.
5 Dust protected Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment; complete protection against contact
6 Dust tight No ingress of dust; complete protection against contact

Liquid ingress protection

The second digit indicates the level of Protection of the equipment inside the enclosure against harmful ingress of water.

Level Protected against Testing for Details
0 Not protected
1 Dripping water Dripping water (vertically falling drops) shall have no harmful effect. Test duration: 10 minutes

Water equivalent to 1mm rainfall per minute

2 Dripping water when tilted up to 15° Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position. Test duration: 10 minutes

Water equivalent to 3mm rainfall per minute

3 Spraying water Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect. Test duration: 5 minutes

Water volume: 0.7 litres per minute
Pressure: 80–100 kPa

4 Splashing water Water splashing against the enclosure from any direction shall have no harmful effect. Test duration: 5 minutes

Water volume: 10 litres per minute
Pressure: 80–100 kPa

5 Water jets Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects. Test duration: at least 3 minutes

Water volume: 12.5 litres per minute
Pressure: 30 kPa at distance of 3m

6 Powerful water jets Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. Test duration: at least 3 minutes

Water volume: 100 litres per minute
Pressure: 100 kPa at distance of 3m

7 Immersion up to 1 m Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion). Test duration: 30 minutes

Immersion at depth of 1m

8 Immersion beyond 1 m The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. Normally, this will mean that the equipment is hermetically sealed. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects. Test duration: continuous immersion in water

Depth specified by manufacturer


Related Links

Different Styles of Pixels
Controllers
Dumb RGB or Intelligent Pixels??
Things You Will Need To Get Started With Pixels
Pixel Wiring Colors
Pixel Connectors
Choosing a Pixel Voltage: 5V vs 12V
Power Supplies
Power Injection
Null Pixels
E1.31 Network Setup and Configuration