Sarath,
I tin my PCBs like this…..
Materials needed – Stannus Chloride (SnCl2 – Tin Chloride), Thio Urea (NH2CSNH2) and Hydrohloric Acid (Conc) (HCl). All these chemicals are available in Chennai. Stannous Chloride is a bit expensive – 100 Gms Rs400/-.
1. Clean and rub the Etched PCB with steel wool or razor blade.
2. For one litre of water, add 20 Grams of SnCl2, 100 Grams of Thio Urea and about 25ml of HCl and bring the mixture to about 60*C.
3. Drop the PCB into the concoction and happily watch the rapid tinning process – leave it for 5 mins.
The “liquid tin” thus prepared can be stored in glass bottle and reused several times. Use only glass or ceramic bowl during etching. I heat up the mixture in microwave (when XYL is not around). The mixture is a bit foul smelling after heating. So leave the MW door open for 10 minutes after heating. The problem with this method is that the coating is not as thick as you would get in a solder pot. Secondly, the tinning does not look shiny like the commercial ones. Thio urea is absolutely important to prevent growth of microscopic tin traces across tracks, rendering the PCB useless. Thio Urea crystallizes beautifully at the bottom when the mixture is stored away!
Cheers,
Raj VU3RGK
From: HamBrewers@yahoogroups.com [mailto:HamBrewers@yahoogroups.com] On Behalf Of Sarath
Sent: Tuesday, August 28, 2012 12:51 PM
To: HamBrewers@yahoogroups.com
Subject: [HamBrewers] Homebrewing PCBs
I have been making a few PCBs recently, I do not own a solder pot, and having trouble tinning these PCBs.
I read about some products that could be used be used to tin the PCBs called liquid tin and some tinning powders. I would like to know if such products are available here in Bangalore, Or if you all use any other methods, or tricks to tin the PCBs.
Regards,
-Sarath
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