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Subject: Re: [Homebrew_PCBs] Re: Tin Plating

From: David Pickering <satdaveuk@...>
Date: 2013-09-25

I gave up on all that now because it doesnt warrent the time and exspense involved with DIY PCBs
The best cheapest and most effective way to protect circuit boards is to give them a quick light spray with servisol PVC spray
By using that you not only protect the copper clad from moisture and other elements and keeping its shine but also you can solder through it without problems if required at a later date.
Regards
Dave


From: designer_craig <cs6061@...>
To: Homebrew_PCBs@yahoogroups.com
Sent: Wednesday, 18 September 2013, 18:47
Subject: [Homebrew_PCBs] Re: Tin Plating

 
I have used the Sulfamic acid, Thiourea, and stannous chloride since 1973 to tin plate boards.

If you are having problems, make sure your chemicals he correct ones and fresh. You need Tin(II) chloride SNCl2 CAS 7772-99-8, Thiourea SC(NH2)2 CAS 62-56-6 and Sulfamic Acid H3NSO3 CAS 5329-14-6

Formula for various batch sizes:

100 mL 50 mL 25 mL
----------------------------------------------------
.5g Stannous Chloride 250mg 125 mg
2.0g Thiourea 1g 500 mg
3.0g Sulfamic Acid 1.5g 750 mg
100.0 mL Distilled water 50ml 25ml

Use a fresh batch each time the stuff doesn't last more than a day or so. Heat to 80 to 120 degrees and make sure you copper board is very clean and bright.
Read the MDS for the chemicals especially Thiourea it has health risks and is fairly nasty.
Craig