Liquid Tin before drilling or after?

Thread Starter

spinnaker

Joined Oct 29, 2009
7,830
I am about to use Liquid Tin for the first time. Yes I intend to take proper precautions. Should I Liquid Tin before I drill my holes or after?
 

beenthere

Joined Apr 20, 2004
15,819
Before - when you handle the board, the copper is exposed to the nasty on your fingertips otherwise.

Precautions? Just don't drink it.
 

Kermit2

Joined Feb 5, 2010
4,162
tin is pretty harmless, zinc, copper, lead, cadmium, antimony, chromium, and a few others are toxic. Zinc is sneaky, in that you can be exposed several times and not notice any problem or even that you were exposed, but then upon the N-th exposure you get sick almost immediately and from then on, with every exposure. Big problem with brass casting profession in the day.
 

jpanhalt

Joined Jan 18, 2008
11,087
@Kermit2
I believe the concern is not over metallic tin that is deposited on the copper. It is over the chemicals, including various salts of tin, that are included in the preparation to make the conversion coating work.

John
 

jpanhalt

Joined Jan 18, 2008
11,087
Old school delirium here. not a big solder pot of melted tin, just some stannous sulfate or something right?
I have no idea what you mean.

"Liquid Tin" is not stannous sulfate. It is tin (II) (stannous) fluoroborate and fluoroboric acid plus thiourea, based on its MSDS. The older Tinnit is apparently no longer made, but was not based on fluoroborate, as I recall. It was a dry solid. I could not find and MSDS for it.

John
 
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