I have recently learned about this technique which I think is wonderful because allows you to design a simple enclosure and forget about the weather, waterproof, shocks vibrations...
Also, if I understand correctly, the whole block acts as a radiator, so it would help the hotter components.
I was about to buy my first resin and do some testing, when I realised that a single cartridge costs around $300 No matter how small your circuit is, you're going to spend $20 or $30 on just the sealing!
I wonder if any of you guys have experience with this and could recommend any "white label" resin for DIY purpose and human prices.
Long ago we used to buy potting compound from Master Bond. They had various sizes available, but no idea if they're still in business. You can also find electronics-safe hot glue in smaller quantities at Digi-Key.
My former company used to build control boxes for a local motorcycle company. By their specs, we used two-part epoxy. Mixed only what we needed for the number of boxes. The result was as thin as water and the pour into the box took considerable time because of air bubbles that had to be removed by tipping the box in various directions to let the air escape. If your potting is thick, you will never be able to get all the air out and will have pockets with no potting compound.
Moreover, the boxes had to have some type of connection to the outside world. Their boxes were machined for automotive connectors that were water tight. However the box openings were never perfect fits and had to be sealed with RTV and let cure before potting. If you have any insulated wires that must connect to the electronics ni the box, you will NOT have a water tight product. There is air in the wire strands and air has moisture and changes in air pressure will eventually move the air moisture into your box.
As mentioned before, unless your potting compound specifically states it will act as a heat conductor, the potting will SEAL IN the heat.
There is NO magic in potting electronics.
You can typically reduce resin usage by 50% or more, and simultaneously increase the thermal conductivity by pre-filling large voids with dry sand, gravel or glass beads.
For hobby use I would recommend the use of two part soft silicone transparent "self repairing" gel.
Buy the twin pack type that allows you to only only mix what you need for a single pour.
I use Ray Tech Magic Gel which is about $ USD 70 per liter.
Wow man, thanks! the price it's really good, I will definitely give it a try
Can you explain a little more in detail how prefilling voids? and why that affects to the thermals?
No matter how small your circuit is, you're going to spend $20 or $30 on just the sealing!