While building a string of lights, I was faced with the problem of how to make this string of lights waterproof.
Ultimately, I installed the electronic components, which cannot be exposed to moisture, in a 3D printed transparent housing. In order for them to be finally waterproof, the electronic components had to be cast with casting compound.
This potting compound is transparent and does not conduct electricity. In addition, it is liquid at the beginning and then hardens later. Perfect for protecting electronic components from contact with water.
Of course, this doesn't just apply to fairy lights. Ultimately, other electronic components can also be protected from contact with moisture.
I have described how I did this in the following article.
Safety instructions
I know the following notes are always kind of annoying and seem unnecessary. Unfortunately, many people who knew "better" have lost eyes, fingers or other things due to carelessness or injured themselves. Data loss is almost negligible in comparison, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Because even the coolest project is not worth injury or other trouble.
https://www.nerdiy.de/sicherheitshinweise/
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Requirements
Required tool:
Required material:
Prepare the workplace
Since working with epoxy resin can quickly become very dirty or sticky, you should prepare your workplace accordingly.
To do this, you should cover your work surface. It is easier to throw away the old newspaper later than to remove the (possibly even dried) epoxy resin from the work surface. 🙂
You should also ensure there is a sufficient supply of fresh air. If possible, work outside or at an open window.
You can also support the ventilation of your workplace with a fan or fan.
This means that any fumes that may arise cannot be inhaled or are at least highly diluted.
Safety precautions
Safety precautions are at least as important as preparing the workplace.
These include at least
- Protective gloves
- Safety goggles
- Smock
- a suitable protective mask
You should prepare yourself so that the epoxy cannot come into contact with unprotected skin or even your eyes.
Prepare the casting mold
Depending on the structure of your project, you should prepare your casting mold for filling in the epoxy resin.
In this example shown, the LED elements of the 12V fairy lights are cast.
As you can see, the individual LED strips are...
...from the casting mold.
Since you want to cast the electronic parts completely in epoxy (because this is the only way to protect them waterproof), you should now make sure that the parts in question are completely surrounded by epoxy later.
The solution to this problem is to fix the electronics in the casting mold so that they are later completely covered with epoxy.
It is often enough to fix the electronic components (here the LED strip) in the casting mold with a little hot glue so that they no longer protrude from the casting mold.
So contribute in the necessary places…
...some hot glue on...
...and fixes the LED strip or all electronic components that need to be sealed watertight...
...like this in the casting mold.
The electronic components should then lie deep in the casting mold...
...that no part sticks out of the casting mold.
Other view.
Other view.
Prepare the casting compound
After you have prepared your workplace and the casting compound, you can now prepare the actual casting compound.
First
Put on protective equipment!
Casting compound often consists of two components, which must be mixed in a certain ratio.
To do this, read the operating instructions printed on the wrong device carefully.
As soon as you have completely read the clues on the wrong...
...you can prepare the casting compound.
Mix the two liquids in the correct ratio. A kitchen scale can be very helpful.
Of course, make sure that this kitchen scale either does not come back into the kitchen or is appropriately packaged/protected so that no residue of the casting compound can come into contact with food.
Once you have mixed the two liquids, you should mix them thoroughly.
For example, an old wooden ice cream stick or a wooden toothpick can be used. You can simply dispose of both after use. (But make sure that leftovers should not always be disposed of with household waste.)
Take up the casting compound
I often find it difficult to fill in the prepared casting compound. However, in my opinion there is a good tip that makes the whole thing much easier and cleaner.
Instead of pouring the potting compound directly from the “preparation vessel”, you can also draw the potting compound into an old syringe.
To do this, pull as much epoxy as you need into a...
...appropriate syringe
Fill in the casting compound
Thanks to the tip mentioned above, you can now pour the applied casting compound into the casting mold relatively easily and in good doses.
Now you can simply pour the drawn-up potting compound from the syringe into the potting mold.
This way you can check that the casting compound is filled evenly everywhere and is well distributed.
Other view.
Once you have filled in enough casting compound, you should now check again that the electronic components are covered everywhere by casting compound.
Other view.
Other view.
Other view.
Other view.
Other view.
Other view.
Other view.
If necessary, close the lid
Whether this step is necessary depends largely on how your casting mold is constructed.
In the example shown here, the cover of the LED elements is so close to the cast LED elements that it would probably no longer be possible to put it on correctly later.
That's why I recommend putting it on here when the casting compound has not yet hardened.
Other view.
Other view.
Other view.
Have fun with the project
I hope everything worked as described for you. If not or you have questions or suggestions please let me know in the comments. I will then add this to the article if necessary.
Ideas for new projects are always welcome. 🙂
PS Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you think it's cool that I share the information with you, I would be happy about a small donation to the coffee fund. 🙂
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