Potting compound alternatives

I've watched the whole motorsport wiring course now and bought some materials.

Question: Why is it so important to use the specific epoxy potting compounds RT125, V9500 etc?

I have potted out devices before with normal epoxy, Selleys Araldite.

With a boot at a branch point, I would have thought a flexible substitute like silicone would have been ideal (and a lot cheaper and easier to use).

Hello Jonny

The reason we are using ResinTech RT125 is that its quality and reliability are proven through years. Similar to RT125 there is TE Connectivity S1125. Another reason is that they designed to use in specific applications where others couldn’t withstand harsh environment. At the very end - if you satisfying with result with your potting compound and everything is working fine you can continuing using it.

So, I went ahead and ordered some ResinTech RT125 from Pro wire USA via eBay. (I'm in Australia). The item got shipped across several states until the item was declared contraband, probably destroyed by customs, and I was luckily refunded.