Help me pick Lead-Free Tin and Alkyd Conformal Coating

Thread Starter


Joined Apr 27, 2023
Hi everyone, I have recently joined this forum and I come with a couple questions for you.

A client of mine (a company) wants me to change some SMD resistances from a group of PCBs. They have given me a document with details for the process, where they indicate which resistances are to be taken, dimensions of the new ones and other details. Two of the indications are to use lead-free tin (without specifying any brand) and to use Electrolube´s DCA SCC3 conformal coating.
I don´t have these items so I have to buy them, and there come these two questions.

Question 1 is about the tin. I have understood that lead-free tin is alloyed either with silver, copper, both, or even gold. I would like to know which one I should buy. Since there is no specific demand from the client, I´d be buying the cheapest, but first I´d like to know some differences or characteristics of each.

The second question is that the brand Electrolube is not available in Uruguay, not even for shipping. According to its datasheet, DCA "is a flexible, transparent and unique modified alkyd conformal coating specifically designed for the protection of electronic circuitry.". I have to find a similar coating, given that I´m going to remove only a specific area of the PCB´s coating. I assume that the most important item to check is the chemistry type, but I couldn´t find any "alkyd" coating and I have zero knowledge on chemistry, so I´d appreciate some help on this subject.

Thank you in advance for your help